University of Utah advisory
No evidence that quake triggered cave-in
Ambiguous, preliminary evidence indicates that a coal mine cave-in that trapped six miners early Monday in Utah generated seismic waves that were recorded as a magnitude-3.9 earthquake, according to the University of Utah Seismograph Stations.
There is no evidence that the earthquake triggered the mine collapse, says Walter Arabasz, director of the Seismograph Stations.
Some news media are reporting incorrectly that the quake triggered the mine collapse, apparently because the cave-in first was reported about an hour after the quake.
The magnitude of the quake was revised to 3.9, slightly smaller than the earlier estimate of 4.0, Arabasz says. The quake at 2:48 a.m. MDT was centered near the Crandall Canyon coal mine, where six miners were trapped by the cave-in. The mine,formerly owned by Genwal Resources, Inc., is now owned by UtahAmerican Resources, Inc.
Arabasz said the seismic wave patterns from the quake appear consistent with the idea that the mine collapse was the source of seismic waves recorded as the earthquake. There is a long history of earthquakes being generated by collapses in mines in Utah and elsewhere.
Editor's note: It is not clear at press time whether the quake caused the cave-in or the cave-in caused the quake. In an effort to tell both sides of the story, the mine believes the quake caused the cave-in and the University of Utah believes the cave-in caused the earthquake. That doesn't matter to me, what caused what, the important thing here is that six men are trapped and their lives are threatened. Their safe return is all that counts.