It might not seem like an obvious location, but New York may be overdue an earthquake that could cause substantial damage.
The claim was made by journalist Kathryn Miles in her new book, Quakeland: On the Road to America's Next Devastating Earthquake. The region apparently experiences a major earthquake every hundred years, the last being back in 1884.
New York has a number of geological faults running northeast and northwest. They create what Miles calls a “brittle grid” under Manhattan, which is a bit of a ticking time bomb for an earthquake. The rock under New York is very hard, so an earthquake could cause considerably more damage than one on the West Coast.
Geophysicist Charles Merguerian studies the faults, by walking surface fault lines, and going underground. He says he’s walked the entire island of Manhattan, including most of its tunnels, helping to reveal the number of faults lying underground.
“To do his work, then, he’s primarily looking for what geologists call “offsets” – places where the types of rock don’t line up with one another,” Miles wrote in an excerpt run by The Daily Beast. “That kind of irregularity shows signs of movement over time – clear evidence of a fault.”
It’s thought the faults formed millions of years ago when the East Coast played host to a violent subduction zone (where tectonic plates collide). The Mid-Atlantic has “folded into itself again and again”, leaving not only mountains but solid and brittle rock that could cause an earthquake.
New York has not been devoid of earthquakes. One relatively small one, 2.6 in magnitude (M), struck back in October, 2001. A 5.0M earthquake is thought to hit every hundred years, so the city is long overdue. There’s also another fault, called Ramapo, close to the city that could cause an earthquake up to 7.0M.
The East Coast of the US is certainly not a region that gets mentioned much when talking about earthquakes. The West Coast, and the threat of a “really big one”, garner a lot more attention. But maybe we should really be taking a look at what’s happening under New York.