May 21, 2010
New Seismic Station at Hobbs Recording Recent Earthquakes In Benton County
Ironically after finalizing the installation of the new seismic monitoring station on March 3, two earthquakes have occurred in Benton County. The latest one occurred last night at 7:01pm and registered a 2.6 magnitude on the Richter scale and the first one occurred on April 29 at 10:52am, registering 2.5 magnitude on the Richter scale just 8 weeks following the completion of the station. Both of these earthquakes occurred along or near what is referred to as the Bella Vista Fault with both epicenters near or just south of the Northwest Arkansas Regional Airport. This fault line and the one that runs through a significant portion of the Hobbs (known as the Fayetteville/Green Mountain/Glade Fault – Fayetteville being the most common name) are the two dominant fault lines through parts of Washington and Benton County.
Scientists are indicating that these events are not too unexpected, but unusual, especially being so close in time frame. The Fayetteville Fault traverses from Fayetteville entering Beaver Lake along the upper White River section; traveling along the historic river bed; leaving the lake at the saddle formed at Pine Creek Hollow and Van Winkle Hollow; reentering the lake at the Van Winkle Hollow arm; and traveling east traversing under the Beaver Lake dam. The Fayetteville Fault traverses through the park at the large saddle location (Pine Creek Hollow and Van Winkle Hollow) and along the Van Winkle arm of Beaver Lake.
The seismic station is a cooperative project between Hobbs State Park – Conservation Area, Arkansas Geological Survey and the University of Memphis.
See graphs from our monitoring station for these two events or look on-line at this link http://folkworm.ceri.memphis.edu/heli/heli_bb_ag/ and http://earthquake.usgs.gov/earthquakes/states/index.php?regionID=2.