ST. LOUIS – Residents of the St. Louis metro area felt the rumble of an earthquake early Thursday morning, the second quake in as many days.
The first quake occurred a little after 2 a.m. Wednesday morning near Bonne Terre, Missouri. This earthquake was small—a magnitude of about 2.5—so it wasn't really felt by anybody. But there was an instrument within 10 miles of the earthquake, so there was a good recording and data for scientists to analyze. That earthquake was three miles deep.
The most recent earthquake was stronger—a 3.7 magnitude—and was felt by some in the St. Louis metro.
Thursday’s quake happened at 1:42 a.m. and was centered in north-central Arkansas, near the Missouri state line, halfway between New Madrid and Springfield. Earthquakes in this area are somewhat rare but do occur. There have been about three quakes over the last 10 years that were good shakers.
Bob Herrmann, a professor of geophysics at Saint Louis University, said earthquake activity isn't increasing in our area. He said it's actually been quiet and the last big shaker was in April 2008 in southeast Illinois.
Earthquakes of magnitude 3.0 and up are widely felt. At magnitude 5.0, buildings will begin to see damage; but it depends on how close the buildings are to the quake’s epicenter. The last big quake in April 2008 had a magnitude of about 5.3 and damaged some buildings.