Aug. 24 (Bloomberg) -- While major earthquakes on the U.S. East Coast are rare, the area around yesterday’s 5.8-magnitude temblor near Mineral, Virginia, has rocked noticeably since at least George Washington’s day.
A February 1774 quake knocked houses off their foundations in Petersburg and Blandford, suburbs of Richmond, according to the U.S. Geological Survey. The towns are about 62 miles (100 kilometers) from yesterday’s epicenter. An 1828 shock in southwestern Virginia, felt in Washington, caused President John Quincy Adams to liken it to the heaving of a ship at sea.
The earthquake yesterday, centered 38 miles northwest of Richmond and 84 miles southwest of Washington, rocked buildings as far away as Boston and prompted evacuations in the nation’s capital and in New York City.
“There was all this shaking, at first I thought something had hit the building,” said Julian Teixeira, a spokesman for the National Council of La Raza, a civil-rights group whose office is two blocks from the White House. “You don’t expect your desk to be moving and the floor to be shaking in Washington, D.C.”
The Virginia tremor is among the 1 percent of U.S. earthquakes that occur when pressure intensifies along a fault in the middle of a large piece of the earth’s crust known as a tectonic plate, said Kate Hutton, a staff seismologist at the California Institute of Technology in Pasadena.
‘Strain Builds Up’
“The strain builds up over a long time period and at some point, it breaks,” Hutton said in a telephone interview. “There’s no reason it happens at a particular time.”
The remaining 99 percent of earthquakes occur when tectonic plates shift along boundaries with each other, such as in Japan and California, she said.
“There’s much more action going on on plate boundaries,” Hutton said.
The closest plate boundaries to the central Virginia seismic zone are in the center of the Atlantic Ocean and in the Caribbean Sea, according to the USGS website.
In the rural area where the quake occurred, the North American plate is moving westward along a fault that Hutton said is a few miles long at most.
East Coast quakes tend to be felt over much larger areas than their West Coast counterparts, making them potentially damaging to a wider region, according to Thomas Hillman Jordan, director of the Southern California Earthquake Center at the University of Southern California in Los Angeles.
While the chances of yesterday’s earthquake or an aftershock causing significant damage are small, it’s a wakeup call, Jordan said in a telephone interview.
“It’s a good reminder that even a moderate-size earthquake occurring in a built-up region could be quite disastrous,” he said.
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