Seismometer needles quivered across South Carolina on Tuesday morning when a massive earthquake shook Pakistan — 7,676 miles away.
That’s how strong the 7.7 magnitude quake was. It serves as timely reminder as the region readies to observe the Great Southeast ShakeOut on Oct. 17.
Quakes more normally are associated with Western mountain regions, but the Southeast — and the Charleston area particularly — is also vulnerable to quakes. The temblors don’t have the frequency or the rep, but they can have the smack:
A 5.8-magnitude earthquake in rural Virginia in 2011 damaged buildings in Washington, Baltimore and as far as Philadelphia more than 200 miles away.
The devastating 1886 Charleston earthquake is thought have been a 7.3 magnitude on the Richter scale. It killed 100 people, leveled nine of every 10 brick buildings in Charleston and damaged nine of every 10 in Summerville.
The coastal area around Charleston is particularly vulnerable; three faults underground converge on each other somewhere below the Ashley River near Middleton Place, the edges of tectonic plates pressing against each other. That was ground zero for the 1886 quake.
Here are a few more things that might surprise:
The Pakistan quake shook the Lowcountry about 10 times stronger than the normal background “noise” of ground shaking from cars, machines, waves, winds or people walking. But it was not enough to feel, said Steve Jaume, College of Charleston associate director of earthquake science.
Most earthquakes of a magnitude of 6 or stronger are powerful enough to be picked up by seismometers across the globe.
A series of three minor earthquakes that shook Summerville in less than a week this month wasn’t that unusual. Small quakes tend to occur in bunches, then quiet. The quakes, each slightly stronger than a 2 magnitude, occurred Sept. 15, 19 and 20.
Summerville, in fact, pretty much shakes all the time. Highly sensitive sensors were placed in the area in 2011-2012; the sensors could pick up quakes too tiny for seismometers. They found that an average 10-12 of those quakes occur per month there.
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