Seismologists measure fatal rock slide in Rockville

Posted at 6:07 PM, Dec 15, 2013
and last updated 2013-12-15 20:08:45-05
Before and after photo.

Before and after photo.

ROCKVILLE, Utah – Seismologists from the University of Utah recorded the size and magnitude of the rock slide that killed two people inside their home Thursday.

Jeff Elsey and Maureen Morris were killed after the boxcar-size boulder flattened their cabin in Rockville.

Seismologist Jim Pechmann said the slide was equivalent in size to a magnitude 0.4 earthquake. A quake of that size is one that normally wouldn’t be felt.

Pechmann said the comparison to an earthquake’s magnitude may not offer much insight due to the different nature of the events, but he said it is clear the rock slide came down with great force, as it crushed the home it hit.

Pechmann said rock slides can be caused when rocks start to erode away and become destabilized.

“You have a lot of freeze-thaw cycles going on, and water gets down in the rock and freezes and expands and as that goes on over time it can pry blocks of rock loose that will then fall down the cliff,” he said.

The home that was hit was in the middle of a high hazard zone. Neighbors in the area have been evacuated and will have to stay out for at least two weeks.