Landslides under Microscope

I-40 rock slide cleanup to cost up to $10 million.

2009-10-27T22:37:00.000-07:00

Engineers have established a $2 million to $10 million plan to clean up a rock slide on Interstate 40 near the North Carolina-Tennessee line. The state Department of Transportation said unstable rocks will be removed first and then large boulders will be blasted into smaller pieces. Rocks removed from the side of the mountain and pieces of blasted boulders will be used to construct a ramp up to the top of the slide, which is 150 feet high and 200 to 300 feet wide. A pulley system will be installed on the ramp to climb to the top of the slide and remove rock. Crews will work from the ramp removing rocks top to bottom. Workers will chisel off rock and continue blasting to stabilize the area.

This aerial photos of the I-40 rock slide near the Tennessee -North Carolina border were taken by pilot Lester Bishop of Hendersonville.

The general idea for the cleanup is to blast the debris from the top so that it falls down the sides of the slide area and not straight ahead across the eastbound lanes into the Pigeon River, said Joel Setzer, the regional engineer with the state Transportation Department. After debris is cleared, temporary asphalt will be laid, followed by permanent asphalt in the spring. Officials have estimated that workers could take up to three months clearing the interstate in a steep section of the rugged Pigeon River Gorge.

Rock slide problem on Interstate I-40. Video and Pictures.

2009-10-26T19:36:00.000-07:00

It could take up to three months to completely clear debris on Interstate 40 after a rock slide early Sunday morning closed the highway in both directions at mile marker 3 in Haywood County, according to officials with the N.C. Department of Transportation. The slide happened about 2 a.m. near the Tennessee border. The large boulders crashed through mesh fences designed to stop smaller rocks, said Joel Setzer, a division engineer with N.C. DOT. Rock bolts, which the pin rock blocks into more stable rock, now poke through the massive pile of debris.

I-40 rock slide at mile marker 3 in the Pigeon River Gorge. 10/26/09--Bill Sanders

It's tough to determine” the cause of the rock slide, but Setzer said the freeze and thaw of recent rains could have contributed. Some water rushed down the rock face near the slide, and other areas of rock were visibly wet from the westbound lanes of the highway Sunday afternoon. Without the preventative measures of fencing and rock bolting, a “more significant” rock slide could have occurred in this area earlier, he said.

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Mudslide threat in La Canada Flintridge and Glendale. Video.

2009-10-14T18:12:00.000-07:00

Los Angeles County authorities said the communities most in danger of being hit by mudslides overnight included Big Tujunga Canyon, La Canada-Flintridge, La Crescenta and Glendale.
Authorities were watching the amount of rain that fails, the type of soil it falls on, how saturated the soil becomes and so forth. The L.A. County Sheriff's department is advising residents of flood-prone areas to be ready to get out within minutes, even without being told. They point out that mudslides can occur even if the rain stops.

Video and Photos of Nile Valley landslide near Naches River.

2009-10-13T18:21:00.000-07:00

Governor Chris Gregoire declares a state of emergency following the huge Nile Valley landslide. The landslide completely wiped out a section of SR-410, isolating people from their homes. But, that's only half the equation, water is another issue, the Naches River has been diverted from it's original path, flooding homes and the roadway. Currently, the river is low, rain and snow will only make things worse this spring.

A landslide slid across State Route 410 at 6 a.m. Oct. 11, 2009 completely blocking the highway about 10 miles west of Naches, just west of the Woodshed Restaurant. The slide went completely across the Naches River as well. This photo is taken looking east; the Nile Road is just visible in the lower right of the photo. The day after a a landslide blocked State Route 410 and the Naches River water from the Naches River continues to flood over Nile Rd. and onto nearby farms on Monday, October 12, 2009. A landslide slid across State Route 410 at 6 a.m. Oct. 11, 2009 completely blocking the highway about 10 miles west of Naches, just west of the Woodshed Restaurant. The slide went completely across the Naches River as well. This photo is taken looking southeast; State Route 410 is to the left of the river while the Nile Road is to the right of the Naches River.

Massive landslide blocks Naches River, Washington, causing residents to evacuate.

2009-10-11T18:17:00.000-07:00

A massive landslide about 10 miles west of Naches has closed Highway 410, destroyed a home and diverted the Naches River. Fear of flooding from the river has prompted authorities to begin evacuating residents. Several other homes have been damaged as water from the Naches River found its way around the blockage through private property and back into the river channel, said Robert Cunningham, a Bureau of Reclamation foreman who surveyed the area late this morning.

An aerial view shows a landslide blocking State Route 410, Sunday, Oct. 11, 2009, west of Naches, Wash. The landslide diverted the Naches River and damaged one home.

The slide has destroyed a section of Highway 410, shoving about a quarter of a mile of pavement on Highway 410 into the Naches River. And the hillside still hasn't settled down. "It could be several more days until our crews can go back in there and address the damage to the road, which is severe," said Meagan McFadden, DOT spokeswoman.

Photos of catastrophic landslides in La Trinidad, Philippines.

2009-10-09T19:29:00.000-07:00

Dozens of landslides in the rain-soaked mountains of the northern Philippines killed up to 200 people yesterday. The latest calamity brings the total death toll to more than 400 in the Philippines' worst flooding for 40 years.

Rescue workers search for victims amid the ruin of a house after a landslide that destroyed several houses Friday, Oct. 9, 2009 in La Trinidad, Benguet province north of Manila, Philippines. Typhoon Parma struck northern Philippines, swamping many provinces in the mountainous north and dumping more rains in Manila and nearby regions that were already sodden by a previous storm.(AP Photo).

Back-to-back storms started pounding the country's north last month. About 100 people were feared dead in landslides along the Cordillera mountain range, about 125 miles north of Manila. Landslides blocked the roads to the mountain city of Baguio in the heart of the Cordillera region and exact figures were hard to get. In the south, in Pangasinan province, heavy rain prompted authorities to discharge excess water from swollen dams. The resulting deluge inundated 30 towns.

Mudslide protection is set in La Crescenta, California. Video.

2009-10-07T18:53:00.000-07:00

During the Station Fire, firefighters lit backfires on the hillsides to protect the homes in La Crescenta, but now there is no vegetation to protect homes from mudslides. Experts say mudslides are inevitable this winter season, even with the slightest amount of rain. Officials with the USGS said that the worst-case scenario is mud and rock flows the size of a football field and 60 feet deep could come sliding into foothill communities.

Officials are taking the mudslide threat very seriously. Materials have been set up in Glendale for flood defenses, including stacks of straw waddle -- hose-like strands of straw that can be unbundled to soak up floodwaters when lives or property are threatened; pallets of sandbags already filled and ready to go when needed; and stockpiles of concrete K-rail to be placed along streets when already flooded.

Illegal construction is blamed for Sicily's fatal mudslide.

2009-10-04T18:09:00.000-07:00

Poor drainage caused by illegal construction was blamed for mudslides that killed at least 20 people in eastern Sicily on Friday, with dozens missing and hundreds more injured. Dozens of buildings collapsed, leaving hundreds of people homeless in the worst floods to strike Italy since 1998.

Mechanical diggers clear a road after mudslides hit the village of Scaletta Zanglea near the Sicilian city of Messina October 4, 2009. Italy's Prime Minister Silvio Berlusconi pledged on Sunday 1 billion euros ($1.45 billion) for areas threatened by landslides, after heavy rains and mud killed at least 22 people in Sicily.

The head of the Italian Civil Protection Service, Guido Bertolaso, directly blamed the construction of houses without permits - a practice rampant in Sicily and around Italy - for the deaths.

Houses are buried by debris and mud a day after mudslides hit the village of Giampilieri near the Sicilian city of Messina October 3, 2009. The death toll from rainstorms and landslides in Sicily rose to 20 on Saturday and Prime Minister Silvio Berlusconi said the number of victims could more than double as 30 people were still missing. REUTERS/Antonio Parrinello (ITALY DISASTER ENVIRONMENT).

Legambiente, Italy's leading environmental group, had been warning about the dangers in the area, saying that many of the now-destroyed houses had been built in deforested valleys with no consideration for drainage, making the tragedy inevitable.

View of Scaletta Zanclea after torrential rains and mudslides swept through the Sicilian town on October 1. (AFP/Mario Laporta).

Images of devastating earthquake-triggered landslides in Indonesia.

2009-10-03T18:38:00.000-07:00

The death toll from Indonesia's massive earthquake will likely double as officials on Saturday reached rural communities wiped out by landslides that buried more than 600 people under mountains of mud, most of them guests at a wedding celebration. Roughly 400 people were at a communal wedding in Pulau Aiya village when Wednesday's 7.6 magnitude quake unleashed a torrent of mud, rock and felled palm trees, said Rustam Pakaya, the head of Indonesia's Health Ministry crisis center. "They were sucked 30 meters (100 feet) deep into the earth," he said. "Even the mosque's minaret, taller than 20 meters (65 feet), disappeared."

This is an aerial view of an area affected by earthquake-triggered landslide in Padang Pariaman, West Sumatra, Indonesia, Saturday, Oct. 3, 2009. Wednesday's 7.6 magnitude temblor devastated a stretch of more than 60 miles (100 kilometers) along the western coast of Sumatra island.(AP Photo/Dita Alangkara).

Virtually nothing remained of four villages that had dotted the hillside of the Padang Pariman district in Indonesia's West Sumatra just three days ago, said officials and an Associated Press photographer who flew over the devastated area.

The number of fatalities in the disaster will jump to more than 1,300 if all those people are confirmed dead. The government's death toll on Saturday held steady at 715, most reported in the region's badly hit capital of 900,000, Padang, where aid efforts are concentrated. As many as 3,000 people had been declared missing before news about the obliterated villages emerged, while 2,400 were hospitalized and tens of thousands of people are believed to have been displaced.

An AP photographer who flew over Padang Pariaman district in a helicopter saw several landslides in the area.Damaged houses are seen in this aerial image of an area affected by earthquake-triggered landslide in Padang Pariaman, West Sumatra, Indonesia, Saturday, Oct. 3, 2009. (AP Photo/Dita Alangkara).

Mudslides in Sicily kill 50, several buildings collapsed.

2009-10-02T20:10:00.000-07:00

Italy's government declared a state of emergency on Friday as the number of people killed in mudslides in Sicily rose to 50. Hundreds of people have been left homeless after the mudslides, triggered by heavy rain, and which have caused the collapse of at least 10 buildings. "There are some 20 dead and 30 missing but at the end there will be at least 50 deaths," Berlusconi was quoted as saying late on Friday by the Italian news agency ANSA.

Map of Italy showing the location of Messina on Sicily where at least 14 people have died after torrential storms hit the northeast of the island.

Some 250 millimetres of rain fell on northeastern Sicily in the space of a few hours on Thursday, triggering mudslides that collapsed two buildings, carried off cars and cut off roads throughout the region.

An aerial view of a collapsed building in the village of Scaletta Zanclea near the Sicilian town of Messina.

Rescue workers and sniffer dogs searched Friday for survivors in the rubble of the two buildings and in numerous communities in the Messina region cut off by mudslides, but searches were halted overnight due to dangers to rescuers.

Mudslides included one that stretched over 3.5 kilometres, cutting off communications and sweeping away dozens of cars between Messina and several coastal towns south of the city in the northeast of the island. Witnesses said that in some towns such as Molino, south of Messina, the mud was up to seven metres deep.

Powerful earthquake kills 200 people in Indonesia, thousands are trapped.

2009-09-30T18:05:00.000-07:00

A disaster management official says at least 200 people have been killed by the powerful earthquake that struck western Indonesia. Priyadi Kardono, a spokesman for the National Disaster Management Agency, says the deaths were counted in the coastal Sumatran city of Padang, following Wednesday's 7.6 magnitude quake. Kardono said Thursday that about 500 buildings collapsed in Padang — a sprawling regional capital of 900,000 people.

The quake has trapped thousands in collapsed buildings, while triggering landslides and fires. Blackout and heavy rain are making it difficult to assess the damage, and the death toll is expected to rise sharply on Sumatra island.

People stand near a collapsed shopping mall after an earthquake hit Padang, on Indonesia's Sumatra island September 30, 2009. A 7.6 magnitude earthquake struck off the city of Padang on Indonesia's Sumatra island on Wednesday, killing at least 75 people and trapping thousands under rubble, officials said.REUTERS/Muhammad Fitrah/Singgalang Newspaper (INDONESIA DISASTER ENVIRONMENT).

The last strong earthquake struck Indonesia only few weeks ago. It triggered several landslides, causing significant damage in West Java.

Residents and rescue workers search for victims at the site where an earthquake-triggered landslide hit a village in Cikangkareng village, West java, Indonesia, Sept. 4, 2009. (AP Photo/Irwin Fedriansyah).

Leaky dam built on old landslide causes flood problems in Seattle area.

2009-09-28T17:52:00.000-07:00

King County has declared a state of emergency as the Howard Hanson Dam began showing disturbing signs of vulnerability after a torrential rainstorm in January. The dam, located in the Cascade foothills east of Seattle, has prevented major floods in the Green River valley since it was completed in 1962. However, that changed when last winter's heavy rains weakened a hillside next to the dam. A record 15 inches of rain fell in 12 hours on the Green River's upper watershed in January, sending torrents into the 235-foot-high dam's reservoir. The reservoir rapidly filled 6 feet higher than ever before.

In this Sept. 23, 2009 photo, the downstream side of the Howard Hanson Dam is shown as viewed from the top of the dam, near Ravenswood, Wash. Residents face the all-too-real prospect that the river will gush past a leaky upstream dam and swallow up their homes once the rainy season starts in November, devastating a heavily developed area in the Seattle suburbs that is a vital hub of commerce. (AP Photo/Ted S. Warren).

The dam held the water back and remained sound. But at the high water levels, engineers saw worrying signs within the dam's right abutment, a 450-foot-wide pile of rock deposited by a huge landslide 10,000 years ago.

Workers use a drill to make holes that they will inject grout into to strengthen the Howard Hanson Dam.

As a temporary fix, the Army Corps of Engineers is spending $8.9 million to inject grout into the abutment, forming a shield to lessen the seepage. Without such work, Col. Anthony Wright, the corps' Seattle District commander, said there would be a 1 in 3 chance this winter for flooding in the Green River Valley. As permanent measures, the corps hopes to create a concrete wall the length of the abutment and reaching down to bedrock — designed within a year and finished after two years of construction — a project that could cost up to $500 million.

About 25,000 people live on the valley floor, which includes parts of the cities of Kent, Auburn, Renton and Tukwila, but hundreds of thousands work, shop or travel there daily. State officials say 22,000 people might have to be evacuated in a flood.

Rock Slide at Dam Site in Chamera of Himachal.

2009-09-26T19:46:00.000-07:00

A landslide has injured three workers and caused considerable damage to a dam site of a power project in Chamba district, according to MyHimachal.com.Huge rocks and and debris fell on the dam site of Chamera III project being executed on Ravi River, about 40 kilometers from Chamba town.

Two power cranes at the construction site collapsed as the result of rock slide. Officials say that the damage would delay the project.

Landfill collapses resulting in "rubbish" landslide.

2009-09-25T21:54:00.000-07:00

Efforts at trying to put out the fire at an illegal dumpsite in Kampung Sungai Kertas, Ulu Yam, Malaysia, turned disastrous when part of the landfill collapsed, burying livestock and injuring a Bangladeshi worker, the Star Online reports.Tonnes of rubbish, earth and water came crashing down 40 metres on two livestock farms on Wednesday, drowning cattle and goats.

According to the newspaper, “the Selayang Municipal Council (MPS) had closed the dumpsite a year ago but irresponsible dumpsite operators had burnt the rubbish, causing an underground fire that was burning for the last five months." Two weeks earlier, the MPS and Fire and Rescue Department had dug a deep trench at the site and filled it with water in a bid to put out the fire. However, the weakened soil beneath the pile of rubbish gave way, and water came gushing down, bringing with it earth and rubbish.

Landslide and floods kill four in Turkey.

2009-09-24T03:57:00.000-07:00

The state-run news agency says heavy rains in northeast Turkey have triggered floods and a landslide that killed 4 people. One person is reported missing.

Map of the centre of Istanbul, locating the areas worst hit by floods. Turkey's government came under fire on Thursday over ramshackle planning in Istanbul, a day after killer floods swept away cars and bridges in what the prime minister called the "disaster of the century."(AFP/Graphic)

A survivor tries to collect her belongings two days after flash floods in Ikitelli, Istanbul, Turkey, Friday, Sept. 11, 2009. Flash floods gushed across a major highway and a commercial district in Istanbul Wednesday, killing 31 people. Authorities say they are bracing for more heavy rain in Turkey as rescuers continue searching for nine people dragged away by flood waters in the country's northwest.(AP Photo/Ibrahim Usta) .

The Anatolia news agency says three people were killed near the town of Borcka, in Artvin province, when their house collapsed in a landslide late Wednesday.

Safety nets are to protect slopes in slums of India

2009-09-24T00:30:00.000-07:00

To minimise risk from landslides caused by monsoons, which are common on unstable terrains, the Indian state government will now put up nets instead of constructing retaining walls, to protect slum-dwellers. At a meeting held between Mhada officials, the BMC and the police on Wednesday, it was found that the nets may work as an alternative to safeguard places where a retaining wall cannot be built. There are 49 landslide-prone spots, out of a total of 107, where it is technically not possible to construct a wall.

There are 77 slums, most of them located in the eastern suburbs like Kurla, Ghatkopar and Chembur, where 9,904 hutments dot the hillsides prone to landslides during the monsoon.

Landslides during the monsoon, in the last 17 years, at the seven hillocks in Kurla-Saki Naka claimed 220 lives. The maximum number of fatalities occurred during the 26/7 floods when 73 people died.

Mudslide prevention works in Jesusita burn zones, California. Video.

2009-09-15T19:00:00.000-07:00

Efforts to reduce the risk of devastating mudslides and flooding began Tuesday in the area burned by the Jesusita Fire. Fixed-wing aircraft will spend the next three weeks dropping hydromulch on burned areas. The mulch, which was used following the Gap Fire in Goleta, will help prevent mudslides or debris flow in the event of heavy rains. The true test of the hydromulch will come this winter if the predicted heavy rains materialize. Officials say there is a small chance the mulch may not hold up the hillsides if winters rains are extremely heavy.

Rejlated articles:

How to protect your home from mudslide. A manual from Draper.

Mudslides after Wildfires and Preventive Measures.

New video of La Jolla landslide, California.

2009-09-14T22:44:00.000-07:00

News 8 released a new video of the La Jolla landslide nearly two years ago. A city-hired contractor was recording as Soledad Mountain Road first buckled. The city came up with the eight-minute video to use as part of its defense in the case, but elected not to show it. Instead, lawyers representing homeowners submitted it to the court as their own evidence.

Landslide at the Rest and be Thankful beauty spot causes traffic chaos.

2009-09-08T18:10:00.000-07:00

A landslide closed the A83 at the Rest and be Thankful beauty spot yesterday, as storms battered the West Coast and Central Scotland, disrupting rail services, ferry sailings and causing traffic chaos.

A landslide at the Rest and be Thankful, on the A83 west of Loch Lomond, closed the road to traffic.

The slip on the A83, west of Loch Lomond, which happened following heavy rain, covered both lanes under several feet of debris. The road was shut in both directions between the A814 at Arrochar and the A815 turn-off near Cairndow in Argyll, police said. It is interesting that in 2007, the road was closed for several weeks after around 400 tons of soil and rock fell close to the spot of yesterday’s landslide.

Landslides kill two in a popular ski area in Chile.

2009-09-07T18:10:00.000-07:00

Landslides have swept through a popular ski area in Chile, killing two people and stranding about 1,300 foreign tourists. Police say the slides blocked portions of the 30-mile (50-kilometre) highway between the capital of Santiago and the Farellones ski centre to the northeast.

The first slide on Sunday buried homes and cars and swept a woman into a river, killing her. A second slide on Monday swept away buildings at a mining company, killing a guard and injuring eight people. Officials blame the slides on heavy rains that have fallen in place of customary winter snowfall.

People try to recover a vehicle stuck in the mud after a landslide near Farellones in the outskirts of Santiago, Monday, Sept. 7, 2009. At least two people died, officials said.(AP Photo/Santiago Llanquin).

Police officers inspect next to a house destroyed by a landslide on the road to Farallones Ski Center, outskirts of Santiago, Monday, Sept. 7, 2009. (AP Photo/Santiago Llanquin).

Workers clear a road to Farallones Ski Center blocked by a landslide in the outskirts of Santiago, Monday, Sept. 7, 2009. (AP Photo/Santiago Llanquin).

Wildfire no longer threatening LA-area communities but mudslides?

2009-09-05T17:32:00.000-07:00

The fire, one of the largest in Southern California history, was 49 percent contained by early Saturday afternoon after crews built protective lines on the northwestern flank near Santa Clarita, according to Forest Service spokeswoman Jan Ulrich. Fire agencies have spent $37 million to fight the blaze, which started Aug. 26 and has scorched 154,655 acres.

Map showing the areas affected by wildfire. (AFP/Graphic).

The burned hillsides in the Angeles National forest run to the edge of Tjunga, Calif, Thursday, Sept. 3, 2009. The blaze was 38 percent contained Thursday, up from 28 percent the previous day. The fire now measures 147,440 acres, or 226 square miles, and is one of the largest wildfires in Southern California history (AP Photo/Chris Carlson).

However, more trouble could arrive with the winter rains. Mudslides and debris flows are common in burn areas during the rainy season. With little or no vegetation left to anchor the soil, hillsides can fail with disastrous consequences.

Firefighters look for hot spots on a burnt landscape in Acton area in California August 31, 2009. REUTERS/Gene Blevins (UNITED STATES ENVIRONMENT DISASTER IMAGES OF THE DAY).

Many residents in Monterey County say that erosion is already underway. Lawn piles of dirt and stone came down shortly after the flames went out, and that's without any rain hitting the slope.
"If it burned clean behind your house, you're going to need to get some sandbags come the rainy season," explained Nathan Judy, U.S. Forest Service. Judy explained to Eyewitness News that now is the time for homeowners who live near the fire-stripped slopes to start preparing for possible slides.

Mumbai landslide kills 12 people in India.

2009-09-04T00:03:00.000-07:00

At least 12 people have been killed in a landslide in a suburb of the Indian city of Mumbai, officials said. It is not clear whether more people are trapped under the rubble. Rescue operations are still ongoing. According to police the incident took place in the suburban Andheri area due to the heavy rain and water logging in the lower areas. Landslide hit the Lal Bahdur Shastri Nagar slum at Sakinaka early this morning, damaging over 20 houses, Additional Commissioner of Police Amitabh Gupta said.

Unfortunately, more than half of Mumbai's inhabitants live in makeshift shanty towns and slums. In 2000, at least 60 people died in landslides in the city. The victims in that instance were from a community of slum settlers in eastern Mumbai.

Earthquake-triggered landslide buries a village in Cianjur, West Java, Indonesia. Photos.

2009-09-03T01:00:00.000-07:00

There are some pictures of the fatal landslide that buried a village in Cianjur in West Java, Indonesia.

Rescuers for victims after an earthquake-triggered landslide buried a village in Cianjur, West Java, Indonesia, Thursday, Sept. 3, 2009. At least dozens of people were killed and another dozens were missing after a strong earthquake rocked southern Indonesia, unleashing mudslides that buried villagers in their homes, disaster management officials said Thursday.(AP Photo/Irwin Fedriansyah).

Villagers walk on rocks from an earthquake-triggered landslide in Cianjur, West Java, Indonesia, Thursday, Sept. 3, 2009. (AP Photo/Irwin Fedriansyah).

Indonesian soldiers climb rocks from an earthquake-triggered landslide in Cianjur, West Java, Indonesia, Thursday, Sept. 3, 2009 as they survey the damage. (AP Photo/Irwin Fedriansyah).

Villagers look at the site where an earthquake-triggered landslide hit houses in a village in Cianjur, West Java, Indonesia, Thursday, Sept. 3, 2009. (AP Photo/Irwin Fedriansyah).

Powerful earthquake triggers catastrophic landslide in Indonesia.

2009-09-02T18:10:00.000-07:00

The 7.0-magnitude temblor jolted the Indonesian island of Java earlier in the day, killing at least 44 people and injuring more than 400, according to the National Disaster Coordinating Agency. The quake triggered a landslide in Cianjur, trapping residents inside their homes. The landslide buried at least 11 homes where 32 people live, local officials said.

The earthquake rocked high-rise buildings in Jakarta, prompting a mass evacuation in the capital's central business district. More than 700 structures collapsed or were badly damaged in towns and villages in hardest-hit West Java, said Social Affairs Ministry official Mardi.

People stand outside a devastated house in Tasikmalaya, West Java, after a magnitude 7 earthquake rattled southern Indonesia. Thirty-three people were killed, but officials expected the death toll to rise. ( Pikiran Rakyat Daily / Associated Press ).

People look at an earthquake-damaged home in the West Java town of Sukabumi. The underwater quake struck less than 123 miles south of Jakarta, Indonesia, at a depth of about 30 miles, the U.S. Geological Survey said. (AFP/Getty Images).

The U.S. Geological Survey said the underwater quake was magnitude 7.0 at a depth of about 30 miles. The Indonesian Meteorological and Geophysics Agency put the strength at 7.3.

Indonesia, a vast archipelago, straddles continental plates and is prone to seismic activity along what is known as the Pacific Ring of Fire. A huge quake off western Indonesia caused a powerful tsunami in December 2004 that killed about 230,000 people in a dozen countries, half of them in Aceh province.

Landslide Risk is high in Big Sky Mountains of Montana.

2009-08-30T21:25:00.000-07:00

Recent studies conducted by geologists in Montana showed that some parts of the spectacular Big Sky mountains may be in danger. The problem is "the shale formations in many parts of Big Sky are susceptible to landslides, and many houses have been built in areas that could start moving if there’s a period of exceptionally wet weather," the NewWestDevelopment.net reports .

The weak shale formations of Big Sky create ripe conditions for landslides.

Big Sky lies within the Intermountain Seismic Belt, a zone with the high earthquake potential, and thus a high risk of sudden landslides. In 1959, an earthquake with a 7.5 magnitude struck part of Madison Valley, about 30 miles south of the Big Sky-Moonlight Basin area, triggering a landslide that killed 28 people.

Mudslides pose a threat to Stinnett Elementary School in south-east Kentucky.

2009-08-28T00:22:00.000-07:00

Days of heavy rain earlier this month led to mudslides that nearly missed several homes and the Stinnett Fire House. At present, at least nine more slides can still occur on the mountain behind Stinnett Elementary School.

Heavy rain about two weeks ago caused the slides, and local officials are hoping something is done before the next big storm.

A school superintendent in eastern Kentucky calls recent mudslides near an elementary school "worrisome." It might be a bigger problem for Stinnett Elementary School the next time it rains hard. Emergency management director James Couch suggested that "some old mining activity could have caused some of the run-off and the slipping as well."

Emergency crews are hoping for a solution from state and federal officials before the next storm. Superintendent Larry Sparks says he, along with other school officials plan to hike up the mountain behind the school Thursday to see the damage first hand.

Rockslide Closes Hotel in Yosemite National Park.

2009-08-27T06:58:00.000-07:00

A series of rockslides in Yosemite National Park forces the evacuation of about 300 guests from the historic Ahwahnee Hotel. Officials said the hotel would likely remain closed until Friday afternoon. Photo by the National Park Service. Officials still have no indications, of what may have caused the rockslides.

Park officials say there are no reports of any injuries, just a lot of scared and misplaced hotel guests. "The actual landslide felt like an earthquake, made the window buckle," said wintesses, who saw large boulders tumble on to cars at the hotel.

Geologists are monitoring the cliffs behind the Ahwahnee Hotel. In October of last year, parts of Curry Village were shut down, after rocks slid on to where nearly a thousand people were camping at the time. Geologists believe rain triggered that rockslide, which injured three people and damaged nearly a dozen cabins.

Landslide that caused tsunami in Lincoln County was recorded on video

2009-08-25T17:59:00.000-07:00

A landslide across Porcupine Bay in Lincoln County created huge waves in the Spokane River that hurt two children swimming in the water Tuesday afternoon. Authorities say around 1 p.m. Tuesday unstable land in Stevens County on the Spokane Indian Reservation gave way and rushed into the Spokane River across from Porcupine Bay. Docks, boats and other property along the Porcupine Bay shore were also damaged from the large waves and some logs were thrown onto the shore.

Camper Karin Mustard caught the last part of the landslide on home video. She said she thought the waves that came rushing in would "take out the whole campsite." The video can be watched here: http://www.krem.com/video/localnews-index.html?nvid=392361&shu=1

Donegal mudslide causes damage in Ireland.

2009-08-24T18:11:00.000-07:00

Just yesterday I wrote about the causes of landslides in Ireland. There is another example of this phenomenon. Look at how gentle the slope is.A view of mudslide north of Glencolmcille. It has cut off 20 families in a remote part of the Donegal Gaeltacht.Photograph: Jason McGarrigle.

The mudslide, up to 220m wide and 1.5m deep, cut off about 20 families in a remote part of the Co Donegal Gaeltacht 10km north of Glencolmcille. Donegal mayor Brendan Byrne said a problem for workers clearing the mud was that a channel through it was unlikely to be an efficient short-term solution because of the liquid nature of the debris.

Landslides in Ireland mostly caused by climate change and man’s activities, a study says.

2009-08-24T00:28:00.000-07:00

The third wet summer in succession sparks fears of landslides in Ireland, the Irish Examiner.com reports today. A study conducted by the Geological Survey of Ireland (GSI) shows that most of slides are caused by climate change and man’s activities, including wind farm construction.

Experts are predicting wetter winters, especially in the west, and drier summers, in the east. There will also be more intense downpours of rain and rising sea levels, leading to bigger waves crashing into soft coastlines, resulting in erosion and cliff collapses. Also, the vast amount of construction that took place during the economic boom has created more risks. Houses, other buildings and windfarms were erected in boggy areas, sometimes making land unstable and more prone to slippage when heavy rains came.

One of the most notable landslides to occur in recent times was at Pollatomish, Co Mayo, in 2003. It caused a lot of damage to property and wrecked several houses. Photo by the Geological Survey of Ireland.

More about landslide in Ireland can be found here: Maps highlight landslide risk areas

How to protect highway from earthquakes.

2009-08-23T18:43:00.000-07:00

Two weeks ago, a relatively strong earthquake hit Japan, causing some damage to the Tomei Expressway, a highway that connects two major cities in the country: Tokyo and Osaka. A few days later, I came across an interesting article published by The Yomiuri Shimbun that gives an account of the incident. It is called "Soil under expressway 'too weak".

According to the article, "the soil foundation of the Tomei Expressway, a part of which collapsed in Shizuoka Prefecture during a powerful earthquake, may lack sufficient reinforcement, according to Central Nippon Expressway Co. (NEXCO-Central)."

The shoulder of the 100-meter section of the expressway near the Makinohara Service Area collapsed when the earthquake jolted the soil, which had been loosened by heavy rain that fell Monday.

The Tomei Expressway, which opened in 1969, was designed to withstand strong earthquakes. According to NEXCO-Central, it was not expected that a section of the expressway would collapse in a quake registering a lower 6 on the Japanese seismic intensity scale of 7. NEXCO-Central said it had taken measures against heavy rains, such as planting trees and other vegetation, to prevent rain from soaking directly into the upper soil layers. The expectation was that this would prevent erosion.

But no measures were taken to reinforce the soil deeper in the foundation. "We thought even if rain soaked into the upper soil, the water wouldn't stay but flow deeper underground," a NEXCO-Central official said. The combination of a large quantity of water that was still in the soil and the lack of reinforcement is suspected to be the main cause of the collapse, observers said.

The company likely will be urged to take measures to improve the situation. Meanwhile, the quake warped a section of the rails of the Tokaido Shinkansen line, and normal services were restored on the line within two days. JR Tokai said large steel plates about 1 centimeter thick have been placed under the soil in the section where rails were laid over loose earth to stabilize the foundation. The company says reinforcement work carried out to protect against both heavy rains and earthquakes have cost the company more than 1 billion yen per kilometer.

It is interesting that the soil conditions under the expressway were almost the same as those under the JR Tokaido Shinkansen line. But Central Japan Railway Co. had reinforced the soil under its tracks against earthquakes through such measures as laying steel plates.

Fatal landslide at Portuguese beach.

2009-08-21T16:34:00.000-07:00

Part of a cliff collapsed and buried bathers at Maria Luisa beach in Albufeira on the Algarve coast, said Marques Pereira, the head of maritime facilities in Faro.　The section of beach under the cliff that collapsed had been cordoned off with warning signs pointing out the danger of a possible landslide.　"The sandstone of the cliff was pretty fragile and a risk of a landslide existed to the point that the maritime authority had placed warning signs," Pereira said.

General view of Maria Luisa beach where rescue workers are seen searching for survivors after part of a cliff collapsed and buried bathers in Albufeira on southern Portugal's Algarve coast Friday, Aug. 21 2009. The landslide killed one person and injured at least eight while two others are still missing(AP Photo/Luis Miguel Ferreira).

Rescue workers search for the missing beachgoers after a rockslide at Maria Luisa beach in the southern Portugal province of Algarve August 21, 2009. REUTERS/Carlos Brito (PORTUGAL DISASTER) .

Massive landslide kills seven in Siliguri, India.

2009-08-16T17:59:00.000-07:00

Seven people were killed and many others injured in a series of landslides in Darjeeling. A massive landslide also blocked the National Highway No.55 leading to Darjeeling, as huge boulders rolled down the hill slopes, cutting off the road and a rail track of the Darjeeling Himalayan Railways, a world heritage site.

Local residents walk over the debris caused by a landslide along the national highway after heavy rains at Paglajora village, about 28 km (17 miles) north of the eastern Indian city of Siliguri August 16, 2009. The weather office has ruled out an early withdrawal for this year's monsoon which has still one and half months to complete its full journey.REUTERS/Rupak De Chowdhuri (INDIA SOCIETY ENVIRONMENT).

Landslide kills 11 in Zhejiang province of China.

2009-08-15T02:54:00.000-07:00

Eleven bodies were recovered and two injured people were rescued from the rubble of a rainstorm-triggered landslide in East China's Zhejiang province, the local government said Friday afternoon. The landslide occurred at around 11:30 pm Thursday in Qingliangfeng town after two hours of downpour with a precipitation of 88 mm. It buried a three-storey residential building with 13 people inside.

Excavators are seen digging through the rubble of a landslide in Lin'an city, East China's Zhejiang province, August 14, 2009. The landslide, believed to be triggered by a heavy downpour, left 11 dead and 2 injured.

Submarine landslides caused by Typhoon Morakot slow down Internet in Asia.

2009-08-13T18:35:00.000-07:00

Deep sea landslides caused by Typhoon Morakot severed at least three undersea fiber-optic telecommunications cables and disrupted three others, causing Internet service disruptions in parts of Asia. Straits Times reports that some Singapore Internet users may be experiencing slowdowns on the Information Superhighway, especially when trying to access websites hosted in the United States and Taiwan. The last time a major outage happened was in December 2006, when quakes off Taiwan severed several cables at once, causing the Net to go down.

Here are some pictures of catastrophic landslides/mudflows triggered by Typhoon Morakot.

An aerial photograph shows the landslide affected area after Typhoon Morakot swept Kaohsiung county in southern Taiwan August 13, 2009.REUTERS/Su Sheng-bin/Pool (TAIWAN DISASTER ENVIRONMENT).
An aerial photograph shows the flooded area after Typhoon Morakot swept through, Kaohsiung county, southern Taiwan August 13, 2009. REUTERS/Su Sheng-bin/Pool (TAIWAN DISASTER ENVIRONMENT).
An aerial photograph shows a Buddha statue beside a landslide affected area after Typhoon Morakot swept through Kaohsiung county in southern Taiwan August 13, 2009.REUTERS/Su Sheng-bin/Pool (TAIWAN DISASTER ENVIRONMENT IMAGES OF THE DAY).

Massive landslide crushed several houses in China.

2009-08-11T17:37:00.000-07:00

A massive landslide triggered by torrential rain from Typhoon Morakot toppled seven houses in a town in eastern China, killing two people and injuring four.

People look at the remains of seven houses which were crushed by a landslide triggered by Typhoon Morakot in Taishun county in east China's Zhejiang province Tuesday Aug. 11, 2009.(AP Photo) CHINA OUT.

The landslide destroyed at least six four-story apartment buildings at the foot of a mountain at 10:30 p.m. local time, Xinhua said. The disaster was triggered by pounding rain brought by Typhoon Morakot.

Typhoon Morakot, which means emerald in Thai, forced the evacuation of 1.4 million people in eastern China. It landed Sunday in Fujian province after slamming Taiwan over the weekend with as much as 80 inches of rain.

Pictures of mudslide that buried 600 villagers in Taiwan. Update.

2009-08-11T07:56:00.000-07:00

A photograph from the Taiwan Military News Agency shows an aerial view of the flooded village of Hsiao Lin, southern Taiwan's Kaohsiung county, China, August 10, 2009.

A photograph from the Taiwan Military News Agency shows a soldier sifting through debris caused by Typhoon Morakot in southern Taiwan's Kaohsiung county August 10, 2009. Rescue squads aboard helicopters had saved only 45 people from Hsiao Lin, a village of 1,000 in southern Taiwan.
A road is damaged by a mudslide caused by typhoon Morakot in Pingtung County, southern Taiwan August 10, 2009. REUTERS/Stringer (TAIWAN DISASTER ENVIRONMENT).

A handout photograph from the Taiwan Military News Agency shows a storm-damaged bridge near Hsiao Lin, southern Taiwan's Kaohsiung county, China, August 10, 2009.

A powerful earthquake shuts down nuclear reactors in Japan.

2009-08-10T22:19:00.000-07:00

A powerful earthquake hit Tokyo and nearby areas early in the morning on Tuesday, halting trains and forcing two nuclear reactors to shut down for safety checks. More than 30 people suffered minor injuries. Two reactors at the Hamaoka nuclear power plant were temporarily halted for safety checks. The quake also triggered several shallow landslides causing some damage to highways. Photos by Daily Yomiuri.

A magnitude 6.9 quake rattled the same region on Sunday as well, but no damage was reported. The U.S. Geological Survey measured its magnitude as 7.1.
Japan is one of the world's most earthquake-prone countries, and experts believe Tokyo has a 90 percent chance of being hit by a major quake over the next 50 years.

Tropical storm Etau hits Japan causing great damage.

2009-08-10T22:03:00.000-07:00

A tropical storm triggered mudslides and floods in Japan, killing at least 10 people, local officials said on Monday, bringing weather-related deaths in northeast Asia to at least 34 people in the past few days.

Tropical storm Etau is now hitting Japan after typhoon Morakot battered the Philippines, Taiwan and China, killing at least 24 and damaging houses and farms.

At least nine people were killed and eight more were missing in Hyogo, western Japan, a police official said. He could not confirm how the victims had died. It was forecast to bring wind gusts to 126 kph (78 mph), heavy rain and high seas.

Hundreds missing in landslide as Typhoon Morakot hits Taiwan.

2009-08-10T06:26:00.000-07:00

Fears were growing for 1,000 villagers in southern Taiwan who were declared 'missing' on Monday after a typhoon resulted in a landslide that buried up to 200 houses under a wall of mud.

Updated map showing the areas most affected by Typhoon Morakot. At least 31 people were known to have died and scores more were reported missing after typhoons battered East Asia, as parts of the region experienced their worst weather in half a century.

Typhoon Morakot dumped up to 80 inches (two meters) of rain on some communities over the weekend before moving on to China, where it forced the evacuation of nearly 1 million people along the east coast. Earlier it had struck the Philippines, leaving at least 22 dead. It has now been downgraded to a tropical storm.In this photo released by the Pingtung government on Monday, Aug. 10, 2009, vast farmland flooded by typhoon Morakot and a swollen river are seen in Chiatung, southern Taiwan.

A massive landslide is seen across a mountain road in Pingtung county, southern Taiwan, Monday, Aug. 10, 2009. An estimated 400 Taiwanese are unaccounted for after the landslide spawned by Typhoon Morakot struck their isolated mountain village of Hsiaolin, a police official said Monday, and a newspaper quoted a resident as saying as many as 600 were buried.

A hotel building leans before falling in a heavily flooded river after Typhoon Morakot hit Taitung county, Taiwan, Sunday, Aug. 9, 2009. The six-story hotel collapsed and plunged into a river Sunday morning after flood waters eroded its base, but all 300 people in the hotel were evacuated and uninjured, officials said.(AP Photo).

Catastrophic landslide kills 46 people in India.

2009-08-09T20:45:00.001-07:00

At least forty-six people were killed in a landslide triggered by heavy rains in the northern Indian state of Uttarakhand, police said on Sunday.

Rescue workers and volunteers stand amid the debris after a landslide at Pithoragarh district in Uttarakhand state, India, Saturday, Aug. 8, 2009. Landslides triggered by heavy rains killed at least 43 people in three remote villages in northern India, a police official said Sunday.(AP Photo/Bijendra Lunthi).

Three villages in the hilly Pithoragarh district were swept away in the landslide after a cloudburst on Saturday, local police official M.S. Sathnam said. Poor weather hampered the rescue operation.

According to an official report, about 100 villages in Uttarakhand are prone to natural disasters.

Deadly landslide in China raises more fear.

2009-08-09T20:33:00.000-07:00

A massive landslide that occurred last Thursday in Southwest China's Sichuan province has forced the evacuation of some 10,000 residents along the Dadu River. The debris formed a 250-m-long blockage on the Dadu River, killing two people, injuring 18, inundating eight farmhouses and destroying 10 vehicles.

Most of the dead and missing were passengers who had taken the Beijing-Panzhihua railway to the Wusihe railway station where they transferred to buses which were later caught in the landslide.

The debris formed a 250-m-long blockage on the Dadu River, resulting in the rise of the water level upstream and endangering people there. Explosives experts had planned to blast off the debris into the river at 5 pm on Sunday. But they postponed the plan because a large rock on the mountain opposite the debris was likely to fall into the river at any time.

Landslide destroys hotel in Taiwan

2009-08-09T17:59:00.000-07:00

A six-story hotel in Jhihben township in the eastern county of Taitung toppled into a river around noon Sunday in a landslide caused by Typhoon Morakot's torrential rains over the weekend.

Hotel Jinshuai tilted on its foundations at an angle of 20 degrees Sunday morning after flooding and a landslide washed away a 200-meter area near the building. It collapsed around noon. All the guests and staff at the hotel had been evacuated to safety before it toppled.
Jinshuai was one of the scores of hotels in Jhihben township, which nestles at the foot of a mountain and is known for its hotsprings. Some 400 tourists have been stranded in Jhihben, according to reports at noon Sunday.

Fatal landslide in Kangding, China.

2009-07-23T23:27:00.000-07:00

Four construction workers died and more than 50 were missing on Thursday after a landslide destroyed a dam project in Sichuan Province, in the latest of a series of disasters caused by heavy rains in southwest China. The downpours set off a landslide at the Changheba hydropower plant in Kangding, temporarily blocking a river, the Xinhua news agency said, citing the ministry of civil affairs. The rapid rivers of Sichuan are packed with hydropower dams.

Rescuers search for buried victims after a landslide in Kangding in southwest China's Sichuan province, Friday, July 24, 2009. The landslide triggered by heavy rain hit a county in southwestern China's Sichuan province early Thursday, killing at least four people and leaving 50 others missing, state media said.(AP Photo).

Mudslide kills four people in Japan.

2009-07-21T04:16:00.000-07:00

Mudslides sparked by torrential rains have killed at least four people and left five others missing in the western Japanese prefecture of Yamaguchi on Tuesday, media reports say. The disaster was caused by heavy rainfall (about 300 mm) that hit the area for the past few days. A nursing home for the elderly in Hofu city was hit by a landslide, prompting the military to send a rescue unit there, Jiji and Kyodo news agencies said. About 10 cars were also seen buried in one mudslide.

What caused the Nachterstedt landslide in Germany?

2009-07-20T23:33:00.000-07:00

Rescue workers in the state of Saxony-Anhalt have given up searching for three missing victims of Saturday's landslide, saying there's no hope of finding them alive. The victims were swept to their deaths at 4:40 a.m. on Saturday morning when their homes suddenly collapsed into a man-made lake on the site of a former open-cast mine in Nachterstedt, around 170 kilometers south-west of Berlin. At present, the village remains sealed-off, as further cracks in the ground were discovered, raising fears of a further collapse.

Aerial view of the disaster area. The Concordia coal mine had advanced to 120 meters from the nearest home since it was closed in 1991 and flooded.

As for the mechanism of the slide, experts suggested that a rise in ground-water levels at the site may have caused the disaster. Another possible cause is heavy overnight rain, according to a spokesman of the company (LMBV) formerly in charge of the mine.

A catastrophic landslide in Germany, three people missing.

2009-07-18T17:30:00.000-07:00

Three residents were missing in the eastern German village of Nachterstedt after their lakeside home and another building suddenly collapsed early Saturday into the water. A 350-metre stretch of shoreline gave the way next to an old open-cast coalmine converted to a lake, about 170 kilometres south-west of Berlin.

The ruin of a residential house, top, center, destroyed street in Nachterstedt, Germany, Saturday, July 18, 2009. (AP Photo/Jens Meyer). The destroyed building, half of a pair of attached houses, slipped down about 100 yards (100 meters) to nearby Lake Concordia and was buried under mud and water.

REUTERS/Handout/Gemeindeverwaltung Nachterstedt (GERMANY DISASTER ENVIRONMENT) FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. A crumbling house sits on the edge of a drop following a landslide in the village of Nachterstedt, July 18, 2009.

Massive landslide in New Zealand following the M=7.8 earthquake.

2009-07-17T21:58:00.000-07:00

A massive landslide was triggered by the strong earthquake (M=7.8) that hit New Zealand on Wednesday.

A landslide is seen near Lake Purser, south of Dusky Sound on the west coast of New Zealand's South Island Thursday, July 16, 2009 after a 7.8-magnitude earthquake hit the area Wednesday. The earthquake generated a small tsunami but no injuries or major damage were reported.(AP Photo/New Zealand Herald, Simon Cox).

The quake, the largest recorded in New Zealand in 80 years, was centered off the west coast of the South Island at a depth of only 7.5 miles (12 kilometers). No major damage has been found in the sparsely populated Fiordland on the west coast of the South Island. Martin Reyners, principal scientist for GNS Sciences, said a shallow temblor of such magnitude would typically cause widespread damage and loss of life. Wednesday's quake, however, occurred in "soft rocks" between two tectonic plates, muffling its power. Reyners said the rocks lurched rather than snapped, causing a low-frequency rolling rather than the high-frequency waves which damage buildings. "It's a good reminder to New Zealanders that we have had earthquakes this size in the past ... and sooner or later we will have one in a more populated area," he said.

Logan Canal was doomed to burst due to poor maintenance.

2009-07-13T05:25:00.000-07:00

It was just a matter of time when local and state authorities left the job of inspecting the canal to the group of water shareholders who privately owns it. And there was no government entity set up to scrutinize those checks. Residents believe that poor maintenance led to the the rupture of the canal, sending water and mud straight into homes near 900 East and Canyon Road, an area known as the Island. Photo taken 10 minuets before second collapse. - Photo by Barney Auman.
Where the canal broke. - Photo by Dustin Auman.

Colleen Gnehm, water commissioner of the Logan River, which feeds several local canals, noted the canal was inspected by the group that owns it just two weeks before the break. But although she expressed confidence in the way those inspections are carried out, Gnehm conceded that no one in government was exercising oversight or enforcing standards. Workers and Logan officials survey the home at 915 E. Canyon Road, Logan on Sunday. (Scott Sommerdorf / The Salt Lake Tribune).

After the water was drained following Saturday's disaster, several areas below the water line were revealed where concrete is eroding into rubble. Vertical and diagonal cracks also line some sections. In some areas the ditch's walls are bulging under the weight of the northern hillside. Emergency officials had faulted the natural springs that run under the canal. Those springs may have weakened the ground, causing an unavoidable collapse.

Canal breaks in Logan, Utah, causing great damage.

2009-07-11T21:49:00.000-07:00

A canal adjacent to the Logan River broke at around 11:30 Saturday morning, sending water and mud into houses below. The mudslide ripped through one home, and four others are still at risk, officials said. Fifteen homes have been evacuated, and several others have been damaged by water and mud.

Emergency crews work at the site of a mudslide in Logan on Saturday. An irrigation canal ruptured, sending water and mud into homes in the area of 900 E. Canyon Road. One home was destroyed and others were damaged. A dozen homes have been evacuated. (Mike Terry, Deseret News).

The canal was shut off to try and stop the flow of mud and water. It was running at full capacity when the slide happened. The canal is named the Logan-Hyde Park Smithfield Canal, and is made of concrete slabs where the slide happened. Those concrete walls are now gone, along with a lot of the dirt and rocks that used to line the canal.

The U.S. Geological Service is calling the scene near the slide moderately safe, but surveyors are evaluating the nearby land to ensure the freeway above the canal and surrounding homes are structurally sound.

Emergency crews have closed off four blocks surrounding the landslide. Gas leaks caused by the slide were quickly contained, officials said. About 600 homes in the area were temporarily without power, though it has been restored for all but the area of the landslide.
It is not clear yet what caused the break. Several neighbors said they had noticed cracks in the canal earlier in the week and that water had been leaking onto Canyon Road. Some said they had complained to Logan's public works department about the problems. Mark Nielsen, director of public works for Logan, said landslides have been common in the area for the past 150 years, yet crews work to keep the canal system in as good of condition as possible.

A Powerful Earthquake Rocks China, injuring hundreds and collapsing 10,000 homes.

2009-07-11T00:35:00.000-07:00

A powerful earthquake rocked southwest China on July 9, 2009, injuring at least 336 people and collapsing 10,000 homes, state media reported. The magnitude-6.0 temblor, centered in Yunnan province's Yao'an county, damaged another 30,000 homes, the Xinhua News Agency said.

This image, made from data collected by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite, shows the topography of the earthquake region.

In this photo released by China's Xinhua News Agency, a damaged house is seen in Guantun Village in Guantun Town of Yao'an County, Chuxiong Yi Autonomous Prefecture in southwest China's Yunnan Province Friday, July 10, 2009.
A man stands on the debris of a collapsed house in Yao'an County, Chuxiong Yi Autonomous Prefecture in southwest China's Yunnan Province early Friday July 10, 2009.

Yunnan is a quake-prone, mountainous region that lies on China's southern border with Thailand and Burma. Like all of southern China, the region is prone to earthquakes because of the ongoing collision between the Indian plate and the Asian plate. India is moving north-northeast, putting pressure on the Asian plate. The pressure causes the land to fold, creating mountains. The pressure also leads to faults (cracks or weak spots) in the rocks in Earth’s crust. When the land moves to accommodate the pressure, the Earth shakes. The whole of southern China experiences earthquakes related to tectonic motion. The July 9, 2009, earthquake occurred nearly 700 kilometers from the devastating 2008 earthquake in Sichuan province that killed nearly 87,000 people.

An earthquake triggers a rockslide in Colorado, USA. News in Pictures.

2009-07-09T23:40:00.000-07:00

The 2.6 shiver on the Richter scale, as measured by the National Earthquake Information Center in Golden, triggered a rockslide in the Palisade area of the Bookcliffs, adjacent to Mount Garfield, Colorado, USA. "We are calling this an earthquake causing the landslide,” said Richard Buckmaster, geophysicist for the earthquake center. “Earthquakes of this magnitude are common and can happen anywhere in the world. It is not completely unheard of.”

Paul Ross of Palisade captured this spectacular scene early Thursday of a rock slide set off by a small earthquake of a magnitude of 2.6, according to the U.S. Geological Survey. A massive dust cloud obscures the slide which occurred near Mount Garfield and the Bookcliffs. The USGS reports the earthquake happened at 5:44 a.m.; its epicenter 6 miles south of Palisade. Photo by Paul Ross.

Catastrophic landslide kills 24 in Myanmar. News in Pictures.

2009-07-09T06:29:00.000-07:00

A landslide caused by heavy rain killed 24 migrant mineworkers at Lonkhin near Phakant, in Myanmar’s northernmost state of Kachin. The accident happened during a period of severe wet weather from July 4-6, an official from the state’s police force said. –Reuters Photo.

Illegal constructions may be a cause of recent landslides in Darjeeling, India!?

2009-07-09T06:01:00.000-07:00

The massive construction of buildings, a majority of them illegal, has led to degradation of soil texture in the Darjeeling Hills area of West Bengal, making the place vulnerable to landslides, according to DailyIndia.com. This landslide occurred in the TungSung of Darjeeling town, which is a densely populated area located along the eastern spur of the Jalpahar. From DarjeelingTimes.com.

"For the since last 100 years, Darjeeling is witnessing an rapid increase in population. This migration of population has led to an increase in unauthorised constructions. This coupled with the lack of a proper drainage system in the Darjeeling Hills culminated in the recent catastrophic landslides," said Subhir Sarkar, a geologist.

The government seems to understand the problem. Ashok Narayan Bhattacharya, the State Minister for Urban Development and Municipal Affairs, said that "the state Government has asked the local civic body to take active measures against it."

Why are there so many landslides in Darjeeling, India?

Landslides: A look from Space.

2009-07-04T07:03:00.000-07:00

The American space agency and Japan's Ministry of Economy, Trade and Industry have released a new digital topographic map of Earth that accurately portrays more of our planet than ever before. This is the most complete, consistent global digital elevation data yet made available to the world," said Woody Turner, a program scientist at NASA headquarters in Washington.

The map covers more than 99 percent of Earth's land mass from north of the Arctic Circle to south of the Antarctic Circle.

This view of Death Valley, California, was created by draping an Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) simulated natural color image over digital topography from the ASTER Global Digital Elevation Model (GDEM) data set.

It looks like this map might be very helpful to study landslides that occur in remote areas. Also, it will be a useful tool for landslide hazard and risk assessment. There are some images of catastrophic landslides in China and Guatemala that were released by NASA in the past few months. On June 5, 2009, a mountainside collapsed in the Chongqing region of southern China. The landslide dropped some 12 million cubic meters (420 million cubic feet) onto several homes and an iron ore mine, trapping dozens of people. According to a June 18 report from Xinhua News Agency, 64 people remained missing.
Related articles:

Search for missing miners continues despite the looming threat of new landslides.

The cause of catastrophic landslide at a Chinese mine is negligence. Again?!

On January 4, 2009, a mountainside in northern Guatemala suddenly collapsed, sending thousands of tons of rock and debris downhill and burying a nearby road. The event occurred in the state of Alta Verapaz, some 200 kilometers (124 miles) north of Guatemala’s capital city.

What triggered the Landslide in Guatemala : Geological fault or Road Construction?

Human Activities Triggered the Guatemalan Landslide?!

Why do people live on dangerous steep slopes in Guatemala?

Heavy rainfall cuts off Darjeeling and Sikkim from the rest of India. News in Pictures.

2009-07-04T06:50:00.000-07:00

Sikkim and major parts of Darjeeling were cut off from the rest of the country following a series of landslides triggered by heavy rainfall. The slides occurred at Rohini, Sevok checkpost, Sevok Kalibari, Kalijhora, Andheri chowk and places near Kurseong breaching links of NH 33 among northern parts of Bengal, Assam and other Northeast states. AP Photo.

The landslide problem in Maine, USA, might be more serious than it seems.

2009-07-03T08:01:00.000-07:00

The Maine Geological Survey issued the warning after a landslide occurred June 25, on the shore of the Penobscot River in Stockton Springs, a town about 180 miles northeast of Boston. The top of the bluff appears to have receded about 30 feet, and a nearby railroad track southwest of the area also comes close to the bluff edge and could be threatened by a similar landslide, MGS marine geologist Stephen Dickson said.

At least two camps on Schooner Drive in Stockton Springs are under threat following a coastal landslide on June 25. (Photo by Tina Shute).

There seem to be two major causes of the slide: geological settings and a high ground water table. "Recent heavy rains through the month of June have contributed to high water tables and saturated muddy coastal bluffs," Dickson said. Although no damage was reported, the problem seems to be more serious than it looks at first. A detailed study by the Maine Geological Survey shows that there are other natural slopes along the banks of rivers and streams where the mud thickness is 20 feet or more and saturated by a high water table.

This map, prepared by the Maine Geological Survey, indicates areas of potential landslide hazard along Fort Point Cove in Stockton Springs. The green areas indicate low coastal bluffs, which MGS reports are generally "not at risk of failing in the form of a landslide." The yellow areas indicate potential landslide areas, which have "not had field investigations that are necessary to evaluate the risk of a landslide," but which are similar in nature to other areas that have experienced landslides, according to MGS. The approximate area of the landslide on June 25 is indicated by the light blue circle. (Maine Geological Survey Web site).

Central China is on the orange alert as rainstorm destroys 3800 homes. News in Pictures.

2009-07-03T06:58:00.000-07:00

Severe storm with an average rainfall of 100 mm has caused significant economic loss (the damage is estimated to be about 1.48 billion U.S. dollars) in central China's Hunan Province. The rainstorm has already destroyed 3,800 homes, 800 embankments and almost 40,000 hectares of cropland.

A massive landslide was triggered in Shiniu Village, Shuangfeng County, killing a family of four and leaving another villager missing.

About landslides, slope development and deforestation in Malaysia.

2009-06-24T18:41:00.000-07:00

Professor Roslan Zainal Abidin, the director of the International Research Centre on Disaster Prevention at University Teknologi Mara in Shah Alam, recently spoke on the topic of landslides in Bukit Larut, Malaysia.

Photos from http://taipingtalk.com/bukitlarut/

The famous hill station has been identified by an expert as home to the country's 14 most critical landslide areas. According to Professor Abidin, there are two major factors leading to landslides: "the area's rainfall pattern and soil texture." His study shows that the hills are mostly made up of sand and silt, and "water would go through it easily and wash the soil away."

While the soil texture helps to identify the hazard zones, the rainfall pattern indicates the time when a landslide might occur. For Bukit Larut, the most dangerous month is November, followed by March and September. August seems to be "the safest". "In Malaysia, three to seven days of continuous rainfall on a sloping area can trigger a landslide," says Roslan.

It is interesting what Professor Abidin thinks about deforestation and slope development, two issues that have sparked off a lot of debates recently.A landslide that occurred at a timber camp near Medamit in 2008. Deforestation was cited as one of the causes.

"The risk is there, but because the area is quite heavily forested, you rarely see landslide tragedies. If you don't touch the hill, landslides will happen naturally, but slowly. If you disturb the slopes, you speed up the process."

The 2008 Bukit Antarabangsa landslide was blamed for poor maintenance of the slope.

Despite the danger, Roslan says development is possible, provided the risk is known and precaution taken. "But the problem is when the project is nicely done up but there is zero maintenance. There will then be no proper drainage, no periodic checks."

Related articles:

What Causes Landslides in Malaysia?

Hillside Projects in Malaysia can go on until next Landslide?!

Does logging cause landslides in Malaysia?

Another Landslide in Malaysia Claims Lives

Why are there so many landslides in Malaysia?

Another Landslide Threat in Malaysia. How to Prevent It?

Is the Hong Kong's Slope Safety System the Right Choice for Malaysia?

Bukit Antarabangsa landslide: Heavy Rainfall or Mismanagement?

Malaysia: Hillside developments banned again?! From Highland Towers Collapse, 1993, to Bukit Antarabangsa Landslide, 2008.

Landslide caused by human activity kills 4 people in Malaysia

Danger looms when there's too much rain.

How to protect your home from mudslide. A manual from Draper.

2009-06-21T18:29:00.000-07:00

What do you need to do when heavy rains are about to trigger a mudslide that would flood your house? Residents of Draper, Utah, seem to know the answer. After being hit by mudslides last week, they are now ready to take on the next punch Mother Nature throws their way. What have they done?

Volunteers filled sandbags, helping efforts to stop storm runoff from flooding homes along Bear Mountain Drive on Saturday. (Trent Nelson / The Salt Lake Tribune)

They worked all together to dig a trench to divert water from going into their homes. Then they filled sandbags and placed them in the trench.

Finally, the trench was covered with plastic to protect it from rain water run off.
These measures are supposed to save your home from next mudslide. And one more thing, to pull it off, you need to have nice neighbours who are willing to help you.

A huge mudslide in Draper, USA, despite preventive measures.

Fifteen villages in the Philippines are in imminent danger due to landslides.

2009-06-21T06:10:00.000-07:00

The Mines and Geosciences Bureau (MGB) of the Region 7 office of Cebu City has released a statement that "based on the assessment of the latest geo-hazard mapping which covered the 26 mountain villages in this city, 15 of it have high susceptibility to landslides, eight are moderately susceptible and three have low landslides susceptibility." A list of villages, which were identified as highly landslide prone areas, can be found here. An official of the MGB 7 has also warned residents that destructive landslide can possibly occur any time soon, as the rainy season started, and "soil is being saturated."

The Guinsaugon landslide, Southern Leyte, the most destructive landslide in the history of the Philippines. Caused by heavy rains, it killed more than 1000 people in February 2006.

Landslides in Compostela Valley, Philippines: Rainfall and Illegal Logging again?

Logging, Landslides and The Philippines.

Landslides in the Philippines. Logging and La Nina.

A huge mudslide in Draper, USA, despite preventive measures.

2009-06-18T18:59:00.000-07:00

According to ksl.com, a mudslide hit three homes Wednesday night in the Draper area, Utah, following heavy rains. Part of a mountainside slid down, slamming into the homes and caking two basements and a garage in debris and mud. All photos from ksl.com.
The same area was burned by a huge wildfire in August 2008, making it an area of concern for slides. Residents say that "wildfire last year had uprooted the plants and trees that could have kept the mud at bay." Instead, the fire practically prepped the mountainside for the mudslide that came rushing through Draper's Bear Ridge Cove, causing damage to homes and covering the streets with mud.
Officials from the U.S. Forest Service and Draper City flew over the area to assess the potential for more trouble. They say straw mulch and debris fences installed after last summer's fire did the job. There was just too much rain. "Not necessarily on a fire [scar], but on any place that gets that amount of rain in that short period of time is going to have problems with flooding," said Paul Flood, soil scientist with the U.S. Forest Service.

Mudslides after Wildfires and Preventive Measures.

Wildfire in California, Mudslides Next?

Mudslides besiege a small community in Newfoundland, Canada.

Cultural heritage in Europe may be in danger, studies say.

2009-06-17T18:35:00.000-07:00

It may come as surprise that many historical places in Europe are currently in a great danger because of landslides. Most of ancient settlements were built on steep slopes or river banks, and over a period of time the stability of such places was undermined by weathering. Studies show that almost each country in Europe has this problem. Here are a few examples.

1. The abandoned town of Craco, Basilicata, Italy.
A view of the abandoned town of Craco, Basilicata, Italy. Photo by L. Coppola. From Bromhead et al. 2006.
Bromhead et al. (2006) writes that "the town of Craco, in Basilicata, southern Italy, is one of many examples where landslide movements have caused the entire population to abandon their homes en masse, and remains to this day a deserted monument to a devastated community."

2. The Calomini hermitage in the Garfagnana area, Serchio Valley, Tuscany, Italy.

The Calomini hermitage and the rock wall above. From Avanzi et al. 2006.

Avanzi et al. (2006) notes that "the Calomini hermitage is situated on a steep slope, surmounted by an 80- to 130-m-high hanging rock wall. The hermitage has been a pilgrimage place since the Middle Ages,when the first community of monks settled on this site due to plentiful local water supply.The architectural complex, already existing in the tenth century, is partly built into the rock mass. At present, the safety of the area is threatened by rock falls, which come from the calcareous rock slope above."

3. Spis Castle, Slovakia.

Vlcko (2004) points out that "Spis Castle was built on a travertine mound overlying soft Paleogene rocks. Lateral spreading resulting from the subsidence of strong upper travertine into soft claystone strata has fractured and separated the castle rock into several cliffs. The differential movement of individual cliff faces is the primary influence on the stability of the monument."

4. The Castle of Platamon, Greece.

A view of the Castle of Platamon in Greece. From Anthopoulou et al. 2006.

The castle of Platamon was built on Neogene marl during the period 1204–1222 A.D. In the past few decades, the stability of the slope has been severely affected by erosion.

References:

E. N. Bromhead, P. Canuti, M.-L. Ibsen. Landslides and cultural heritage. Landslides (2006) 3:273–274.

Giacomo D’Amato Avanzi, Daria Marchetti, Alberto Puccinelli. Cultural heritage and geological hazards: the case of the Calomini hermitage in Tuscany (Italy). Landslides (2006) 3:331–340.

Jan Vlcko. Extremely slow slope movements influencing the stability of Spis Castle, UNESCO site. Landslides (2004) 1:67–71.

B. Anthopoulou, A. Panagopoulos, Th. Karyotis. The impact of land degradation on landscape in Northern Greece. Landslides (2006) 3:289–294.

Search for missing miners continues despite the looming threat of new landslides.

2009-06-16T07:00:00.000-07:00

Despite the fact that ten small slides have already hit the landslide site in Wulong County, Chongqing Municipality, China, about 3,000 rescuers aided by heavy machinery continue their search for 64 missing for the 10th day. The rescuers have brought the risk of a barrier lake under control, as the level of the water dropped 10 meters below the top of a temporary embankment, thanks to drainage work.Heavy machinery works at the landslide site in Wulong County, southwest China's Chongqing Municipality, June 15, 2009. The rescue headquarters said that seven potential geological disaster spots were located that may not only affect the rescue work but also threat the lives of over 3,000 rescuers at the landslide site.(Xinhua/Xu Xuzhong).

A geologist with the rescue headquarters said that cracks with a span of eight to ten meters and up to 30 meters deep have appeared on the landslide-hit hills. He said under the threat of secondary disasters, the search for the missing may be suspended. Nevertheless, Bo Xilai, secretary of the Chongqing Municipal Committee of the Communist Party of China, has ordered rescuers to make their utmost efforts to save lives and retrieve the bodies.

Rescuers have not yet found the mine entrance, which was buried deep under landslide rubble.

The cause of catastrophic landslide at a Chinese mine is negligence. Again?!

Landslide at a Chinese mine buries 106, more damage expected.

Are China's mines still the most dangerous in the world?

Mining and Landslides: What went wrong in China?

Three Gorges in China and Landslides.

First wireless landslide detection system developed in India, but will it work?

2009-06-14T23:44:00.000-07:00

Good news came from India, where scientists from the Amrita Vishwa Vidyapeetham have developed India’s first wireless sensor network system for landslide detection under a Rs 3.5 million Euro research project funded by the European Commission. The research project called ‘WINSOC’ (Wireless Sensor Network with Self Organisation Capabilities for Critical and Emergency Application) consisted of a consortium of 11 partners from eight countries. The scientists have deployed a number of wireless sensors in and around Antonyiar colony in Munnar where five people lost their lives in the landslide that happened in July 2005. The sensors are buried a couple of metres into the soil and can measure the moisture content, pressure and vibration of the earth and several other geological parameters.

The new wireless network will inform the local authorities 24 hours before a landslide actually happens. The Chanmari landslide. From Bhasin et al. (2002).

Wireless sensors have already been used in Japan to predict the occurrence of shallow landslides. It is interesting that the major advantage of them is surprisingly low cost. According to Uchimura and colleagues, who used such sensors for natural and artificial slopes, there are several problems that need to be solved before the effective early warning system can be developed. For example, their study showed that moisture content is not a reliable parameter, and it should be used together with inclinometers or extensometers.

References:

Uchimura, T., Towhata, I., Wang, L., and Seko, I. (2008). Simple and low-cost wireless monitoring units for slope failure. The first world landslide forum, Japan, 611-614.

Rajinder Bhasin, Eystein Grimstad, Jan Otto Larsen, Ashok K. Dhawan, Rajbal Singh, S.K. Verma, K. Venkatachalam. Landslide hazards and mitigation measures at Gangtok,Sikkim Himalaya. Engineering Geology 64 (2002) 351–368.

Landslides in Sikkim, India: Types, Causes, Mitigation.

Why are there so many landslides in Darjeeling, India?

Mudslides besiege a small community in Newfoundland, Canada.

2009-06-14T03:51:00.000-07:00

It might be six or seven months before five families from the western Newfoundland community of Trout River will be able to return to their homes after a mudslide came close to burying the buildings.

A mudslide on Saturday dislodged a home in the western Newfoundland community of Trout River. (Doug Greer/CBC).

For the second time this month, tonnes of mud slid down a slope in Trout River. (Doug Greer/CBC).

This week, heavy rain caused another slide in the area, pushing a house into the middle of a street. It was one of the five homes evacuated after a smaller mudslide came close to engulfing several houses last Saturday.

Part of a hill in Trout River, in Gros Morne National Park, gave way a week ago. (David Burke/CBC).

Tonnes of mud came close enough to five Trout River homes to put them at risk. (David Burke/CBC).

Municipal engineers believe it could take a long time before the affected families are allowed to return to their homes.

Landslides in Daniel’s Harbour are caused by sensitive clay?!

Climate change may cause more landslides in Central America and Asia, a U.N.-backed study says.

2009-06-12T05:25:00.000-07:00

Climate change will aggravate natural disasters and people in developing nations such as Dominica, Vanuatu, Myanmar and Guatemala are most at risk, a U.N.-backed study showed on Thursday. The Global Assessment Report on Disaster Risk Reduction urges governments to invest hundreds of billions of dollars to curb mounting impacts of hazards such as cyclones, floods, droughts, landslides, earthquakes and tsunamis. "Climate change will magnify the uneven distribution of risk, skewing disaster impacts even further towards poor communities in developing countries," Andrew Maskrey, lead author of the report, said.

Rainfall-induced landslide in Guatemala. Will there be more of this type?

According to the report, the safest places to avoid natural disasters include Saudi Arabia, Oman, Belgium and Britain.

The largest landslide stabilization project in California.

2009-06-12T00:26:00.000-07:00

We already know that Japanese engineers are good at stabilizing slopes affected by landslides. Lets see how they do it across the ocean. The example I found seems to be one of the largest landslide stabilization projects in California, USA. It is described in detail by Salter and colleagues (2007) (see the reference below). The name of the place is "The Point", it is a 14.5-acre commercial development in the Rancho Bernardo area of the City of San Diego.

What was the problem?

In 2004, extensive deformations of an existing Keystone™ wall and cracking adjacent to the commercial structures occurred, indicating substantial landslide activity within the property. Field investigation revealed that the project site was underlain by ancient landslides and other weak soils that were not removed or stabilized during earlier development.

Mitigation works. Slope stabilization included permanent ground anchors and a series of buried structural grade beams. Just to show the scale of this project, it included 1,160 permanent ground anchors; 4,500 cubic yards of reinforced shotcrete grade beams; and 1,900 cubic yards of reinforced shotcrete structural skin (carved and sculpted).

Repair Concepts. From Salter et al. (2007).

Construction of Ground Anchored Grade Beam Wall. From Salter et al. (2007).

Ground Anchor Installation. From Salter et al. (2007).

The stabilization works began in November 2004 and were completed in May 2006. According to the authors, it was innovative and challenging project, probably one of the largest in the United States. Its success resulted in "several million dollar savings in freeway widening construction costs for the taxpayers of California."

Reference:

David R. Salter, Walter Crampton, and Phillip Birkhahn. THE POINT PROJECT – LANDSLIDE STABILIZATION. 1st North American Landslide Conference June 3-8, 2007.

Landslide Mitigation. Experience from Japan.

Landslide Mitigation - Two Success Stories from Japan.

Landslide Mitigation: Piles, Anchors and Retaining Walls.

Why do people live on dangerous steep slopes in Guatemala?

2009-06-10T11:30:00.000-07:00

Simply, because they have no choice. Anne Maertens from The Western Front writes "facing extreme sprawl and few economic resources, thousands of Guatemalans choose to live in illegal squatter slums in Guatemala City."

The precarious settlements are built overnight on steep slopes, which are subject to life-threatening landslides. Photo by Scott Miles.

Huxley professor Scott Miles said that "the areas chosen are typically steep ravines that slope down from the edges of legitimate neighborhoods. The grade of the ravines is between 40 degrees and 70 degrees, which makes building difficult." During the rainy season, the weak structures get pummeled by rain, running off the roofs of neighboring houses, and often collapse. Huxley professor Rebekah Green notes that "in some cases, the shelters are completely washed out in a landslide that can leave people injured or dead." It is interesting that no roads lead into the illegal settlements. People come and go by climbing up and down the ravines, which are deep and intense.

What about the local government? Apparently, it can't help. In fact, government officials use the situation for their own benefits, trading the services like water and electricity for the votes of the citizens living in the slums. The good news is that some of the oldest settlements, which were established about 15 years ago, have now become legalized, and the houses are more permanent with sturdier, concrete foundations that can withstand the intense season of rains.

Low-income families build their houses on steep and unstable slopes, increasing their own vulnerability to landslide hazard.

Unfortunately, such a problem is very common in Central America, a place that has experienced a rapid demographic growth in the last few decades. Big cities attract many poor people from other parts of the country because of the hope for better lives. Due to the lack of money, they erect flimsy shacks literally wherever they can, often without regard for the potential risk.

What triggered the Landslide in Guatemala : Geological fault or Road Construction?

Landslide hazard in Bolivia: What makes La Paz a Landslide Hot Spot?

Landslide in Mexico City. Natural Disaster or Poor Urban Planning?!

The cause of catastrophic landslide at a Chinese mine is negligence. Again?!

2009-06-08T08:00:00.001-07:00

Poor safety standards and negligence seem to have triggered the catastrophic landslide at the Jiwei Mountain near the Chongqing municipality, China, on June 5, 2009. According to a China Daily report, some survivors said the landslide may have been triggered by excessive drilling and mining in the area. Some were quoted as saying they had seen rocks rolling down the hills prior to the landslide, but miners who escaped said owners had ordered them not to stop the drilling.

Rescue personnel walks past huge rocks as they search for survivors at the site where a landslide occurred Friday in Wulong county in southwest China's Chongqing Municipality, Saturday June 6, 2009. (AP Photo).

China's mines are the deadliest in the world, due to lax safety standards and the rush to meet demand from a booming economy. More than 3,000 died in coal mine accidents alone in 2008. Last September, a mudslide caused by the collapse of a mine waste reservoir in northern Shanxi province killed more than 250 people.

Landslide at a Chinese mine buries 106, more damage expected.

Are China's mines still the most dangerous in the world?

Mining and Landslides: What went wrong in China?

Landslide at a Chinese mine buries 106, more damage expected.

2009-06-07T19:07:00.000-07:00

A government spokesman in China said Saturday a landslide near Chongqing city may have left 106 people buried, including 26 miners. The debris covered an area 600m long (2,000ft) and 300m wide in a valley at Jiwei Mountain, Xinhua said. Some houses are buried 40m beneath the slide.

Rescuers search for survivors at a landslide site in the Jiwei Mountain area of Wulong county, Chongqing municipality, June 6, 2009. REUTERS/Stringer.

Officials said rescue efforts are occurring despite the presence of possible secondary disasters in the area as the landslide created unstable mountain slopes littered with large rocks. Rescue workers are also digging a canal to drain a lake that was created when the landslide blocked a river.

Are China's mines still the most dangerous in the world?

Mining and Landslides: What went wrong in China?

Three Gorges in China and Landslides.

Are China's mines still the most dangerous in the world?

2009-06-05T07:34:00.000-07:00

That seems to be true. China's mining industry has a poor safety record, with thousands of deaths reported every year. According to a BBC report, accidents in China's mines are common, due to poor safety standards, illegal mining and the rush to feed the demand from one of the world's fastest-growing economies. Unfortunately, another catastrophic landslide hit an iron ore mining area in southwest China's Chongqing Municipality on Friday, killing at least 80 people. The landslide happened at about 3 p.m. in the Jiwei Mountain area, in Tiekuang Township, about 170 kilometers southeast of the downtown area, Xinhua said. Millions of cubic meters of rock filled a valley and buried an iron ore plant and six houses. The trapped included quarry workers, residents and possibly passers-by. The landslide also led to a cut in power and communications in many parts of the town. In this photo released by China's Xinhua News Agency, firemen search for survivors at the site where a landslide occurred earlier in the Jiwei Mountain area, in Tiekuang Township, about 170 kilometers (about 105 miles) southeast of the downtown area, in southwest China's Chongqing Municipality, Friday June 5, 2009.

It is not clear what caused the accident, but an official with the Chongqing work safety supervision bureau told Associated Press news agency that the landslide did not appear to have been caused by the work at the mine.Similar landslides have been reported around China, including one last year where at least 277 people were killed when a shoddy holding reservoir burst and a three-story wave of mud and iron-mining waste inundated a valley in Shanxi province in northern China.

CHINA'S WORST MINE DISASTERS (From a BBC report).
Feb 1950: Yiluo mine, Henan province - 174 dead
May 1960: Laobaidong mine, Shanxi province - 684 dead
Sept 2000: Muchonggou mine, Guizhou province - 162 dead
Nov 2004: Chenjiashan mine, Shaanxi province - 166 dead
Feb 2005: Sunjiawan mine, Liaoning province - 210 dead
Nov 2005: Dongfeng mine, Heilongjiang - 171 dead
Aug 2007: Xintai City, Shandong province - 181 dead
Dec 2007: Rui Zhiyuan mine, Shanxi province - 105 dead
Sept 2008: Tashan mine, Shanxi province - 254 dead

Mining and Landslides: What went wrong in China?

Landslides in Sikkim, India: Types, Causes, Mitigation.

2009-06-01T22:37:00.000-07:00

Statistics show that hundreds of people are killed each year from landslides in Sikkim, India. For example, in 1968 alone, more than 33,000 people were killed by landslides. A recent example is dated back to May 11, when more than 800 tourists en-route to Gangtok from Chungthang in North Sikkim were trapped when a landslide of medium intensity blocked the North Sikkim highway.

A view of the Burdang landslide adjacent to National Highway 31A, Tista River. The landslide occurred in a phyllitic rock formation;the total volume of the released rock mass was between 100,000 and 200,000 m3. The average slope of the landslide is about 36 degrees. From Bhasin et al. (2002).

Two question typically arise when we look at landslide problems in different areas: "What are the main triggers/causes? and "How does the local community cope with the landslide problems?"Map of Sikkim. From Bhasin et al. (2002).

A study conducted by Rajinder Bhasin and colleagues (2002) gives some answers to the questions. It seems that the main trigger of landslides is rainfall. The authors note that "the intense rainfall in the region not only contributes to rapid erosion and weathering of the rock mass, but also increases the groundwater level that leads to reduction in the stability of natural slopes."Annual precipitation in Gangtok for the period 1987–1997. From Bhasin et al. (2002). The precipitation rate in the capital city of Gangtok is relatively high with an annual average of 3539mm. The monsoon period extends from April to September, while a dry season exists in mid winter.

Landslide Mitigation.

Chanmari landslide. On 8 June 1997, about 20,000 m3 of soil mixed with weathered rock fragments was released in the Chanmari landslide. This landslide occurred during a 5-h heavy rainfall (210 mm of precipitation). It killed eight people and destroyed several houses. A view of the Chanmari landslide showing the rock debris upstream from the developed area. From Bhasin et al. (2002).

High-capacity drainage canals made of flexible gabions along the Lokchu Khola at lower Chanmari. From Bhasin et al. (2002).

Mitigation works of the Chanmari landslide included drainage canals coupled with flexible gabion-like structures. It was designed to collect surface water and divert it to the main river. Planting tress, such as eucalyptus, that remove large amounts of water from the soil also contributed to stabilising the slopes.

Reference:

Why are there so many landslides in Darjeeling, India?

An old pipe causes a natural disaster in Sydney.

2009-05-29T18:36:00.000-07:00

The water pipe ruptured on Thursday and a subsequent road collapse swept two cars and a telegraph pole into a nearby park, leaving a 25m-wide hole in the exclusive eastern suburb of Bellevue Hill on Friday, May 29, according to The Australian.

Cars sit in the landslide left after a ruptured water main left a 25 metre wide crater in Bellevue and Victoria Roads at Bellevue Hill, May 29, 2009. Mitchell Blacklaw, ABC News.

A council worker inspects a 25m crater created after a landslide in Bellevue Hill, one of Sydney's most expensive suburbs May 29, 2009. REUTERS/Daniel Munoz (AUSTRALIA SOCIETY).

Sydney Water spokesman Brendan Elliott said crews inspected the area on Thursday afternoon and found storm water coming out of the ground. He also noted that the cast-iron pipe was rather old, laid in 1945. "Clearly, age does play a part but so too do the local soil conditions, traffic impacts, temperature changes, pressure changes. There's a whole range of things that could play a part in triggering the leak."

Repairs to the road at the intersection of Victoria and Bellevue roads could take several months to complete.

Brazil Dam Gives Way, killing 4 people. News in Pictures.

2009-05-28T18:59:00.000-07:00

Raging torrents from a ruptured dam swamped a small rural village of Cocal, population about 25,000, killing four people and destroying at least 120 homes in a region already devastated by more than a month of floods.

A view of a flooding area after a ruptured dam swamped a rural town in Brazil, Thursday, May 28, 2009. AP Photo.

Heavy rains in recent days swelled the reservoir behind the dam, increasing pressure that opened a 165-foot (50-meter) tear and eventually led to the rupture, the Piaui state government said in a statement. Officials launched an overnight rescue operation using five helicopters to transport victims to safety, and firefighters were sent to aid the victims. Piaui Civil Defense spokeswoman Vanize Lemos said at least 150 families were initially rescued.

Why are there so many landslides in Darjeeling, India?

2009-05-27T18:52:00.000-07:00

Darjeeling and Sikkim districts in India seem to be the areas that suffer the most from landslides every year. Just recently, nearly 100 landslides were triggered by Cyclone Aila in West Bengal's hill district of Darjeeling, killing 24 people. Why is Darjeeling so susceptible to landslides? and What areas are the most dangerous for people there?

The answer to the first question seems to be as follows: 1) the district is dominated by slopes ranging between 15° and 35°; and 2) the annual precipitation rate is relatively high, varying from a low of 3,000 mm to a high of 6,000 mm.

Landslide distribution map of Darjeeling, India. From Kanungo et al. (2008).

To find an answer to the second question, we should refer to a study by Kanungo and colleagues (2008) published in "Landslides". They conducted landslide risk assessment of Darjeeling, using concepts of danger pixels and fuzzy set theory, and determined the areas with high landslide risk. The results of their work are extremely useful to engineers and planners who are involved in various engineering projects such as route selection for a highway or general planning.

Landslide risk assessment map using concept of danger pixels. From Kanungo et al. (2008).

For example, landslide risk assessment map based on danger pixels approach shows that "habitation around Darjeeling and Ghum, a portion of road from Sonada to Ghum, the tea plantation in the southern part, and thick forests in the southeastern part of the study area were under risk due to landslides."

Reference:

D. P. Kanungo, M. K. Arora, R. P. Gupta,and S. Sarkar. "Landslide risk assessment using concepts of danger pixels and fuzzy set theory in Darjeeling Himalayas." Landslides (2008) 5:407–416.

Landslide Mitigation - Two Success Stories from Japan.

2009-05-26T18:38:00.000-07:00

"Landslides in Japan" contains many examples of successful practice related to landslide mitigation. I have already posted two excerpts (Landslide Mitigation. Experience from Japan. and Landslide Mitigation: Piles, Anchors and Retaining Walls.) from this book that described different methods and techniques typically used in Japan. There are two more examples (a bit old though) showing that in practice, more than one method is generally used for successful stabilization of slopes.

Kodomari Landslide.

Photo of the Kodomari landslide taken immediately after its occurrence. From "Landslides in Japan".

This rainfall-induced landslide took place in Hokkaido in 1978. It occurred on a steep slope (a dip of the slip plane was about 36 degrees). The landslide mass consisted of volcanic and sedimentary rocks.

The landslide site after the mitigation works were complete.
Mitigation measures included counterweight fill works at the toe of the slope, removal of soil from the top, construction of surface drainage and retaining walls.

Tamanoki Landslide.

Photo of the Tamanoki landslide taken immediately after its occurrence. From "Landslides in Japan".

This rainfall-induced landslide occurred in Niigata Prefecture in 1985, killing 10 people. The landslide mass consisted of weathered tuff breccia, tuff, and andesitic rocks.

The landslide site after the mitigation works were complete.

To stabilize this slope the following remediation works were carried out: soil removal, anchoring, piles, and construction of surface and underground drainage.

Landslides in Compostela Valley, Philippines: Rainfall and Illegal Logging again?

2009-05-21T07:25:00.000-07:00

“We are reiterating our campaign against illegal logging,” Compostela Valley Governor Arturo Uy said yesterday, vowing to wage war against timber poachers and the local officials in cahoots with them. This decision came just a few days after huge landslides hit a mining site in Sitio Boringot and a mountain area in Sitio Gumayan, both in Pantukan, Compostela Valley.
"The soil was saturated and softened by rainwater and the cloudburst that fell on top of the mountain unleashed torrents of water that swept away miners’ houses. There were no trees to hold the soil and water in check as miners had cut them down to use as tunnel braces and to build shelters," Uy said.

On Wednesday, civil defense authorities placed the death toll at 27. The victims were miners and members of their families, and fortune-hunters who disregarded government warnings to leave the slopes owing to the high probability of landslides and tunnel cave-ins during rainy season.

The landslide-hit mining town of Pantukan, Compostela Valley is seen in this aerial shot, May 19. — AFP.

Three Gorges in China and Landslides.

2009-05-19T21:55:00.000-07:00

Another landslide that took place at the Three Gorges, China on May 18 prompted me to write this post and look closer at the causes of slope instability in that area.

A new landslide occured on the northern bank of Wuxia Gorge in Chongqing Municipality on Monday, May 18, 2009. The landslide sent 20,000 cubic meters of mountain mass into the Yangtze River. Photo by Chongqing Times.

What is the Three Gorges?

The Three Gorges Dam in China is the largest hydropower project in the world. The dam site is located near Maoping town, Zigui County, Hubei Province. The main body of the dam, which is 181 m high and 2,310 m long, was finished by the end of 2006, and the reservoir level will reach a maximum of 175 m in 2009, allowing for full electric power capacity.
From Wang et al. (2008).

Geology of the area.
Fourniadis et al. (2007) used a published 1:200,000 geological map as reference to visually interpret and identify the major lithological types and their geological structure settings in the study area. Lithological formations were grouped according to landslide susceptibility and classified into three stability-related broad categories: (a) limestone (massive limestone and dolomite); (b) sandstone (inter bedded sandstone/shale/marl);and (c) mudstone (mudstone, Quaternary sand and gravel).

From Fourniadis et al. (2007).

Fourniadis et al. (2007) showed that "while steep mountain slopes in limestone are more susceptible to rockfalls, valley slopes formed in sandstone and shale sequences appear to be more susceptible to block slides. Also, shallow debris slides are likely caused by the presence of soft lithologies, such as mudstone and Quaternary deposits, and by the high level of dissection density as a result of road construction and urban development."

Examples. Qianjiangping landslide.

A view of the Qianjiangping landslide (This photo is taken by Zhang, July 15, 2003). Wang et al. (2004) suggested that "the high water level in Qinggan-he River caused by the impoundment of the reservoir was the trigger of the landslide."

Shuping landslide.

Photo of the Shuping landslide. From Wang et al. (2008).

The Shuping landslide was reactivated due to the impoundment of the Three Gorges Dam Reservoir in 2003. Based on the monitoring data, it was found that "movement of the Shuping landslide corresponded to water level change in the Three Gorges Reservoir. Movement of the landslide occurred during the wet season when the reservoir level is lowered for flooding control."

References:

Fa-Wu Wang, Ye-Ming Zhang, Zhi-Tao Huo, Tatsunori Matsumoto, Bo-Lin Huang. "The July 14, 2003 Qianjiangping landslide,Three Gorges Reservoir, China." Landslides (2004) 1:157–162.

I. G. Fourniadis, J. G. Liu, P. J. Mason. "Regional assessment of landslide impact in the Three Gorges area, China, using ASTER data: Wushan-Zigui." Landslides (2007) 4:267–278.

Fawu Wang, Yeming Zhang, Zhitao Huo, Xuanming Peng, Kiminori Araiba, Gonghui Wang. "Movement of the Shuping landslide in the first four years after the initial impoundment of the Three Gorges Dam Reservoir, China." Landslides (2008) 5:321–329.

Landslide in China destroys a residential building. News in Pictures.

2009-05-17T18:28:00.000-07:00

Picture taken May 16, 2009. REUTERS/China Daily.

The landslide happened on Saturday in the Jiuzhou development district of Lanzhou. About 20,000 cubic meters of soil collapsed on a part of the building, killing seven and affecting more than 30 families.

About 500 armed police and firefighters are involved in search for survivors. The situation remains critical as several other cracks of about 20 to 30 cm long were spotted on the hill, and rescuers said another landslide is possible.

Rockfall triggered by the 2008 Wenchuan Earthquake, China. Photo of the week.

2009-05-13T07:23:00.000-07:00

The Wenchuan Earthquake shook Sichuan Province of China on May 12, 2008. The epicenter was 80 kilometres west-northwest of Chengdu, the capital of Sichuan, with a depth of 19 kilometres The earthquake triggered more than 900 rockfalls, as well as landslides and debris flows at 15,000 sites.

One year since the Wenchuan earthquake in China. Still a lot of work to do.

2009-05-11T19:13:00.000-07:00

Today is one year since the Wenchuan earthquake, a quake (Ms=8.0) that took lives of more than 20 000 people in Sichuan Province, China. It also triggered a great number of slope failures, especially rockfalls, and created more than 30 high-risk landslide dams. Yueping Yin and colleagues conducted landslide hazard assessment of the areas hit by the earthquake and presented their results in one of the latest issues of "Landslides". According to the study, before the Wenchuan earthquake, "there were a total of about 5,430 potential geohazard sites in the 42 affected counties (cities) of Sichuan Province." The earthquake triggered landslides, rockfalls, and debris flows at 15,000 sites. In addition, 4,970 new potential geohazard sites were revealed, probably as a result of the earthquake.

Comparative histograms of geohazards in the counties affected by the Wenchuan earthquake before and after the earthquake. From Yueping Yin et al. (2009).

Yueping Yin et al. (2009) noted that "after the earthquake, the number of potential geohazard sites increased by 237%." This means that the government still has a lot of work to do such as stabilizing slopes and preventing debris flows. Unfortunately, due to the great scale of the disaster such works might take much more time than one can expect.

Reference:

Yueping Yin, Fawu Wang, Ping Sun (2009). Landslide hazards triggered by the 2008 Wenchuan earthquake, Sichuan, China. Landslides, online first.

Wildfire in California, Mudslides Next?

2009-05-10T20:05:00.000-07:00

AFP reports that a wildfire in Santa Barbara, California, caused by sparks from power tool equipment has damaged 80 homes, scorched 8,700 acres (3,500 hectares) and forced roughly 30,500 residents to evacuate. However, these numbers do not draw the real picture of destruction. The history of wildfires in California says that more damage should be expected during rainy seasons as debris flows are likely to generate on the burned slopes. The photos below show that the fire destroyed vegetation on hillsides in the San Marcos Pass area, making the slopes more susceptible to rains.

A strike team from the Hopland Fire District in Mendocino County, Calif., stand watch over a burned hillside in the San Marcos Pass area, Santa Barbara, Calif., Saturday, May 9, 2009.(AP Photo/Reed Saxon).

Read here how to prevent mudslides on burned slopes.

Landslides in Daniel’s Harbour are caused by sensitive clay?!

2009-05-08T08:14:00.000-07:00

A small community in northern Newfoundland has been hit with another landslide, but the town's mayor says no homes have been lost, the Canadian Press reports. The latest slide means the community's motel is now only 40 metres from a cliff that overlooks the Gulf of St. Lawrence. At the present time, it is not clear whether the residents will be relocated due to the imminent danger of new landslides.

Daniel's Harbour was rocked by a series of landslides in late 2006 and the spring of 2007.

A landslide in October 2006 saw tonnes of clay tumble away from the cliffs of Daniel's Harbour. CBC.

A landslide in April of 2007 led to the destruction of two buildings, after one home was sucked down in the landslide event and the other structures were deemed unsafe and burned. Star File Photo.

A geotechnical study conducted to investigate the cause of landslide events in Daniel’s Harbour revealed that "the ground in the area rested on a layer of weak (sensitive) soil." This might lead to "a fast, brittle failure causing a large scale slide,” the study stated. “If site conditions support this scenario, a potential failure could extend to the pond across the road resulting in a loss and destruction of municipal infrastructure and residential dwellings.” However, no timelines were suggested in relation to this reported risk assessment, but further study was recommended.

News in Pictures. 30 killed and 200 000 homeless due to floods and mudslides in Brazil.

2009-05-06T23:01:00.000-07:00

An aerial view of flooded streets in the Boca do Rio neighborhood of Salvador, Brazil, Tuesday, May 5, 2009. Floods and mudslides from months of heavy rains in northern Brazil have driven more than 200,000 from their homes, killed at least 30 people and cut off shipments from a huge Amazon iron mine, according to officials. (AP Photo/Manui Dias, AGECOM). Read more.

News in Pictures. Floods and Mudslides Kill Three In Tajikistan.

2009-05-06T17:51:00.000-07:00

Rainstorms, floods, and mudslides in recent days have killed at least three people in Tajikistan's southern Khatlon province, RFE/RL's Tajik Service reports. Dozens of houses were completely or partly destroyed in the Khuroson, Yvon, and Muminobod districts of Khatlon province.

Sliding surface in Granite. Photo of the Week.

2009-05-05T17:58:00.000-07:00

I have decided to post interesting photos relating to landslides from my archive. I will call it “Photo of the week.” Today, there are two photos of the shear band/ sliding zone in granite. It is not easy to find such a zone in granite, however, I was lucky; it was exposed due to road construction.

How dangerous are reactivated landslides in Italy?

2009-04-30T18:36:00.000-07:00

Reactivated landslides are very common in Emilia-Romagna Apennines, Northern Apennines, Italy. The majority of them are concentrated in areas where the slope gradient ranges from 8 to 11°, which is the usual slope angle of “Argille Scagliose”. “Argille Scagliose” is a type of rocks that consists of blocks of different dimensions and lithologies (mainly arenites and limestones) included within a clay matrix. The thickness of reactivated landslides is usually no more than a few tens of metres. The majority of them (52%) reaches a depth ranging from 10 to 30 m.

The 2.6 km long Morsiano landslide is a typical examples of reactivated landslides in Emilia-Romagna Apennines. It has a large crown, relatively narrower middle “channel” –corresponding to the area of flow– and a wide basal fan reaching the valley floor, with a modest or null slope inclination. Photo by G. Bertolini. From Bertolini and Pizziolo (2008).

Reactivation Mechanism

The reactivation mechanism observed for many landslides is shown in the figure above. Bertolini and Pizziolo (2008) note that "when a reactivation occurs, the first movements are rotational slides in the source area that cause a regression of the main scarp. The displaced material reaches a liquid state of consistency, thus producing earth/mud-flows moving downward as far as the landslide body's mid-section. This process leads to partial or full reactivation of the ancient slide.

Are these reactivated landslides dangerous?

The study shows that only few earth flows are perpetually active while the majority of them alternate periods of activity with periods of dormancy lasting from a year to a century. The question is "are these reactivated landslides dangerous then?" Bertolini and Pizziolo (2008) say "yes". It is hard to believe at first but permanently active landslides are usually less problematic with regard to risk-management than dormant ones. The reason is quite simple - "the longer the dormancy period, the more people have erected buildings and structures upon the landslide body. If the landslide reactivation occurred more frequently, the more people were aware of the danger and avoided building." The following example illustrates the point.Bertolini and Pizziolo (2008) say that this large Corniglio landslide was "deceptively safe until complete reactivation in 1994 after nearly a century of dormancy. In the seventies the medieval village –which stood in a relatively safe position, out of the main landslide body–expanded toward the dangerous part of landslide: in 1902 only ten edifices were exposed to risk, in 1994 this number had increased to 70."

Reference

Giovanni Bertolini and Marco Pizziolo (2008). Risk assessment strategies for the reactivation of earth flows in the Northern Apennines (Italy). Engineering Geology 102 (2008) 178–192.

Landslide Mitigation: Piles, Anchors and Retaining Walls.

2009-04-27T19:02:00.000-07:00

In the previous post, I took a look at some examples of landslide mitigation techniques in Japan that fall into the category of "landslide control works", according to "Landslides in Japan (1996)". They are primarily designed to modify "natural conditions of landslides such as topography, geology, and ground water conditions." Today I will draw your attention to the "landslide restraint works", which are mainly used to stabilize unstable slopes.

Piles are used to "tie" the landslide mass with the bed rocks below in order to "restrain" the movement. Steel piles filled with concrete are typically used for this purpose.

In special cases, large diameter (from 1.5 to 6.0 m) cast-in-place piles are employed as they are more resistant to bending stresses.Anchors are often used in slope stabilization projects in Japan. This method utilizes the tensile force of anchor bodies which are placed throughout the sliding mass and fixed in the bed rocks. The advantage of anchors is that great restraint forces can be obtained from a relatively small tendon.

Retaining walls are designed to prevent small-sized or secondary slides that often occur at the toe of large landslides. In Japan, crib walls seem to be more common than conventional reinforced concrete retaining walls. The main reasons for this are 1) large-scale earth movement and 2) numerous springs which are commonly found at the toe.

Landslide Mitigation. Experience from Japan.

2009-04-22T23:55:00.000-07:00

Japan is probably the only country in the world where the government invests quite a bit into landslide mitigation work. As a result, advanced techniques have been developed and improved there over the past few decades. According to "Landslides in Japan (1996)", there are two major approaches to landslide mitigation: "control works", and "restraint works". Lets look at some examples of landslide control works.

"Surface drainage ditches" - designed to collect and and remove rain water.
"Intercept trench" - designed to collect and and remove ground water from the shallow part of a landslide.
Horizontal drain pipes are designed to remove ground water from the depth range of 3-5 m. They are 30-50 m long and installed at the angle range of 10-15 degrees.

Drainage wells of 25 m deep and at least 3.5 m in diameter are constructed in the areas with high ground water concentration.

Tunnels are typically used to connect drainage wells.

Soil removal is probably the most effective method but it can be used only for small to medium-sized landslides.

Buttress fill work. The buttress fill is typically placed at the toe of the landslide in order to counterweight the landslide mass. It is often used with the soil removal method.

International School on ''Landslide Risk Assessment and Mitigation'' in Italy

2009-04-17T18:56:00.000-07:00

LARAM is an International School on “Landslide Risk Assessment and Mitigation” that was founded by the University of Salerno. Every year international experts in the field of landslide risk teach about 40 PhD students from around the world the fundamentals of landslide risk assessment. This year it will be held in Salerno, from 6th to 19th of September. More information can be found here
http://www.laram.unisa.it http://www.laram.unisa.it/2009-index.htm http://www.laram.unisa.it/community-lecturers.htm

Eligible students must be studying for a PhD in: Civil Engineering, Environmental Engineering, Engineering Geology or a related course.http://www.laram.unisa.it/2009-selectioncriteria.htm
Tuition, accommodation and board are free of charge.
The deadline for applications is 25 May 2009.
Apply online at: http://www.laram.unisa.it/2009-application.htm

A massive landslide kills 16 people in Kyrgyzstan.

2009-04-16T00:42:00.000-07:00

A massive landslide swept through the village of Raikomol in the southern Jalal-Abad, Kyrgyzstan on Thursday, killing at least 16 people. Emergency Situations Minister Kamchybek Tashiyev says that torrential rainfall in recent days has left villages in the mountainous region heavily prone to mudslides.

Photo by NTV.

Rescue workers rushed to the scene to recover the bodies and help survivors, a ministry spokesman said.

Preliminary reports said the landslide destroyed three houses. All the residents of the ruined houses are believed to have died.

Seismically induced failures in Italy.

2009-04-10T20:41:00.000-07:00

Italy is characterized by seismic activity due to the tectonic processes that are active in the Mediterranean area. In the last two centuries more 20 destructive earthquakes were recorded, whose magnitude was equal to or greater than 6. The two last destructive earthquakes hit the southern and central Apennine areas in 1980 (Irpinia Ms 6.8 earthquake) and in 1997 (Umbria–Marche Mw 6.0 earthquake).

Location of earthquakes with data on seismically induced ground failures. From Prestininz and Romeo (2000).

Prestininz and Romeo (2000) studied a great number of earthquakes that occurred in Italy in the last millennium (with a nominal epicentral intensity equal to or greater than VIII in the Mercalli–Cancani–Sieberg (MCS) intensity scale) and related phenomena such as landslides, ground cracking, surface faulting, liquefaction, and topographic changes of the ground level.

Frequency distribution of earthquake-induced ground failures. From Prestininz and Romeo (2000).

About 1800 ground effects have been identified, among which Landslides(41%), Fractures (32%), Liquefaction (18%), Topographic changes (8%), and Surface faulting (1%). Landslides are classified on the basis of the prevailing material in which they occurred. Fractures related to slides indicate ground cracks from which landslides subsequently developed, for instance, owing to intense rainfall.

Stravignano Bagni (Nocera Umbra). Travertine rock fall, whose volume amounted to several hundred cubic metres. From Esposito et al. (2000).

Afrile (Foligno). Open fractures forming an arch several hundred metres long (main scarp of a rotational slide) following the 1997 Umbria–Marche earthquake. From Esposito et al. (2000).

References:

Alberto Prestininz, and Roberto Romeo (2000). Earthquake-induced ground failures in Italy. Engineering Geology 58, 387–397.

Eliana Esposito, Sabina Porfido, Armando L. Simonelli, Giuseppe Mastrolorenzo, Gianmaria Iaccarino (2000). Landslides and other surface effects induced by the 1997Umbria–Marche seismic sequence. Engineering Geology 58, 353–376.

Strong quake in Italy kills 150. A scientist says the tragedy could have been avoided.

2009-04-06T18:52:00.000-07:00

The quake, centered near L'Aquila about 70 miles northeast of Rome, struck at 3:32 a.m. Monday, followed by a series of aftershocks that continued into Tuesday morning. The original quake, which measured 6.3 on the Richter scale.

The quake hit 26 towns and cities around L'Aquila. The town of Onno, population 250, was almost leveled.

Aerial view of collapsed buildings around L'aquila April 6, 2009. A powerful earthquake struck central Italy early on Monday, killing more than 100 people, making up to 50,000 homeless and flattening entire medieval towns while residents slept. REUTERS/Livio Anticoli/Pool (ITALY DISASTER IMAGE OF THE DAY TOP PICTURE).

L'Aquila, whose name means "The Eagle" in Italian, was built around 1240 by Holy Roman Emperor Frederick II and was under French, Spanish and papal domination during the centuries. Some 10,000 to 15,000 buildings were either damaged or destroyed, officials said. L'Aquila Mayor Massimo Cialente said about 100,000 people were homeless. Many modern structures have failed to hold up to the rigors of quakes along Italy's mountainous spine or in coastal cities like Naples. Despite warnings by geologists and architects, some of these buildings have not been retrofitted for seismic safety.

Photo released by the Italian Guardia Forestale (Forestry Police Force) showing an aerial view of the destruction in the city of L'Aquila, central Italy, Monday, April 6, 2009. (AP Photo/Guardia Forestale, HO).

Giampaolo Giuliani, a researcher for a physics lab in the nearby Gran Sasso, claimed in media interviews that he forecast the quake days earlier by measuring the amount of radon gas released by the earth, but was muzzled by officials. The researcher had said that a "disastrous" earthquake would strike on March 29, but when it didn't, Guido Bertolaso, head of Italy's Civil Protection Agency, officially denounced Giuliani in court last week for "false alarm." Using a method that measures gasses emitted by small tremors, Giuliani, it turns out, was partially right. A much smaller seismic shift struck on the day he said it would, with the truly disastrous one arriving just one week later.

Can animals cause mudslide? Apparently Yes!

2009-04-04T16:49:00.000-07:00

I don't know how to name the cause of this mudslide, maybe "animal activities". The Seattle Times reported that "a breached dam built by a family of beavers sent a 10-foot cascade of water, trees and debris crashing through a little beachfront community near Clinton on Whidbey Island, Washington, USA.
The trouble started on Friday when the beaver dam burst, plugging a culvert near Glendale Road and filling the creek. The road gave way, sending what officials called a “wall of water” blasting into homes. At least eight houses were ruined, but no one was hurt.

A thick layer of mud, water and debris remains on the waterfront roadway after Friday morning's damaging slide. (Photo by Island County Fire District #3 Deputy Chief Jon Beck). From KOMONews.com.

The "wall of water" was carrying mud, logs, concrete and debris when it blasted into the homes.

Robert Naiman, a professor at the University of Washington's School of Aquatic and Fishery Sciences said beavers, native to the Northwest, build dams to find safety from predators such as wolves and mountain lions and to create a good habitat for themselves. They build homes in the middle of a pond, and they store the tasty wood sticks just outside. When beaver dams breach, it's usually because of structural failure at the bottom.

Landslides and "Sliding-Surface Liquefaction"

2009-04-03T07:26:00.000-07:00

Liquefaction failures of slopes typically result in extensive property damage and significant loss of life. Japan seems to have suffered the most from this type of disaster in the past few decades. For this reason, it is not surprising that the concept of sliding-surface liquefaction was proposed and developed in Japan by K. Sassa and colleagues. It describes the process of liquefaction that occurs "within the shear zone, where a considerable amount of grain crushing should occur during the shearing process, thus generating excess pore pressures and lowering the pore-pressure dissipation rate." The concept was successfully used to explain the mechanism of the Nikawa landslide, a failure that killed 34 people in Kobe, following the 1995 Hyogo-Ken Nanbu (Great Hanshin Earthquake) earthquake.

The Nikawa landslide was the largest slope failure triggered by the 1995 Hyogo-Ken Nanbu (Great Hanshin Earthquake ) earthquake. From Sassa et al. (1996).

The landslide mass was mainly composed of colluvial sand with some layers of silt, underlain by granite. It is interesting that the ground water level was low as the landslide occurred during a dry season. However, the results of laboratory tests suggested that excess pore-pressures generated in the soil as a result of grain crushing that took place along the sliding surface. This process led to a significant drop in the strength of soil. The observed phenomena are clearly different from the "conventional" liquefaction which is generally associated with the collapse of the meta-stable soil structure of a loose, cohesionless soil mass.

Reference:

Sassa K, Fukuoka H, Scarascia-Mugnozza G, Evans S (1996) Earthquake-induced landslides: distribution, motion and mechanisms. Soils & Foundations, Special Issue for the Great Hanshin Earthquake Disaster, pp 53–64.

Landslides triggered by the 2008 Iwate-Miyagi Nairiku Earthquake.

2009-04-01T06:55:00.000-07:00

The Iwate-Miyagi Nairiku Earthquake of June 14, 2008 struck the mid Tohoku region, northeastern Honshu, Japan. The JMA magnitude was estimated at Mj 7.2, and the moment magnitude measured by the USGS was Mw6.9.

Map of aftershocks and active faults. By Yukinobu Okamura.

Over 200 felt aftershocks were observed in the first 24 hours, with about 400 total in the first seven days. The Japan Times reported that "hundreds of aftershocks triggered landslides that dramatically altered the hilly landscape, leaving around 290 residents and tourists stranded in various areas while cutting off power to nearly 30,000 households."

Aerial photo of the largest landslide with Kurikoma Volcano rising behind.

Aratozawa landslide before and after the earthquake. The landslide was composed of weakly cemented weathered volcanic ash, and volcanoclastic material.

Large rotational slides caused the impounding of nearly a dozen small quake lakes behind debris that blocked valleys and formed natural dams. According to GEER Web Report 2008 v.1, "quake dams formed on the Sanhasama river and the Nihasama river, five formed on the Hasama river in Kurihara, Miyagi Prefecture, and four on the Iwai river near Ichinoseki, Iwate Prefecture."
Landslide dam and quake lake at Ichinonobara. The length of the dam was estimated to be about 700 m, the width - 200m. Total volume of the landslide mass was about 1,730 x1000 cubic m3.

The most tragic debris flow caused by the earthquake buried a Japanese style hotel and killed 7 people at Komanoya Spa. The volume of the collapsed soil was estimated to be 1.5 million m3. The scarp was about 200 m long, 300 m wide, and 30 m deep.

Unno and colleagues from Nihon University, Japan, noted that the debris flow traveled about 10 km from the scarp to the Gyoja-taki site. The difference in elevations between these two points was about 1 km. The debris flow contained big boulders and trees, the dominant material was fully saturated fine-grained soil with the plasticity index about 31.

Reference:
Robert Kayen, Brady Cox, Jorgen Johansson, Clint Steele, Paul Somerville,Kazuo Konagai, Yu Zhao, Hajime Tanaka (2008). "Geoengineering and Seismological Aspects of the Iwate Miyagi-Nairiku, Japan Earthquake of June 14, 2008," GEER Web Report 2008 v.1.

An ancient landslide caused the second worst disaster in California history?!

2009-03-22T06:56:00.000-07:00

After the great San Francisco earthquake and fires that claimed 2000 lives in 1906, the St. Francis Dam failure in 1928 is said to be the second worst disaster in California history. The dam gave way on the eve of March 12th, just minutes before midnight, creating a treacherous wall of water that swept away more than 500 lives in the darkness. An article recently published by Signal recounts the historic collapse of the St. Francis Dam, suggesting that the failure was caused by an ancient landslide.

The St. Francis Dam was built from 1924 to 1926. The immense concrete structure towered 185 feet over the canyon, holding back an artificial lake almost three miles long. The water weighed nearly 52 million tons. by George R. Watson.

The dam was built by William Mulholland, "an illiterate and self-educated man who eventually became the most renowned civil engineer in California, building 19 dams through his career the most."

William Mulholland, left, and H.A. Van Norman inspect the remains of the St. Francis Dam after its collapse. by George R. Watson.

At a time when the San Fernando Valley's population tripled and land prices escalated 500 percent, Mulholland saw the need for a dam to provide water for the burgeoning area of Los Angeles. Unfortunately, the place he selected was "actually the site of an ancient landslide, and the ground was still moving - information that geologists in the 1920s would not have had access," according to David Rodgers, a professor at the Missouri University of Science and Technology.

The St. Francis Dam after the catastrophic failure. By George R. Watson.

It is interesting that a few days before the collapse the dam keeper expressed concern over leaks, but Mulholland, who inspected the dam just 12 hours before the disaster, declared the dam safe.

What caused the Tsaoling landslide triggered by the 1999 Chi-Chi earthquake, Taiwan?

2009-03-18T06:44:00.000-07:00

An earthquake (Ms=7.7), which became known as the "921-earthquake"’, occurred in central Taiwan on September 21, 1999. This earthquake has also been referred to as the "Chi-Chi earthquake" because its epicenter was located near Chi-Chi, a small town in central Taiwan. About 26,000 earthquake-induced slope failures have been identified over an area of 375,000 ha. In addition, two huge rockslide avalanches were triggered by this earthquake: the Chiu-fen-erh-shan landslide and the Tsaoling landslide. Since then, several researchers have studied the Tsaoling landslide mostly because of the high possibility that such an event might occur again.

A view the Tsaoling landslide (Source area). Photo by Dr. H. Suwa. From Chigira et al. 2003.

Chigira and colleagues studied the mechanism of this landslide in detail. Their research shows that the Tsaoling landslide has slid five times since 1862; landslides have developed retrogressively upslope from the first occurrence on 6 June 1862. The trigger of the 1862 landslide is not known. Earthquakes triggered the 1941 and 1999 landslides, and rain induced the 1942 and 1979 landslides.

Geologic cross-section of the Tsaoling landslide area. From Chigira et al. 2003.

It is interesting that the dip of the failure plane formed in fine sandstone and shale of Pliocene was considered too gentle, about 14 degrees, to generate such a huge landslide, even if there were an earthquake tremor, because the peak strength of shale and sandstone was too large. So what caused the Tsaoling landslide?

It seems that the answer is "weathering". Weathering of shale by the iteration of drying and wetting and probably sulfuric acid was one of the major causes of the intermittent retrogressive development of landslides, according to Chigira et al. (2003).

Slaking of the shale (Ms) intercalated with sandstone (Ss). The shale is fragmented but sandstone is not. From Chigira et al. 2003.

Chigira et al. (2003) also suggested that "the weathering was likely accelerated by the removal of overlying beds during the landslides of 1941 and 1942."

Reference:

Masahiro Chigiraa, Wen-Neng Wangb, Takahiko Furuyac, and Toshitaka Kamai. (2003). "Geological causes and geomorphological precursors of the Tsaolinglandslide triggered by the 1999 Chi-Chi earthquake, Taiwan," Engineering Geology 68 (2003) 259–273.

Landslide Hazard on Roads in Norway.

2009-03-13T17:35:00.000-07:00

Landslides and related phenomena are very common on roads in Norway. The statistics paint a bleak picture: more than hundred slides are registered every year only in the Northern Region of Norway (Aronsen 2005). Natural hazards on roads between 2000 and 2004 in the Northern Region. From Aronsen 2005.

A mudslide that occurred in Namsos (about 530 kilometers north of Oslo) on Friday is another example showing how serious the problem is. State radio network NRK reported that six houses and up to three cabins were caught in a slide that was about 200-300 yards (meters) wide. The disaster took place near a road construction site, and it is believed that the mudslide was caused by blasting or excavation.

Damaged buildings lie at the edge of a fjord, following a mudslide near Namsos, Norway, Friday March 13, 2009. Several houses and cabins were destroyed in the mudslide, which happened near a road construction site.(AP Photo/Scanpix, Norway).

In Norway, roads are naturally concentrated along the shoreline. According to Helgaas (2005), "the roads are exposed to a variety of problems with unstable terrain, and snow avalanches are a major threat to road traffic in the winter season." There seem to be several factors that lead to embankment failures.

Geology, Quick clay. During construction of a new highway in 1988 a large slide in quick clay and loose sand occurred in Balsfjordin Troms County. As a consequence of this landslide the highway had to be relocated to an area above the marine limit.

The Balsfjord Landslide, August 1988 (Photo byRygg & Oset). From Helgaas (2005).

Insufficient drainage systems create instability problems for road embankments made of silty soil, especially in the spring. Snow melting causes high water pressures in the road fills which are typically made of material with poor drainage characteristics.

Many of the cut slopes in silty clay cause problems when the frozen ground melts in spring. The inclination of cut slopes earlier used to be 1:1.5. In order to solve the problem the cut slopes are now normally built with an inclination of 1:2 to 1:3.The highway no. E8 30 km south of the city of Tromsø: Slope failure in the cuttings. From Helgaas (2005).

References:

Helgaas, O. (2005). "Protection against landslides and avalanches on public roads in Northern Norway," Landslides and Avalanches: ICFL 2005 Norway.

Aronsen, V. (2005). "Application of a priority-model for protection works against slides on public roads in Northern Norway," Landslides and Avalanches: ICFL 2005 Norway.