Published 30th April 2018
RISK: A seismic hazard map of New York produced by USGS
“New York is susceptible to seismic shaking from earthquakes at much greater distances” Dr Simon Day, natural disaster researcher
This is because the bedrock underneath parts of NYC, including Long Island and Staten Island, cannot effectively absorb the seismic waves produced by earthquakes.
“An important feature of the central and eastern United States is, because the crust there is old and cold, and contains few recent fractures that can absorb seismic waves, the rate of seismic reduction is low.
Central regions of NYC, including Manhattan, are built upon solid granite bedrock; therefore the amplification of seismic waves that can shake buildings is low.
But more peripheral areas, such as Staten Island and Long Island, are formed by weak sediments, meaning seismic hazard in these areas is “very likely to be higher”, Dr Day said.
“Thus, like other cities in the eastern US, New York is susceptible to seismic shaking from earthquakes at much greater distances than is the case for cities on plate boundaries such as Tokyo or San Francisco, where the crustal rocks are more fractured and absorb seismic waves more efficiently over long distances,” Dr Day said.
In the event of a large earthquake, dozens of skyscrapers, including Chrysler Building, the Woolworth Building and 40 Wall Street, could be at risk of shaking.
“The felt shaking in New York from the Virginia earthquake in 2011 is one example,” Dr Day said.
On that occasion, a magnitude 5.8 earthquake centered 340 miles south of New York sent thousands of people running out of swaying office buildings.
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