nb_cid nb_clickOther -tt-nb this.style.behavior='url(#default#homepage)';this.setHomePage('http://www.aol.com/?mtmhp=acmpolicybanner072814 network-banner-promo mtmhpBanner
14
Search AOL Mail
AOL Mail
Video
Video
AOL Favorites
Favorites
Menu

Utah avalanche was largest in modern history



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.

Join the discussion

1000|Char. 1000  Char.
woodytmartin January 08 2014 at 10:21 AM

Must have saved them a lot of work digging that rock!

Flag Reply +1 rate up
HAT1701D January 08 2014 at 4:34 PM

Wait a minute.....This is the biggest landslide in modern history. Then in the article "The 1980 eruption of Mount St. Helens in Washington unleashed a landslide 57 times larger than Kennecott's". 1980 is modern history.

Flag Reply +10 rate up
1 reply
mdenviron HAT1701D January 08 2014 at 5:01 PM

I was a freshman in high school that year...seems like ancient times now...Go Chargers!

Flag Reply +1 rate up
muchamucha January 08 2014 at 9:21 AM

How is this a disaster? No human life was lost and Kennecott continually keeps burying themselves deeper. Not only into a single mountain but over the years the operation now encompasses half a mountain range. They make so much G*d Da%n money it didn't make a dent in their output.
This is an open pit mine that will NEVER EVER be put back to its natural contours. I am from Utah and fly over that eye sore every time I fly into SLC intl airport. It keeps getting bigger and the lake keeps shrinking. THIS IS NOT A DISASTER this is an ecological travesty!

Flag Reply +4 rate up
Janet January 08 2014 at 9:07 AM

I believe that Utah had this designated a National Monument some years back, so what does Kennicott care. They have polluted and destroyed the towns all around it and are now ready to leave anyhow. These are just my beliefs, as they are (until they sold to another company) going to pollute our Lake Superior with their sulfide mining under a river only nine miles away from the lake.

Flag Reply +6 rate up
MICHAEL January 08 2014 at 8:59 AM

thats what happens when you dig a big a** hole in the ground. its called gravity. the top will eventually slide to the bottom.

Flag Reply +8 rate up
jpaf January 08 2014 at 5:03 PM

This former geology teacher, used to alway relate the story of Krakatoa to the students. Sure hope something like that never happens again, but, I also am well aware that it surely will due to the plate activities. Afterall, even Northern NJ was formulated due to seismic actions (pre-Dinosaur days). My graduate thesis project was dealing with 'proving' plate tectonics - yeah, it was a longtime ago, in our terms, but that previous conjecture is now, without doubt, a fact. thus, the quakes will happen and we will get caught without ability to stop.

Flag Reply +3 rate up
jcajunque January 08 2014 at 5:09 PM

Man made earthquakes. Engineers should have used their math skills a bit more when trying to figure whether or not it would be safe to dig down so deep and at what angle. Maybe work on a better system to help keep the terraces in place.

Flag Reply +4 rate up
sedegolf January 08 2014 at 11:04 AM

That Mine was there over 60 years ago and the entire hole was not manmade.

Flag Reply +1 rate up
1 reply
bhallbrown sedegolf January 08 2014 at 11:33 AM

"The entire hole was not manmade"? Sedegolf, that is an ignorant statement.

Flag Reply 0 rate up
1 reply
Majors bhallbrown January 08 2014 at 12:07 PM

It is a natural canyon, do ya homework!

Flag 0 rate up
steve January 08 2014 at 11:06 AM

how cool is it that they took all that rock to new York just to see how deep they could bury central park

Flag Reply +8 rate up
4 replies
Rich January 08 2014 at 8:29 AM

The headline says Largest Avalanche in Modern History, the 2nd to last paragraph of the story says Mount St. Helens landslide was 57 times larger. Are events that happened in 1980 no longer modern history??

Flag Reply +16 rate up
3 replies
aol~~ 1209600

Voting...

More From Our Partners