The New Madrid fault line has been rumbling again. An expert says a recent series of small quakes isn't unusual, but it is a reminder of what can happen with the active fault.
Four small quakes have been reported near New Madrid in southeast Missouri in the past week.
The largest was a magnitude 3.1 quake Friday that was felt in parts of Missouri, Arkansas, Tennessee and Kentucky. No damage was reported.
Robert Hermann of the Earthquake Center at Saint Louis University says a quake large enough to be felt happens about once a month in the region, and quakes with magnitude 2.0 and smaller happen on an almost daily basis.
But Hermann is careful not to downplay the rumbling because many experts fear it is only a matter of time before another big quake hits the region.