At approximately 6:44 a.m. Friday, Glenwood Springs experienced an earthquake that was measured at 2.9 magnitude on the Richter scale at a depth of 5 kilometers and was located approximately seven kilometers northeast of Chacra, a small town in between Glenwood Springs and New Castle. 

The earthquakes that happen around Garfield County however aren’t numerous or dangerous, ranging from around magnitude 2.5 to 5 and the maximum depth goes down to 5 kilometers. 

Friday’s earthquake is classified by the National Earthquake Information Center (NEIC) in Golden, CO as a weak earthquake, as magnitude 2-3 fits into that classification. 

The areas around Glenwood Springs have many fault lines where thermal activity bubbles beneath the surface, which is why the hot springs are available to the public.

An earthquake is a surface expression of the underground movement of a fault line. Earthquakes can be described as where the failure of the earth occurred. 

Mountains occur when tectonic plates are under compressional stress, where the plates move towards each other with the rocks and crash going up and creating ridges. Because of the forces at work, the rocks under the surface are getting crushed and they break, creating fault lines. 

There’s a series of faults in the mountains of Glenwood Springs, created millions of years ago when there was compression put on the North American plate. Now they’re strung across north of Glenwood Springs, where most of the earthquakes in the surrounding area have occurred. 

For more information on earthquakes, visit earthquake.usgs.gov/earthquakes/eventpage/us6000nzip/dyfi/intensity.