Earthquake risk in New York substantially greater than formerly believedAugust 22nd, 2008 - 4:08 pm ICT by ANI
Washington, August 22 (ANI): A study by a group of prominent seismologists has suggested that a pattern of subtle but active faults makes the risk of earthquakes to the New York City area substantially greater than formerly believed.
Many faults and a few mostly modest quakes have long been known around New York City, but the research casts them in a new light.
According to scientists, the insight comes from sophisticated analysis of past quakes, plus 34 years of new data on tremors, most of them perceptible only by modern seismic instruments.
The evidence charts unseen but potentially powerful structures whose layout and dynamics are only now coming clearer.
All are based at Columbia Universitys Lamont-Doherty Earth Observatory, which runs the network of seismometers that monitors most of the northeastern US.
According to lead author Lynn R. Sykes, the data shows that large quakes are infrequent around New York compared to more active areas like California and Japan, but that the risk is high, because of the overwhelming concentration of people and infrastructure.
The research raises the perception both of how common these events are, and, specifically, where they may occur, said Sykes. Its an extremely populated area with very large assets, he added.
The researchers compiled a catalog of all 383 known earthquakes from 1677 to 2007 in a 15,000-square-mile area around New York City.
Coauthor John Armbruster estimated sizes and locations of dozens of events before 1930 by combing newspaper accounts and other records.
The researchers said that magnitude 5 quakesstrong enough to cause damage - occurred in 1737, 1783 and 1884.
There was little settlement around to be hurt by the first two quakes, whose locations are vague due to a lack of good accounts; but the last, thought to be centered under the seabed somewhere between Brooklyn and Sandy Hook, toppled chimneys across the city and New Jersey, and panicked bathers at Coney Island.
Based on this, the researchers said that such quakes should be routinely expected, on average, about every 100 years.
Today, with so many more buildings and people, a magnitude 5 centered below the city would be extremely attention-getting, said Armbruster. Wed see billions in damage, with some brick buildings falling. People would probably be killed, he added.
Among other things, the researchers said that the controversial Indian Point nuclear power plants, 24 miles north of the city, sit astride the previously unidentified intersection of two active seismic zones. (ANI)