On the Search for Paleoliquefaction in the New Madrid Seismic Zone

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Abstract The great 1811–12 New Madrid earthquakes produced extensive liquefaction in the meisoseismal zone, which is largely within the St. Francis drainage basin of Missouri and Arkansas. We examined 10’s of kilometers of ditch banks within the meisoseismal zone for evidence of prehistoric liquefaction events. Radiocarbon dates indicate that the exposures studied provide a record of the last 5,000 to 10,000 years. Our search has revealed no evidence of widespread paleoliquefaction events and, hence, provides no independent support for the relatively short 550 to 1100 year return time of 1811–12 type earthquakes implied by analyses of the statistics of historical seismicity.