Abstract
The great New Madrid earthquakes of 1811 and 1812 were accompanied by extensive liquefaction within the meizoseismal zone. We examined tens of kilometers of freshly excavated ditch banks within the southern limb of the New Madrid Seismic Zone for evidence of prehistoric liquefaction events. Radiocarbon dates indicate that the exposures studied provide a record of the last 5000 to 10,000 years. Analyses of the statistics of historical seismicity imply a relatively short 550- to 1100-yr repeat time for 1811- to 1812-type earthquakes. In contrast, our search did not reveal definitive evidence of widespread paleoliquefaction events and, hence, provides no independent support for the relatively short 550- to 1100-yr return time implied by statistics of historical seismicity.
