A large-magnitude earthquake in the central part of the United States would jolt Tennessee and do far more damage here than another similar-sized quake out west could do to California, a Memphis geologist said.
That’s because Tennessee and California have different type terrains and that makes all the difference, said Gary Patterson with the Memphis-based Center for Earthquake Research and Information.
“If you take the same magnitude earthquake in the central United States in Tennessee versus California then the one in Tennessee will be felt over a five to 20 times larger area. You get more bang for your buck,” Patterson said.
“The deep geology here is much different. We are talking 10 to 20 miles deep here. Compared to California, the deep geology here we have is hard, cold dense rocks that transmit seismic energy and vibrations very efficiently. The vibrations go out over huge areas. In California the deep rocks are relatively hot and shattered. The seismic energy dissipates quicker.”
People as far away as Dallas, Texas and Tampa, Florida, for instance, felt a recent 4.4 magnitude quake that originated in Decatur, Tennessee Patterson told The Tennessee Star.
“The Virginia earthquake that damaged the Washington Monument several years ago was felt in Memphis. But when you have a big earthquake in Los Angeles it is barely felt 300 miles away,” Patterson said.
As The Star reported, a series of high-magnitude quakes that originated in the central part of the United States wrecked Memphis in 1811 and 1812. Those quakes started along the New Madrid Fault line in Missouri. Their reverberations rattled church bells as far away as Boston, Mass.
Also as reported, far fewer people lived in Memphis and its surrounding regions in the early 19th century. With more people living in this part of the country in the modern age comes more potential for damage and more potential deaths and injuries.
Patterson said CERI owns and operates most of the seismic instruments in the central part of the United States.
The federal U.S. Geological Survey funds CERI to maintain and operate more than 140 seismic instruments in 13 states.
As reported, Tennessee also lies along the East Tennessee Seismic zone. A minor earthquake centered in East Tennessee recently reverberated into four surrounding states.
Patterson said CERI also uses more than 40 high-quality instruments for East Tennessee.
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