 "Photo: Lennie Mahler")
As officials conceded Sunday that six miners trapped underground by a mine cave-in could be permanently lost inside the still-shifting mountain, U seismologists continue to insist that an earthquake did not trigger the collapse.
Rescue efforts to save six miners trapped by the original Aug. 6 collapse were halted last Thursday after a cave-in killed three rescue workers and injured six others who were attempting to reach the miners.
While owners of the Crandall Canyon mine say an earthquake is responsible for the mine's initial collapse and subsequent seismic "bumps" that caused Thursday's cave-in, scientists disagree.
Kris Pankow, assistant director of the U's Seismograph Stations, said what was mistaken for a 3.9-magnitude quake appears to have been the mine caving in on itself -- not a natural shift in the earth.
"What probably happened is that you had coal pillars collapse," Pankow said. "The data is not consistent with an earthquake."
She said subsequent smaller seismic "bumps" that have crippled rescue efforts are likely redadjustments in the mine.
"The mountain continues to be active, continues to move," Richard Stickler, head of the federal Mining Safety and Health Administration, told The Associated Press on Sunday. "As the weight causes pillar failures in one area of the mine, then that weight is shifted to adjacent pillars, and that process seems to be migrating out from the original area where the bump activity started."
The U's stations reported that the "bump" was likely not a tectonic shift because it was too shallow -- about one-tenth of a mile deep -- while actual earthquakes are much deeper.
Pankow said the type of seismic waves generated by activity in the monuntain also indicates that the events were the result of a mine collapse. She said shifts in the mountain have generally been downward motions, while an earthquake would generate both upward and downward movement.
The mine's co-owner, Bob Murray, lashed out at the news media the day after the initial collapse for suggesting his men were conducting "retreat mining," a method in which miners pull down the last standing pillars of coal and let the roof fall in.
"This was caused by an earthquake, not something that Murray Energy...did or our employees did or our management did," he said, his voice often rising in anger, the AP reported. "It was a natural disaster. An earthquake. And I'm going to prove it to you."
He said a quake must have caused the collpase because no mine operations were being performed within a mile of the site.
While Pankow said she has no information about practices within the mine, she said the location of the collapse is uncertain because seismograph stations that recorded the impact were not located close enough to the mine.
In the coming weeks, she said the U stations hope to get information from the mine's owners to determine the precise time and location of the collapse.
"We don't have the full picture yet," she said.
The Associated Press contributed to this story.
