There are several fault lines in the metro area, including one along Manhattan’s 125th St. – which may have generated two small tremors in 1981 and may have been the source of the major 1737 earthquake, says Armbruster. There’s another fault line on Dyckman St. and one in Dobbs Ferry in nearby Westchester County.
“The problem here comes from many subtle faults,” explained Skyes after the study was published. “We now see there is earthquake activity on them. Each one is small, but when you add them up, they are probably more dangerous than we thought.”
“While uncommon, the earthquake hazard of the New York City metropolitan area has been assessed as moderate,” the New York City Area Consortium for Earthquake Loss Mitigation writes on its website. “Considering population density and the condition of the region’s infrastructure and building stock, it is clear that even a moderate earthquake would have considerable consequences in terms of public safety and economic impact.”
Armbruster says a 5.0-magnitude earthquake today likely would result in casualties and hundreds of millions of dollars in damage. “I would expect some people to be killed,” he notes. “Enough chimneys, facades on buildings would fall and someone would be underneath.”
The scope and scale of damage would multiply exponentially with each additional tick on the Richter scale.
“Will there be one in my lifetime or your lifetime? I don’t know. But this is the longest period we’ve gone without one.”