In these, the waning days of summer, Colorado has gotten a bit cranky.
Monday night, a 3.7-magnitude earthquake rattled Craig, in northwestern Colorado. That came a day after a 3.9-magnitude quake rolled Eads, on the Eastern Plains.
Neither caused any damage, but, taken together, the two quakes represent the most intense period of tectonic temper tantrums this year in Colorado. The shaker near Eads was the largest-magnitude quake in the state in more than two years.
“It’s pretty unusual seeing two back-to-back,” said Vince Matthews, director of the Colorado Geological Survey. “There’s nothing to indicate they’re linked. I think it’s just coincidence.”
In fact, while the state may not have seen a bruising quake in more than a century — a 6.6-magnitude quake near Estes Park in 1882 knocked out power in Denver — Colorado often sees lesser rumblers.
Put another way, if the state’s a-rockin’, it ain’t that shockin’.
There have been nine recorded earthquakes in the state so far this year, according to data from the National Earthquake Information Center in Golden.
Since 2005, the center has recorded nearly 100 earthquakes in Colorado.
What makes this week’s quakes so interesting is that they hint at the state’s tectonic mysteries. Neither occurred along mapped fault lines, although Matthews believes the Eads quake shows that the Cheraw fault in southeastern Colorado — a fault geologists say is capable of producing a 7.0-magnitude quake — is longer than thought.
Matthews hopes to wrangle funding to keep five seismographs that are part of a traveling study in the state to better understand Colorado’s subterranean scuffles.
John Ingold: 303-954-1068 or jingold@denverpost.com
