Area hit by 3.5-magnitude quake

A 3.5-magnitude earthquake shook extreme northwest Colorado on Saturday morning, alarming residents in the town of Rangely.

“It felt like an explosion, honestly,” said Miranda Hayes, a Rangely Police Department dispatcher. “Everything in the office rattled and shook. It just felt like — I don’t know, it was scary.”

The U.S. Geological Survey in Golden confirmed the quake, which happened at about 11 a.m. just outside of Rangely. It was at a depth of about 3.7 miles.

Hayes said there were no reports of serious damage in Rangely — a town of about 2,000 people that’s 90 miles north of Grand Junction — although some business had alarms going off. One business, she said, reported having some broken glass.

“My phone lines lit up after it happened,” Hayes said. “People wanted to know. It was felt from one end of town to the other. It was definitely something people heard and felt.”

USGS geophysicist John Bellini said the agency reviewed the earthquake. Quakes aren’t unusual on the Western Slope, he said, although Saturday’s was a bit stronger than others.

“The western part of the state is the part that gets the most earthquakes,” he said. “It’s not a very large earthquake. It’s large enough for people to feel over the local area there. Maybe large enough to knock some really tipsy items off the shelves.”

Bellini said the USGS doesn’t know what caused the earthquake. It happened in an area of the state that has oil and gas drilling operations, which have been linked to quakes.

“We can’t tell if an earthquake is caused by drilling or because of the normal seismicity,” he said.

The USGS forecasts that induced seismicity — quakes caused my man-made activities — poses a high hazard this year in the Colorado/ New Mexico area known as the Raton Basin, around Trinidad. The agency says, “There is a significant chance that damaging levels of ground motion will occur in 2017.”

The USGS says wastewater disposal is the primary cause of induced seismicity.

Most of Colorado — except for the San Luis Valley area — is said to have a slight risk of having an earthquake this year. Jesse Paul: 303-954-1733, jpaul@denverpost.com or @JesseAPaul