Share

Utah Avalanche Was Largest in Modern History

Paul Foy
Published: January 9, 2014

SALT LAKE CITY — The avalanche near Salt Lake City last year that carried enough rock, dirt and debris to bury New York's Central Park under 66 feet of rubble was North America's largest such disaster in modern history, according to University of Utah scientists.

The April 2013 rockslide sent 165 million tons of debris into a nearly mile-deep pit where it cracked bedrock and triggered unprecedented earthquakes, the researchers said in a newly published study.

(MORE: Salt Lake City Forecast)

"We don't know of any case until now where landslides have been shown to trigger earthquakes," said Jeff Moore, assistant professor of geology and geophysics.

This April 11, 2013, file photo, shows the Kennecott Utah Copper Bingham Canyon Mine after a landslide in Bingham Canyon, Utah. The avalanche near Salt Lake City was North America's largest such disaster in modern history. (AP Photo/The Deseret News, Ravell Call, File)

There were no injuries or deaths as the slide temporarily shut down a copper mine, burying 14 giant haul trucks and leading to a series of layoffs and buyouts at Kennecott Utah Copper Corp.

"It was a creeping movement that had been developing over many months along an old fault line," Moore said Tuesday. Kennecott had been monitoring the area and evacuated workers ahead of the danger, he said.

The disaster didn't involve a volcanic explosion and was actually a pair of related slides about 90 minutes apart, said Moore, who co-authored the study together with Kris Pankow, associate director of the university's seismograph stations.

The peer-reviewed research was published Monday in the Geological Society of America's magazine, GSA Today.

The debris slides falling as fast as 100 mph crashed to earth with such force that they registered as magnitude-5 earthquakes and then triggered 16 smaller quakes where the bedrock cracked, Moore said.

(MORE: Skier Rescued from Utah Avalanche)

Mother Nature has put on bigger shows, the scientists noted.

The 1980 eruption of Mount St. Helens in Washington unleashed a landslide 57 times larger than Kennecott's.

Another slide about 8,000 years ago at the mouth of Zion Canyon in southern Utah was five times as large.

MORE: Avalanche Forecaster

An avalanche dog frees a person buried in the snow, on December 11, 2012, during an avalanche dogs training session near Les Deux Alpes ski resort in the French Alps. (JEAN-PIERRE CLATOT/AFP/Getty Images)


Featured Blogs

Pacific Northwest on Track for Warmest Summer on Record

By Christopher C. Burt
August 1, 2015

Another heat wave has engulfed much of the U.S. Pacific Northwest the past few days with Seattle, Washington now having observed twelve 90°+ temperatures so far this summer, an all-time record (9 such days in 1958 was the previous) and also July has been their warmest month ever observed. For some of the cities in the Northwest this has been the warmest June-July period ever measured and, barring a very cool August, will end up being the warmest climatological summer on record (June-August). Here are some details.

Guillermo Gathers Steam in NE Pacific; Invest 94L Clings to Life

By Dr. Jeff Masters
July 31, 2015

Hurricane Guillermo is stepping up its game in the Northeast Pacific, as it moves along a steady west-northwest course that could bring it near the Hawaiian Islands next week. In the Atlantic, Invest 94L shows little sign of strengthening, while in the Northwest Pacific, Tropical Storm Souledor could be approaching Japan as a strong typhoon next week.

PWS Service Interruption Update

By Shaun Tanner
June 16, 2015

The development team here at Weather Underground has been hard at work producing a new homepage! Please take a look at the sneak peek and tell us what you think!

Meteorological images of the year - 2014

By Stu Ostro
December 30, 2014

My 9th annual edition.

2013-14 - An Interesting Winter From A to Z

By Tom Niziol
May 15, 2014

It was a very interesting winter across a good part of the nation from the Rockies through the Plains to the Northeast. Let's break down the most significant winter storms on a month by month basis.

What the 5th IPCC Assessment Doesn't Include

By Angela Fritz
September 27, 2013

Melting permafrost has the potential to release an additional 1.5 trillion tons of carbon into the atmosphere, and could increase our global average temperature by 1.5°F in addition to our day-to-day human emissions. However, this effect is not included in the IPCC report issued Friday morning, which means the estimates of how Earth's climate will change are likely on the conservative side.