U.S. Geological Survey

4.6-magnitude earthquake strikes in Colorado, southeast of Moab

By Jacob Klopfenstein, KSL.com | Updated - Mar. 4, 2019 at 6:24 p.m. | Posted - Mar. 4, 2019 at 10:46 a.m.

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BEDROCK, Colorado — A 4.6-magnitude earthquake struck Monday morning just east of the Utah-Colorado border, southeast of Moab.

The earthquake was reported 4 miles south of the tiny Colorado town of Bedrock at 10:22 a.m., according to the U.S. Geological Survey. The epicenter was located about 40 miles southeast of Moab.

The USGS initially reported the quake at a 5.3 magnitude before quickly downgrading it to 4.6. Earthquake magnitudes often take a long time to be calculated, said earthquake information specialist Mark Hale, with the University of Utah Seismograph Stations.

There have been no reports of damage or injuries, according to the Grand County Sheriff's Office.

Todd Moon, who lives in Blanding in San Juan County, said everything started bouncing and shaking when the earthquake hit.

"Things were physically moving in the entire building," Moon said. "I was literally sitting at my desk and my chair was bouncing up and down."

The shaking lasted 10 to 20 seconds, which is unusual for the Blanding area, Moon said.

The USGS has reported there is a 54 percent chance of aftershock earthquakes with magnitudes of 3.0 or higher in the area within the next week, according to the Grand County Sheriff's Office.

The quake happened near the federal Bureau of Reclamation's Paradox Valley Salinity Control Facility.

The facility injects highly pressurized brine into a 16,000-foot-deep well, Bureau of Reclamation officials said in an email. The facility helps control water quality downstream in the Colorado River watershed by preventing the brine from entering the nearby Dolores River.

Workers at the facility felt the quake on Monday morning, Bureau of Reclamation officials said. Brine injection similar to the procedure carried out at the Bedrock facility has been known to trigger small earthquakes, but the well was not operating at the time of Monday's earthquake, officials said.

The well will not resume operations until the Bureau of Reclamation assesses the situation, officials said.

Hale said every earthquake increases the chance of a larger earthquake by about 5 percent.

However, those larger quakes sometimes are only .05-magnitude stronger than the initial tremor, Hale said.

The idea that earthquakes relieve pressure to prevent a larger earthquake in the future is a myth, Hale said.

"Small earthquakes don’t really relieve the pressure for a larger quake," he said. "That’s the most important thing that we want to dispel."

The majority of injuries from earthquakes come from things inside homes falling on the occupants, according to Hale. People should make sure to secure heavy items to avoid dangerous situations in an earthquake, Hale said.

"We live in earthquake country — this is a pretty large earthquake," he said. "It’s just a good reminder for people to be prepared."

Several residents in southeast Utah reported to KSL that they felt the quake.

Contributing: Heather Kelly, Morgan Pratt, Randall Jeppesen, KSL Newsradio

Jacob Klopfenstein

KSL Weather Forecast