12 earthquakes shake Faulkner county Arkansas in 24 hour period

February 16, 2011 – GUY, ARK – People who live in northern Faulkner County are feeling the ground shake again. 12 earthquakes have happened in the Greenbrier area between 3:30 this morning and 3:30 this afternoon. The strongest of those registered 2.9 on the Richter Scale. There have been a dozen quakes since Monday around Greenbrier according to the United States Geological Survey (USGS). According to Wikipedia, earthquakes that register 2.0 to 2.9 in magnitude are classified as minor and are generally not felt. There are about 1,000 of these everyday around the world. –Arkansas Matters

Update quake swarm intensifies – 3.8 quake rattles Arkansas – LITTLE ROCK, Ark. (AP) — Jim Sutterfield was briefly puzzled by a thumping sound that seemed to slam the back of his office chair. But when the small-town Arkansas fire chief turned and saw no one was around, he quickly realized it was just an earthquake — again. “That was only my second time to feel one, but others here have felt them for three or four months now,” Greenbrier chief Jim Sutterfield said after feeling the latest tremor on Wednesday. “Now when it happens, people say, ‘Well, there’s another one.'” Several small earthquakes ranging in magnitude from 1.8 to 3.5 have rattled the north-central Arkansas cities of Greenbrier and Guy this week, and the cause is unknown. The U.S. Geological Survey has reported 29 earthquakes in the area since Sunday, with 16 of them occurring Wednesday, two of which were magnitude 3.2 and 3.5. More than 700 quakes have occurred in the region over the past six months. Ausbrooks said geologists are still trying to discover the exact cause of the recent seismic activity but have identified two possibilities. “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,” he said. –Bloomberg