By Julie Bierach, KWMU
SAINT LOUIS, MO – U-S earthquake experts say all the available evidence shows that the cause of the mine collapse in Utah was not due to an earthquake as mine officials are claiming.
Keith Koper is a seismologist at St. Louis University. Although he hasn't seen the exact data, he tends to agree with government geologists. Usually, he says, a minor earthquake of a magnitude of 3.9 like the one in Utah usually can't be felt. "It wouldn't cause really strong ground shaking and so it seems unlikely that it could lead to the collapse of a mining tunnel," Koper said.
There are many ways scientists can determine for certain whether the seismic activity was caused by an earthquake. One of which, according to Koper, is to examine the direction of lines recorded by seismometers in the area.
"So, if you have really good data from a lot of seismometers in the area you can look at all these first motions of all the squiggly lines and that can clue you in as to whether you had an explosive or an implosive or even an earthquake source," said Koper.
Koper says the aftershocks being reported could be evidence that an earthquake did occur, but seismologists have attributed that to settling from the collapse. Seismic activity not caused by an earthquake is recorded all the time in St. Louis. Back in April both St. Louis University and Washington University recorded the detonation of the Tamm Ave. bridge.