Liquefaction Evidence for Repeated Holocene Earthquakes in the Coastal Region of South Carolina a

Features thought to have originated from earthquake-induced liquefaction have been discovered throughout much of the coastal region in South Carolina and in extreme southeastern North Carolina. Nearly all these liquefaction features are sandblows presently manifested as filled craters. Prehistoric craters near Charleston formed in long-separated episodes at least three times within the past 7200 years. Ages of dated craters far from Charleston, beyond the farthest 1886 earthquake sandblows, differ from ages of craters near Charleston. Insufficient data have been collected to determine whether ages of all craters far from Charleston differ from ages of craters near Charleston. Both the size and relative abundance of pre-1886 craters are greater in the vicinity of Charleston (particularly in the 1886 meizoseismal zone) than elsewhere, even though the susceptibility to earthquake-induced liquefaction is approximately the same at many places throughout this coastal region. These data indicate that, in this coastal region, the strongest earthquake shaking during Holocene time has taken place repeatedly near Charleston.