In recent weeks, Virginia has been rattled with more earthquakes than usual, leading some experts to wonder whether a larger quake might be coming.
Six quakes have been detected in the western portion of the state since mid-June, according to the United States Geological Survey, with headquarters in Fairfax County.
At least three of the earthquakes were felt by people.
Typically, only two or three quakes per year are felt by residents across Virginia.
“It’s a little bit of a burst of activity here,” said Martin Chapman, a professor of geophysics at Virginia Tech. “When you see a series of these things in a smaller area, you have to take into account the fact that they may be foreshocks of a bigger earthquake.”
For scale, a magnitude 5.3 is considered to be a moderate earthquake, and a magnitude 6.3 is a strong one. All the recent Virginia quakes have been smaller, around the magnitude 2.5 level.
“We take a close look at it and we monitor our instruments a little bit closer to make sure that we’re not missing any more little earthquakes, because if you see a continuous sequence that’s something that you have to pay attention to,” Chapman said.
Although, not every large earthquake comes after “foreshocks.”
The quake in Mineral, Virginia, that shook the D.C. area back in 2011 was a magnitude 5.8 and it came out of the blue.
“We didn’t see any foreshocks for that earthquake,” Chapman said. “You can’t always predict what earthquakes are going to do.”
The 2011 quake was probably the most widely-felt earthquake in North American history, owing to the Eastern Seaboard’s population density, according to the Reston-based United States Geological Survey
It left behind between $200 and $300 million in property damage.
Structures that were dinged up included the Washington Monument, which had masonry on all four of its sides damaged. The Washington National Cathedral suffered around $34 million in damages.
“I just remind everybody in Virginia that we do have earthquakes and occasionally they’re damaging,” Chapman said. “Just be aware of the fact that we can have those things.”
