Wyo. Mine Blast Picked Up On Seismographs

GILLETTE, Wyo. (AP) — An explosion at a coal mine northeast Wyoming was big enough to register on seismographs on the scale of a small earthquake.

Some people in Gillette reported feeling the ground shake from 16 miles away.

The U.S. Geological Survey recorded the blast at 11:11 a.m. Tuesday. The blast registered as large as a magnitude 4.5 earthquake but had the signature of a human-caused explosion.

The Associated Press reports using explosives is a routine part of remove dirt and soil at the coal mines where the blast occurred southeast of Gillette.

The explosion happened in the area of Cloud Peak Energy's Cordero Rojo mine.

Mine explosions that register with such force are rare. Sheriff's officials said they had not heard of any emergency at the mines.