|East Coast quake a 'teachable moment'|
|Posted 2/22/2012 7:14 PM ET|
The magnitude-5.8 quake, centered in the tiny town of Mineral, Va., demonstrated that earthquakes aren't just a West Coast threat. Big quakes had hit the East Coast before but not recently nor with the frequency or ferocity of those in California.
But the Aug. 23 quake was felt by more people than any other in American history, said Marcia McNutt, director of the U.S. Geological Survey (USGS). Her agency estimates that one-third of the U.S. population — in 3,400 ZIP codes from Georgia to New York— felt the quake.PHOTOS: Earthquake rocks East Coast STORY: East shook up after quake STORY: Town at epicenter assesses damage
The Virginia quake caused no deaths but left hundreds of millions of dollars in damage. Washington, D.C., 85 miles from the epicenter, took major hits in two of its most prominent landmarks — the Washington Monument and the Washington National Cathedral, which combined could cost $40 million to repair. The monument is likely to remain closed for up to a year for repairs.
"We were lucky that earthquake struck far from very populated areas," McNutt said Wednesday, also the one-year anniversary of a quake that killed 185 people and devastated the city of Christchurch, New Zealand.
Geologists in McNutt's agency and at universities descended on the East Coast earthquake zone last August to measure aftershocks. Employing everything from airplanes shooting lasers to geologists digging holes, they are mapping a previously unknown fault line beneath the Earth's crust. The agency's data show the fault line running from central Virginia generally toward the northeast and southwest. "It is now possible to say, 'Eureka, we have found the perpetrator,' " McNutt said.
Geologists have discovered that the northeasterly direction of the shock waves and the ground in the Washington, D.C., region — sediment atop swamps and riverbeds — contributed to damage far from the epicenter.
Rob Williams, a USGS geophysicist, said engineers may see the Virginia quake "as a wake-up call for all the beautiful buildings that were built 200 years ago in the East without concern for seismic shaking."
James Cagley, chairman of the Maryland-based Cagley & Associates structural engineering firm, said the quake did not elevate his concern about earthquake threats in the eastern U.S., and he said buildings constructed since the 1990s have been made more earthquake-resistant.
But some analysts say the Aug. 23 shake will cause designers and building code officials to pay more attention to eastern quake threats.
Schools were among the most heavily damaged buildings in the Virginia-centered quake, said Steven McCabe, deputy director of the Commerce Department's National Earthquake Hazards Reduction Program. Damage to schools in California in the 1930s prompted more stringent earthquake-protection codes in that state, he said.
Russell Green, a Virginia Tech civil engineering professor, predicted that the quake will cause engineers to design buildings in the East to absorb more ground motion than previously anticipated. Green and others at Virginia Tech are finishing a national study of the East Coast quake.
James Martin, an environmental engineering professor who is directing the Virginia Tech study, said the quake was a "teachable moment" for scientists and the public.
Among his study's preliminary findings: "Areas such as Washington, D.C., are unprepared to deal with even a moderate earthquake, particularly with respect to communications, evacuation and transportation."
The study's draft recommends teaching "earthquake basics" to East Coast schoolchildren.
McNutt said her agency wants to expand the annual "Great Central U.S. Shakeout" to the East Coast. The Shakeout is an annual earthquake drill designed to prepare people in the central USA. Last month, an estimated 2.4 million people in nine states stretching from Illinois to Alabama participated. It came on the 200th anniversary of a Feb. 7, 1812, Missouri quake that was so intense it rang East Coast church bells.
Virginia's annual emergency management symposium next month will focus heavily on earthquake preparedness. Among the speakers will be Rob Dudgeon, San Francisco's deputy director of emergency management.
He will stress the difference between hurricanes, which come after days of warnings and often require mass evacuations, and earthquakes. It is often better for people to stay put after a quake, Dudgeon said.
People in cities after the Aug. 23 quake often did the opposite, evacuating buildings and driving home rather than seeking structurally safe locations indoors and leaving the roads to emergency response vehicles.
"Earthquakes are not fire drills," McNutt said. "What you don't want to do when facades are falling off buildings is file out of the buildings." That's the kind of information that East Coast residents need to hear, said Ed McDonough of the Maryland Emergency Management Agency, which is planning its first earthquake response drill in April.
|Posted 2/22/2012 7:14 PM ET|