Utah avalanche was largest in modern history

Before you go, we thought you'd like these...
Utah avalanche was largest in modern history
Matt Lengerich, from the Kennecott Utah Copper Bingham Canyon Mine speaks with the reporters during a media tour Thursday, April 25, 2013, at the Kennecott Utah Copper Mine, in Bingham Canyon, Utah. The chief of Kennecott Utah Copper guided media to the rim of Bingham Canyon Mine for a view of a massive landslide that stopped operations April 10 when 165 million tons of rock and dirt ran down a wall of the open pit. (AP Photo/Rick Bowmer)
A two-story high haul truck, lower right, travels an upper road around of Kennecott's mine Monday, June 2, 2003, in Bingham Canyon, Utah. The mine reduced an 8,000 foot high mountain to the world's deepest man-made hole. (AP Photo/Douglas C. Pizac)
Kennecott copper mine - Utah
This April 25, 2013, photo, shows a shovel working at the Kennecott Utah Copper Bingham Canyon Mine during a media tour, in Bingham Canyon, Utah. About a third of 270 eligible workers are willing to take an early retirement offer from Kennecott Utah Copper Corp. following a landslide that damaged an ore pit west of Salt Lake City. Union officials released the number Friday, May 31, 2013 to The Associated Press. The company didn't have its own estimate. Kennecott has given workers in their 50s and older until Saturday to accept or reject a $20,000 early retirement bonus and take a pension and health insurance benefits. (AP Photo/Rick Bowmer)
The Kennecott Utah Copper Bingham Canyon Mine is shown during a media tour Thursday, April 25, 2013, following a April 10, landslide, in Bingham Canyon, Utah. The chief of Kennecott Utah Copper guided media to the rim of Bingham Canyon Mine for a view of a massive landslide that stopped operations April 10 when 165 million tons of rock and dirt ran down a wall of the open pit. (AP Photo/Rick Bowmer)
Mining equipment damaged from the Bingham Canyon copper mine wall slide is seen in this aerial photograph taken in Bingham, Utah, U.S., on Friday, April 12, 2013. The wall slide at Rio Tinto Group?s Bingham Canyon copper mine in Utah, a site that produces about 200,000 metric tons annually, could wipe out a forecast surplus for the metal for this year, UBS AG said. Photographer: George Frey/Bloomberg via Getty Images
A building damaged from the Bingham Canyon copper mine wall slide stands in this aerial photograph taken in Bingham, Utah, U.S., on Friday, April 12, 2013. The wall slide at Rio Tinto Group?s Bingham Canyon copper mine in Utah, a site that produces about 200,000 metric tons annually, could wipe out a forecast surplus for the metal for this year, UBS AG said. Photographer: George Frey/Bloomberg via Getty Images
of
SEE ALL
BACK TO SLIDE
SHOW CAPTION +
HIDE CAPTION


SALT LAKE CITY (AP) - 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.

"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.

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.

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.
Read Full Story

People are Reading