Updated March 30, 2011 at 10:29 p.m.
Steamboat Springs A rare earthquake shook Routt County early Wednesday, but there have not been reports of anyone feeling it.
Colorado State Geologist Vince Matthews said the 2.8-magnitude quake happened at 6:19 a.m. about 15 miles south/southwest of Howelsen Hill at a fold in the rock layers at Tow Creek in the Twentymile Park area. The location’s margin of error is plus or minus six miles.
Matthews said he had spoken to the geologist at Twentymile Coal Co., and he didn’t feel it.
“If it’s that small, you’re not going to have people feel it,” Matthews said.
Earthquakes of that magnitude rarely cause damage.
Wednesday’s earthquake was measured as occurring 1 kilometer below the surface. This led Matthews to think that the earthquake could have been triggered by mining activity.
“There are a number of faults that cut across that anticline, so it could certainly be a natural earthquake,” Matthews said.
The last time an earthquake was reported in Routt County was April 30, 2008. The 2.8-magnitude quake happened at 4:19 a.m. and was estimated to have been three miles underground about three miles southwest of Steamboat Springs.
The last earthquake strong enough to be felt by Steamboat residents happened just before midnight Oct. 9, 2005. It had a magnitude of just 2.2, but Steamboat residents were attuned to the earth shaking that night because just 10 days earlier, the valley was shaken by a 4.4-magnitude quake. The Sept. 30, 2005, quake prompted 180 calls to the county’s 911 center in the first hour after it shook buildings. Many people reported thinking a car had struck their homes. Before that quake, the last widely noticed earthquake was in February 2000.
— To reach Matt Stensland, call 970-871-4247 or email mstensland@SteamboatToday.com