SALT LAKE CITY (AP) — A University of Utah study had rejected a company's claims concerning the cause of a 2007 collapse at Utah's Crandall Canyon coal mine that killed nine people.
The scientists presented findings of their research Friday at the Seismological Society of America's annual convention Friday in Salt Lake City.
The research turned up hundreds of previously unknown foreshocks and aftershocks that indicate the size of the implosion was greater than previously thought, The Salt Lake Tribune reported (http://bit.ly/ZA6WEo ).
The scientists found "strong statistical evidence" of 569 aftershocks to go along with 759 seismic events that preceded the August 2007 collapse, which registered as a magnitude-3.9 earthquake.
Murray Energy Co. chief Bob Murray has insisted that the cave-in at the mine co-owned and operated by his company was triggered by a natural earthquake — and a company statement released Friday reaffirms that position.
But university spokesman Lee Siegel said the study does not support that view.
"(Murray Energy's) statement is not based on science and is divorced from reality," Siegel said. "From the day of the Crandall Canyon mine collapse, University of Utah Seismograph Stations pointed out the magnitude-3.9 seismic event recorded was not a natural earthquake, but in fact was the seismic signal of the mine collapse itself. The new study and a 2008 university study both reinforce that view, contrary to (Murray Energy's) claim."
The collapse instantly entombed six miners nearly a half-mile underground. Their bodies have never been recovered. Another cave-in 10 days later killed two rescuers and a federal inspector during a frantic effort to tunnel their way to the trapped miners.
The new research shows the foreshocks and aftershocks were clustered in three areas: where the buried miners were working, where the rescuers were killed and in the mine's western depths.
In 2012, Murray Energy paid nearly $1.5 million to resolve criminal charges and mine-safety citations.
Information from: The Salt Lake Tribune, http://www.sltrib.com