Study shows 100s of "new" aftershocks from 2007 US mine collapse

A study by University of Utah mining engineers and seismologists found evidence of hundreds of previously unidentified aftershocks in the wake of the Crandall Canyon mine collapse in 2007

The collapse claimed the lives of nine miners. It was initially blamed on an earthquake but Utah seismologists said that the the collapse itself that registered on seismometers.

The study's findings are puzzling because some of the newly reported aftershocks were found in an area where no mining had occurred.

Some of the tremors that occurred further away from mining activity are said to be related to rescue attempts but others remain unexplained.

Study co-author Michael McCarter says that further investigations will be held:

"Any understanding we can get toward learning how and why mine collapses happen is going to be of interest to the mining community…we are looking at the Crandall Canyon event because we have accurate logs and very extensive seismic data, and that provides a way of investigating the data to see if anything could be applied to other mines to improve safety."