Oklahoma rattled by state’s third-largest earthquake; 5.1 recorded near Fairview

Tulsa World – by Paighten Harkins

The third-largest earthquake in recorded state history rocked parts of western Oklahoma on Saturday morning near the site of other large, recent temblors.

The quake registered a 5.1 magnitude and was recorded northwest of Fairview at 11:07 a.m., according to preliminary estimates from the U.S. Geological Survey.

A 3.9 aftershock followed about 10 minutes after the earthquake, according to the USGS.

At 5.1, the temblor will be the state’s third-largest earthquake, according to Oklahoma Geological Survey data.

The state’s largest earthquake is a 5.6 recorded out of Prague in 2011. The second was a 5.5 recorded near El Reno in 1952. Before Saturday, those two were the only quakes in state history to exceed a 5.0 magnitude.

Saturday’s quake surpassed a 4.8 recorded on Jan. 6 for this year’s largest earthquake. Both the 4.8 and Saturday’s 5.1 were centered near Fairview, according to USGS data.

The Oil and Gas Conservation Division of the the Oklahoma Corporation Commission on Tuesday is scheduled to release details of a large regional plan to address the continuing earthquakes in such areas as Fairview, Cherokee, Medford and elsewhere in the western region, according to a release from the commission.

The plan will involve a large-scale regional reduction in oil and gas wastewater disposal for an approximately 5,000-square-mile-area in western Oklahoma, the release states. It will affect more than 200 Arbuckle disposal wells; researchers agree that disposal wells injecting into the Arbuckle formation pose the highest potential risk for causing damaging earthquakes in Oklahoma, according to the release.

All the major work on the plan has been completed, and notification of disposal well operators began Thursday, according to the release.

Before Saturday, Oklahoma had been shaken by seven earthquakes of at least 4.0 magnitude in 2016. Those quakes were all recorded within the first eight days of January.

The strongest of those — the 4.8 on Jan. 6 — was among a swam of 32 earthquakes recorded over a period of about 24 hours.

Through Friday evening, Oklahoma had recorded 133 quakes this year that measured at least 3.0, according to the Oklahoma Geological Survey.