GOLDEN, Colo.—The earthquake that struck Virginia on Tuesday hit an area that historically is not seismically active—and there’s no connection with another rare quake that struck Colorado, a U.S. Geological Survey scientist said.
USGS geophysicist Daniel McNamara said Tuesday’s magnitude-5.9 quake that rattled much of the East Coast cannot be traced to a specific fault.
The same applies to a magnitude-5.3 quake that struck southern Colorado late Monday, McNamara said. That area, too, has seen little seismic activity on such a large scale.
McNamara stressed there was no connection between the two quakes. Neither was the direct product of tectonic plate movement, he said.
Virginia, like southern Colorado, sits atop fault lines “that may be hundreds of millions of years old that can reactivate when stresses build up,” McNamara said. “These are old faults from the distant geological past.”
“Both events are seismically large for these areas,” he said. “It is a bizarre day.”
