Quantcast

NASA Satellite Images Show Massive Ice Avalanche in Tibet

Climate

On July 17, 130 million cubic yards of ice and rock suddenly let go from a glacier in Tibet, hurtling down six-tenths of a mile and killing nine herders along with 350 sheep and 110 yaks. Scientists were baffled. Now, by examining satellite images before and after the event, they think it is an example of a rare glacial surge, when a glacier moves at 10 to 100 times its normal speed. Some researchers believe that climate change at high elevations can trigger such surges.

NASA

"It doesn't make sense," said Tian Lide, a glaciologist at the Chinese Academy of Sciences' Institute of Tibetan Plateau Research (ITPR) in Beijing, who runs a research station in Rutog. Most avalanches occur on slopes of 25 to 45 degrees, but the Rutog avalanche, as this event is known, started from a flat area some 17,000 to 20,000 feet above sea level. When it came to rest, it covered an area of nearly 3.8 square miles to a depth of almost 100 feet. The only other event of comparable size was the 2002 collapse of the Kolka Glacier in the Caucasus. That avalanche killed 140 people.

An entire tongue of the Rutog glacier in Northwest Tibet collapsed at once. Lide noted that the glacier came down with such force that it widened the gully it came to rest in. Two different satellites captured before-and-after pictures of the area. NASA's Operational Land Imager acquired an image on June 24, just about a month before the avalanche. The European Space Agency's Sentinel-2 satellite captured an image of the debris field on July 21, days after. The pre-collapse imagery revealed that the glacier was already showing signs of change.

Glacial surges can be caused by meltwater at the base of the glacier, which essentially lubricates the surface it flows over. These types of surges can have a sudden onset and a very high flow rate. Many surge-type glaciers are found in Western Tibet.

Researchers from Moscow State University and the University Center for Engineering Geodynamics and Monitoring in Moscow have investigated the Kolka avalanche on the ground. Glacial surges are not new there; events dating back to at least 1902 are known. They found striations in the moraine rocks, which they'd never seen before.

"Moraine rocks are not scraped by the glacier because they move with it," Dmitry Petrakov, a geologist at Moscow State University, said. "But at Kolka, the collapse happened so fast that the ice mass must have simply flown over the moraine, producing striations several millimeters deep in minutes."

They found that the avalanche moved with tremendous speed, perhaps up to 112 miles per hour. They concluded that it was a surge event.

A year after the Kolka collapse, the researchers still found the area unstable. In the days following the Rutog avalanche, cracks occurred in nearby glaciers. Temperatures in the Tibetan plateau have risen 0.4 degrees Celsius per decade, twice the global average. One-tenth of the permafrost has melted in just the past decade. Rapidly melting glaciers have added to the number of lakes by 14 percent since 1970 and 80 percent of existing lakes have grown, flooding towns and pastures. In addition, precipitation in the area has increased 12 percent since 1960.

EcoWatch reported Aug. 26 on the issues facing this area, known as the "Third Pole." The Himalayas and Tibetan Plateau hold the largest mass of ice on Earth after the polar regions. The loss of these glaciers threatens the water supply for 1 billion people in China, India and Tibet, Nepal, Bhutan and Southeast Asia.

In response to the Rutog avalanche, China Radio International reported, "Experts believed that the icefall is a result of global warming, which has caused melting and cracking of the glaciers."

Those killed in the Rutog avalanche were residents of Dungru village in Rutog county in Southwest China's Tibet autonomous region.

EcoWatch Daily Newsletter

With well over a billion cars worldwide, electric vehicles are still only a small percentage. An economist from the University of Michigan Energy Institute says that is likely to change. Maskot / Getty Images

In 2018, there were about 5 million electric cars on the road globally. It sounds like a large number, but with well over a billion cars worldwide, electric vehicles are still only a small percentage.

Read More
Nestlé is accelerating its efforts to bring functional, safe and environmentally friendly packaging solutions to the market and to address the global challenge of plastic packaging waste. Nestlé / Flickr / CC BY-NC-ND 2.0

Nestlé, the world's largest food company, said it will invest up to $2 billion to address the plastic waste crisis that it is largely responsible for.

Read More
Sponsored
Determining the effects of media on people's lives requires knowledge of what people are actually seeing and doing on those screens. Vertigo3d / iStock / Getty Images Plus

By Byron Reeves, Nilam Ram and Thomas N. Robinson

There's a lot of talk about digital media. Increasing screen time has created worries about media's impacts on democracy, addiction, depression, relationships, learning, health, privacy and much more. The effects are frequently assumed to be huge, even apocalyptic.

Read More
Indigenous people of various ethnic groups protest calling for demarcation of lands during the closing of the 'Red January - Indigenous Blood', in Paulista Avenue, in São Paulo, Brazil, Jan. 31, 2019. Cris Faga / NurPhoto / Getty Images

By Raphael Tsavkko Garcia

Rarely has something so precious fallen into such unsafe hands. Since Jair Bolsonaro took the Brazilian presidency in 2019, the Amazon, which makes up 10 percent of our planet's biodiversity and absorbs an estimated 5 percent of global carbon emissions, has been hit with a record number of fires and unprecedented deforestation.

Read More
Microsoft's main campus in Redmond, Washington on May 12, 2017. GLENN CHAPMAN / AFP via Getty Images

Microsoft announced ambitious new plans to become carbon negative by 2030 and then go one step further and remove by 2050 all the carbon it has emitted since the company was founded in 1975, according to a company press release.

Read More