Thursday, February 10, 2011

New Madrid Seismic Zone may have passed its energy on to other faults

Mian Liu on the site of May 2008 Wenchuan earthquake in Sichuan.
A new study suggests that the New Madrid Seismic Zone may not be as active as previously thought.

The study looked at 2,000 years of documented earthquakes in Northern China. Northern China is similar to the Midwest because it sits far from a plate boundary, yet still experiences frequent earthquakes.

It turns out that none of the Northern Chinese fault lines produced more than one earthquake during the 2,000 year period. According to one of the study’s co-authors, Mian Liu, a University of Missouri geosciences professor, the energy seems to move from one fault zone to another to another.

"The faults communicated with each other. Rather than looking at only one fault zone such as the New Madrid Fault Zone just because it produced an earthquake in the past, because if there is anything that we can learn from the Chinese data it’s that the large earthquakes in mid-continent migrate," Mian Liu said.

Following an earthquake, the study suggests that a mid-continental fault zone may pass through an extended period of inactivity. Meanwhile, another fault zone, perhaps 600 or 700 miles away, builds up the energy that produces the next big quake.

The study was published in the journal Lithosphere.

Jacob McCleland, KRCU
Photo courtesy of the University of Missouri


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