Federal seismologists, using updated geologic data and a better understanding about how the ground shakes, say that parts of Colorado may have a higher earthquake hazard than previously thought, the U.S. Geologic Survey announced Thursday.
In general, however, the hazard in the Centennial state remains fairly low and hasn’t changed drastically, according to Mark Petersen, project chief of the survey’s earthquake hazards program in Golden.
“Colorado has experienced damaging earthquakes in the past,” Petersen said. “There are historic reasons to think that there is some earthquake probability for Colorado. There are also some big faults in western Colorado.”
The updated hazard areas — centered on the Western Slope, specifically in areas between Rifle and Craig — are part of new national seismic hazard maps. The maps were updated for the first time since 2008 and “represent the best available science in earthquake hazards,” officials say.
Hazard maps are used in building codes and zoning, Petersen said.
The updated data does not take into account potentially induced earthquakes, such as those that might be caused from wastewater disposal associated with hydraulic fracturing, Petersen said.
Officials hope to have separate mapping that includes potentially induced quakes ready in about a year.
“The new models are based on two to three times more data than the old maps,” Petersen said, adding that being prepared before the ground starts shaking is key.
“(The risk) isn’t super high and we don’t experience a lot of earthquakes in Colorado,” he said. “But I think people need to be aware that we have had earthquakes in Colorado and we will have them in the future.”
Areas in 16 states — including California, Oregon, Utah, Wyoming, Washington and Nevada — have the highest risk for earthquakes, according to the report.
Jesse Paul: 303-954-1733, jpaul@denverpost.com or twitter.com/jesseapaul
The Associated Press contributed to this story.
