USGS study: 7-magnitude earthquake could destroy Memphis and Little Rock

Computer simulations of earthquake shaking, replicating the quakes that occurred in 1811-1812 in the New Madrid seismic zone (NMSZ), indicate that future large earthquakes there would produce major, prolonged ground shaking. The 1811-1812 events were some of the largest in the United States since its settlement by Europeans, and the NMSZ spans portions of seven states: Illinois, Indiana, Missouri, Arkansas, Kentucky, Tennessee and Mississippi.

Scientists from the Universidad Nacional Autónoma de México, the U.S. Geological Survey, San Diego State University, AECOM (formerly URS Corporation), and the University of Memphis simulated a set of 20 hypothetical, yet plausible earthquakes located along two currently active faults in the NMSZ. The hypothetical earthquake scenarios range in magnitude from 7.0 to 7.7, and consider various possible epicenters.

“Based on our simulations, were the 1811-1812 earthquakes to repeat today, more than 8 million people living and working near the New Madrid seismic zone would experience potentially damaging ground shaking at modified Mercalli intensities ranging from VI to VIII,” said Leonardo Ramirez-Guzman, lead author of the paper that appears in the July 30 edition of the Bulletin of the Seismological Society of America.

“Strong ground shaking in the greater Memphis metropolitan area could last from 30 seconds to more than 60 seconds, depending on the magnitude and epicenter of a potential seismic event,” said Ramirez-Guzman, a professor at Universidad Nacional Autónoma de México and former USGS contract scientist.

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