The Louisa County High School in Mineral, Va., was damaged beyond repair during the magnitude 5.8 earthquake in August 2011 that was centered beneath the town, about 50 miles northwest of Richmond.(Photo: Steve Helber, AP)
The August 2011 earthquake that jolted the East Coast may have been
felt by more Americans than any quake in U.S. history as it sent
damaging tremors four times farther and over an area 20 times larger
than previously documented, the U.S. Geological Survey announced Tuesday.
The magnitude 5.8 earthquake,
centered in Mineral, Va., northwest of Richmond, triggered landslides
150 miles away -- more than twice as far as previous studies of
magnitude 5.8 quakes worldwide. It was the strongest in the eastern USA since 1897.
landslide distances from last year's Virginia earthquake are remarkable
compared to historical landslides across the world and represent the
largest distance limit ever recorded," said Edwin Harp, a USGS scientist
and co-author of the study presented Tuesday at the Geological Society of America conference. The findings will be published in the December issue of the Bulletin of the Seismological Society of America.
research bolsters previous findings that although earthquakes are less
frequent in the eastern USA, the region's geology can spread tremors,
and damage, over a wider area than in the West.
Marcia McNutt.said said "empirical data" confirms that "more than 50
million people" in the eastern states "experienced" the effects of the
powerful quake but that nearly one-third of the nation's population may
have felt it. Residents of Midwestern and Southern states reported
Equations used to predict ground shaking might need to be revised, Harp told the Associated Press. The new data are also likely to affect building codes and emergency preparedness.
Aug. 23, 2011, earthquake caused more than $200 million in damage,
including to the Washington Monument and National Cathedral.
The "big daddy" quake to hit the East occurred in 1886 beneath Charleton, S.C., the Philadelphia Inquirer notes. Its magnitude was estimated at 6.6 to 7.3.