March 26, 2014

The search continued today for victims of the enormous landslide that destroyed much of Oso, Washington, last weekend. The death toll currently stands at 24, but as many as 175 people remain unaccounted for. State officials disclosed yesterday that rescuers have located 8 more bodies but have not been able to extract them from the massive pile of mud and debris. “We haven’t lost hope that there’s a possibility that we could find somebody alive,” local fire chief Travis Hots told reporters last night. However, no one has been pulled out alive from the muck for four days.

On March 22, a giant wall of rain-saturated earth slid off the mountain, burying much of Oso, a hamlet 60 miles (96 kilometers) north of Seattle. The landslide brought down an unimaginable amount of earth–as much as three times the volume as there is concrete in Hoover Dam, according to one engineer’s estimate. After surveying the area from the air, Washington Governor Jay Inslee said the landslide “basically cut a mountain in two” and deposited it on the town below, causing “devastation beyond imagination.” Washington state geologist Dave Norman reported to the media that the landslide left behind a cliff known as a head scarp that is 600 feet (183 meters) high. “This is one of the biggest landslides I’ve seen,” he noted. The mudslide destroyed 49 houses, temporarily dammed a river, and left a square mile wasteland in its wake.

Slides and floods have long threatened Oso and other nearby communities. In 1999, the Army Corps of Engineers specifically warned of “the potential for a large catastrophic failure” in the valley because erosion caused in part by a nearby river could “reduce stability of the entire slide mass.” However, state emergency management officials–declaring that they had done everything possible to reenforce the hillside with retaining walls–attributed Saturday’s landslide to near-record rains on loose glacial soil. The area received 7.14 inches of rain in the first 19 days of March.

Hurricane Jova made landfall today on Mexico’s west coast in the state of Jalisco with maximum sustained winds of 100 miles (160 kilometers) per hour. Government officials warned of coastal flooding and landslides along a 210-mile (340-kilometer) stretch between the resort towns of Manzanillo and Cabo Corrientes. In Manzanillo, the storm prevented ships from sailing into and out of Mexico’s main port of arrival for cargo containers. Some 13 container ships rode out the storm in the city’s harbor.

Manzanillo © Corbis/Alamy

Down the coast, a storm-triggered mudslide swept away a hillside house, killing two people. Two children were injured when the force of the wind and rain caused the walls of their brick house to collapse.

After passing within about 12 miles (20 kilometers) of the resort city of Puerto Vallarta, Jova moved inland and steadily weakened to tropical storm status, according to the U.S. National Hurricane Center.

Additional World Book article:

• National Weather Service

Heavy rain and thick cloud cover and numerous landslides hamper rescue efforts in the Himalayan regions of India, Nepal, and Tibet hard hit by a magnitude-6.9 earthquake on September 18. The epicenter was in the northern Indian state of Sikkim, where thousands of buildings collapsed and more than 65 people are known to be dead. At least 17 people die in landslides at a hydroelectric plant under construction. The damage is also widespread in Nepal and Tibet, where at least 25 people are reported killed. “The earthquake has loosened the hill faces, and when it rains, it causes landslides. So the situation is still very dangerous,” reports Deepak Pandey, a spokesman for the Indo-Tibetan border police.

The quake occurred at the boundary between two of the tectonic plates that make up Earth’s outer surface. There, the Indian-Australian Plate is pushing beneath the Eurasian Plate. About 45 million years ago, a plate that includes what is now the country of India collided with the southern edge of the Eurasian Plate, which includes Europe and most of Asia. The Indian-Australian Plate caused rock in the Eurasian Plate to crumple and fold. Over millions of years, the Himalaya, the world’s highest mountain system, was formed.

Additional World Book articles:

• Plate tectonics
• Seismology
• When the Earth Moves (special report)