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A University of Utah seismologist informed local authorities of the Aug. 6 cave-in that trapped six miners at the Crandall Canyon mine before mine officials called 911, requesting an ambulance.

Walter Arabasz made phone calls to the Emery County Sheriff's Office and the Carbon County Sheriff's Office beginning at 3:47 a.m., four minutes before the 911 call from the mine, according to police tapes obtained by the Associated Press.

An automatic paging system alerted Arabasz and his two U. colleagues, James Pechmann and Relu Burlacu, about five minutes after the 3.9 magnitude seismic event in Crandall Canyon. All seismic events greater than 2.5 magnitude in the Wasatch Front corridor and greater than 3.0 in outlying areas generate automatic pages to the seismologists.

All three checked the automatic Web posting of the event on their home computers, then came to the Seismograph Network Operations Center at the U. They verified the magnitude and location of the event, then made routine phone calls to local authorities.

"Just from the general character of the seismic event, it looks like it might be a coal-mining event," Arabasz said on the tapes, the AP reported.

However, none of the seismologists knew whether the mine had collapsed or whether a natural earthquake had occurred, Arabasz said.

"All that was apparent from the consistent downward thrust motion was that this was suggestive that this was a coal-mining related event," he told The Salt Lake Tribune on Monday.

Pechmann concurred.

"Based on our initial look, it looks like it was all downward motion, and we thought it might be a mine collapse, but it wasn't until later that we went through all the data thoroughly," Pechmann told The Tribune.

Mine co-owner Robert Murray has maintained that a naturally occurring earthquake caused the collapse of the mine, though seismologists say the magnitude and shallow depth of the seismic event show a mine collapse causing the tremor.

The two U. seismologists were accustomed to seeing seismic events near long-wall mines, where coal is extracted and the roof caves in.

However, those events usually register somewhere in the 2.0 range of magnitudes, Pechmann said.

"What we observe remotely seismologically we can only explain when we have independent information from the mine," said Arabasz, who added that information was not readily available on Aug. 6.

While part of the reason for the phone calls was to alert local authorities, Arabasz also wanted to gather any other information, such as if anyone had felt the tremor or if injury reports had come through yet. When Arabasz called, authorities had not yet received calls.

The Carbon County Sheriff's Office later called Arabasz and informed him that the seismic event was indeed mine-related, and that the Crandall Canyon mine had collapsed.

"With that phone call came the closure of our need to notify or gather any more information," Arabasz said.