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2015 another record year for quakes in Oklahoma

A 4.2 magnitude earthquake Tuesday near Edmond capped off a record year of earthquakes in the state. Now, 2016 is off to a shaky start. Just before 6 a.m Friday, the Oklahoma Geological Survey recorded a 4.2 magnitude quake near north Oklahoma City. OGS Director Jeremy Boak said he expects the trend to continue, but to what extent remains to be seen.

“We had 881 M3.0+ earthquakes for the year … With 480 in January to June, this means we had about 20 percent fewer of these earthquakes in the second half. On the other hand, we had 14 and 15 M4.0+ earthquakes in the same periods for the year, for a total of 29, more than twice last year’s total. Because the overall numbers are small, this is probably not statistically important, but it will have felt so to those near these earthquakes.”

In 2014, the state recorded 585 quakes of magnitude 3 or larger, compared with only 100 in 2013, according to federal earthquake data. California, by comparison, had fewer than one-third that number. That put Oklahoma at the top of the list for most seismically active state outside of Alaska and Hawaii, a dubious distinction it maintained in 2015.

Geologists have linked the earthquake proliferation to disposal wells used to jettison byproducts of the fracking process. Disposal wells in the Arbuckle formation receive a large portion of the wastewater, but the Oklahoma Corporation Commission has been monitoring those sites heavily and has implemented restrictions to limit capacity and usage.

“I do expect a decrease this year, but could not hope to estimate how much,” Boak said. “I suspect it will have to be substantial to reduce the pressure on the Corporation Commission.”

Related: Oklahoma oil, gas regulators order changes after earthquakes

While the Oklahoma Corporation Commission is responsible for monitoring the disposal wells in conjunction with the EPA, some legislators are calling for more action to address the issue.

“There is much more that she could and should be doing before someone is seriously injured,” Rep. Richard Morrissette (D-Oklahoma City) said. “The governor has control of the drill bit here. She has the executive authority to order a complete halt to ‘produced water’ being pumped into any more wells that inject into the Arbuckle formation, not simply a reduction in the amount injected into wells near areas that have previously experienced a quake.

“Back in March, operators of 347 wells were ordered to reduce injection outputs. In July, another 211 wells were ordered to do the same. Have we seen a reduction in ‘quakes? I think (Tuesday’s) earthquakes prove my point, and no order to cease operations has come from Fallin’s office.”

Gov. Mary Fallin’s Communication Director Michael McNutt said several steps have been taken to address the disposal well problem, but it’s not as simple as Morrisette is making it out to be.

“The governor absolutely does not have that authority,” McNutt said. “Senate Bill 809, which passed in 2015 emphasizes the exclusive authority of the Oklahoma Corporation Commission to regulate oil and gas operations in Oklahoma. The OCC has taken an active, science-based approach to responding to earthquakes. Based on geological mapping — provided with the help and cooperation of the energy industry — the commission has acted to reduce the depths and volumes of hundreds of wells over the Arbuckle rock formation.”

At this point, the OCC and OGS are focused on the data.

“I think we are beginning to get sufficient data to determine whether reductions in injection are having an effect,” Boak said. “Timely oil production data would help confirm that possible trend.”

Moving forward, Boak said the biggest questions relate to what effect changes in injection by OCC action and a drop in oil prices will produce.

“Over the holiday, I met with some of the USGS National Earthquake Information Center team, and there is great enthusiasm there for continuing and enhancing cooperation,” Boak said. “USGS has just installed stations in the north central part of the state, and we will add some there too, so that we can better locate the earthquakes there. I still see the question of what multiple modest size earthquakes do to buildings as important going ahead.”

Ultimately, Boak said the solution might mean a big change in the future.

“We may be engaged in the search for alternative options for produced salt water disposal,” he said.

 

This article was written by Mack Burke from The Norman Transcript, Okla. and was legally licensed through the NewsCred publisher network.