WHEN: May 8-19 and November 4-18, 2006
WHERE: Lepanto, AR on State Highway 14. Located about 42 miles NW of Memphis, TN. Also, across Crowley's Ridge between Jonesboro and Harrisburg, AR. This site was chosen because of: pre-existing data at the site that indicated a good target, proximity to the Blytheville Arch and the New Madrid seismic zone, and field acquisition logistics to make future data acquisition along this cross section feasible.
HISTORY: The study area is located at the southern end of the New Madrid seismic zone and was seriously affected by great shocks of 1811-1812. The Mississippi River valley earthquakes of 1811-1812 rank among the most significant events in U.S. history. The area of strong shaking associated with these shocks is two to three times larger than that of the 1964 Alaska earthquake and 10 times larger than that of the 1906 San Francisco earthquake.
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![](https://webarchive.library.unt.edu/web/20090902004417im_/http://earthquake.usgs.gov/regional/ceus/images/regional_location_sm.jpg)
Map of middle Mississippi River valley in the central U.S. showing topography (purple at about 47 m up to orange at about 360 m elevation). White heavy lines bound the Reelfoot rift. New Madrid seismic zone seismicity shown by white and blue circles, are evidence that earthquakes threaten the Mississippi, Ohio, and Wabash River valleys of the Central United States. Several of the largest historical earthquakes to strike the continental United States occurred in the winter of 1811–1812 along the New Madrid seismic zone, which stretches from just west of Memphis, Tenn., into southern Illinois. Black box outlines Transect study area. (Base topographic map courtesy of Robert Smalley, Univ. of Memphis.) |