Arkansas is now seeing a ton of earthquakes in what is the continuation of an “earthquake swarm” that has been occurring over the past couple of years. The cause is unknown, but could very well be from hydraulic fracturing (or fracking) in the area. Additionally, this was a leading possibility for why the area saw mass bird and fish deaths last month (click link above).
Recent Arkansas Earthquakes
“Several small earthquakes ranging in magnitude from 1.8 to 3.8 have rattled the north-central Arkansas cities of Greenbrier and Guy this week, and the cause is unknown,” the Associated Press wrote yesterday.
More earthquakes struck last night, “including a preliminary magnitude 4.0 quake in central Arkansas and a 3.2 magnitude tremor in the eastern part of the state,” KY3 reports. A dozen more earthquakes have struck today, the biggest of which was a magnitude 4.3.
Over 700 earthquakes have occurred in this region in the last six months, a few dozen or more this week.
Earthquakes Could Be from Fracking, Geologists Think
Geologists are still trying to figure out the cause of all the earthquakes that have been hitting this region in the last couple of years, but they have two basic theories at this point.
“It could just be a naturally occurring swarm like the Enola swarm, or it could be related to ongoing natural gas exploration in the area,” Scott Ausbrooks, geohazards supervisor for the Arkansas Geological Survey, said.
Yes, that would be fracking.
The geologists don’t think it’s the production wells, “but rather the injection wells that are used to dispose of ‘frack’ water when it can no longer be re-used.” The earthquakes are all happening near several injection wells. Local officials are now studying this theory:
Lawrence Bengal, director of the Arkansas Oil and Gas Commission, said a six-month moratorium was established in January on new injection wells in the area. He said four companies are operating already-drilled injection wells: SEECO Inc., Chesapeake Operating Inc., Clarita Operating LLC and Deep-Six Water Disposal Services LLC.
The moratorium, which is expected to end in July, is intended to allow time to study the relationship – if any – between the injection wells and earthquakes in the area.
Despite this moratorium, a disposal well in the area of these earthquakes started getting used to a greater degree recently, and is suspected by locals to be possibly causing the current swarm of quakes.
Up until this week the largest magnitude earthquake in this swarm was a magnitude 4.0 in October.
I’ll share with you again the map from last month on where the earthquake swarms were happening and where the mass bird and fish deaths were:
Arkansas map via ProAmLib