THE SEARCH FOR EVIDENCE OF LARGE PREHISTORIC EARTHQUAKES ALONG THE ATLANTIC SEABOARD

The spacial distribution of seismically induced liquefaction features discovered along the Atlantic seaboard suggests that during the last 2000 to 5000 years, large earthquakes (body wave magnitude, m(b) greater-than-or-equal-to 5.8 +/- 0.4) in this region may have been restricted exclusively to South Carolina. Paleoliquefaction evidence for six large prehistoric earthquakes was discovered there. At least five of these past events originated in the Charleston, South Carolina, area, the locale of a magnitude 7+ event in 1886. During the past two millennia, large events may have occurred about every 500 to 600 years.