New York earthquakes are rare, felt across broader area: Times when US cities felt 'strong' tremors

A rare earthquake of 4.8 hit the densely populated New York City metropolitan area on Friday morning, the US Geological Survey (USGS) said. "This is one of the largest earthquakes on the East Coast in the last century," New York Governor Kathy Hochul was quoted by Reuters as saying.

The earthquake centred near Whitehouse Station, was reportedly the third largest in the last 50 years and the 10th-strongest of all time in the Northeast. According to the data cited by CNN, the largest earthquake of 5.3 magnitude quake took place in Au Sable Forks, New York, in 2002. The second largest tremor of magnitude 5.1 happened in Newcomb, New York on October 7, 1983.

Meanwhile, the Associated Press (AP) cited the USGS as saying that earthquakes with magnitudes near or above 5 struck near New York City in 1737, 1783 and 1884.

Friday's earthquake also stirred memories of the August 23, 2011, that had jolted tens of millions of people from Georgia to Canada. With an epicentre in Virginia, it had left cracks in the Washington Monument and rattled New Yorkers.

A 3.8 earthquake centered east of Buffalo in the suburb of West Seneca (part of western New York) in February 2023 was said to be the region's strongest quake in at least 40 years.

Besides, the 1989 earthquake, that disrupted baseball's World Series and rocked San Francisco, was measured at a 6.9 magnitude, which would have made it more than 1,000 times more powerful than Friday's quake, Reuters reported.

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Why earthquakes are less common in east US?

The tremors, that hit near New Jersey, on Friday were reportedly felt widely from Washington, DC to New York City to New England. The region is unaccustomed to earthquakes. There have only been 24 earthquakes of 2.5 magnitude or greater in New Jersey since 1700, CNN reported.

 “The quake's epicenter was in Tewksbury in central New Jersey, about 40 miles (64 kilometers) west of New York City. It occurred just after 10:20 a.m. ET (1420 GMT) at a depth of 4.7 kilometers (2.9 miles),” the USGS said.

Earthquakes are less common on the eastern than western edges of the US because the East Coast does not lie on a boundary of tectonic plates. The biggest Eastern quakes usually occur along the mid-Atlantic Ridge, which extends through Iceland and the Atlantic Ocean, AP reported.

The USGS said earthquakes can occur in any location at any time. But history shows they occur in the same general patterns over time, principally in three large zones of the earth.

Moreover, earthquakes in the eastern US are felt across a far broader area because the bedrock is much older and harder, transferring seismic energy more easily, according to the USGS. The rocks in the western US are younger and contain more faults that absorb earthquake energy.