Quake: Not big but big for Virginia

STAFFORD — David Kitchen, a University of Richmond geologist, said that Tuesday afternoon's earthquake that struck near Mineral, was "still not a big earthquake" but "for Virginia, it was very big," said another state geologist.  
Perhaps the most important message from the 5.8-magnitude quake, Kitchen said, is a reminder that central Virginia has lots of earthquakes. We just don't feel most of them.
"People think of the West Coast as being the place where earthquakes take place, but the East Coast is seismologically active," Kitchen said.
Virginia's previous earthquake champ, an estimated 5.8-magnitude quake in Giles County, occurred in 1897 and was felt in 12 states. It broke off stone chimneys and muddied springs.
Instruments were not sophisticated then, and that quake might even have been a 5.6 or 5.7, experts say. So Tuesday's quake could be Virginia's all-time record.
By comparison, the quake that struck Haiti in January 2010, killing more than 300,000 people, was a magnitude 7.0.
Each point in the magnitude scale represents a 30-fold increase in energy. So the Haiti quake was more than 30 times more powerful than Tuesday's quake. 
The magnitude 5.8 earthquake Tuesday rattled residents up and down the East Coast. In Northern and Central Virginia, residents reported some broken glass and no cell phone service in the aftermath.
A few injuries rose to the surface in the aftermath of the quake, but no major injuries were reported in the immediate area. Stafford County Sheriff’s Office Public Information Officer Bill Kennedy said following the incident that phone lines in the area were busy, but 911 was operational. Many calls were coming into the sheriff’s office, he said, some with questions on whether the incident was an explosion. The sheriff’s office quickly went to work checking on damages in the county, he said.
County Public Information Manager Cathy Riddle said that damage assessment was under way right after the earthquake occurred, with no major damage at critical care facilities to include the Stafford Hospital Center. There were no problems with the area dams, she said.
The earthquake probably occurred because underground rocks, subjected to weight from the earth above and to horizontal pressures remaining from the movement of underground plates millions of years ago, moved along a fault, said Chester "Skip" Watts, a Radford University engineering geologist.
People reported feeling the quake from New England to Georgia. "For Virginia, it was very big," Watts said. 
Virginia has several earthquakes each year, but most are quite small.
In California, some faults run along the Earth's surface. Scientists can measure movements along the faults, getting a rough idea of the probability of an earthquake, experts say.
In Virginia, experts can't predict earthquakes. But they know more are on the way.
Kipp Hanley of the News & Messenger contributed to this report.