Most think of California or the West Coast as the likely source for an earthquake. But as rare as they are to North Georgia and southeastern U.S., earthquakes can happen here, and their effects can be felt from far away, as residents found out Friday night. A Friday evening quake measured 4.1 on the Richter scale, downgraded from an original reading of 4.4, and was centered about 7 miles west-northwest of Edgefield, S.C., not far from Augusta, according to the U.S. Geological Survey website.