You may have felt the ground shaking in Philadelphia on Friday — the result of a 4.8 magnitude earthquake that hit Whitehouse Station, New Jersey and reverberated across much of the mid-Atlantic. It was the strongest recorded earthquake to hit the region in over a decade, per NBC News.
Earthquakes aren’t usually a top-of-mind phenomenon in Philly … but they’re not unheard of, either. Keep scrolling for some interesting things to know about earthquakes in our region, from 19th-century happenings to last Friday’s event ⬇️
East Coast vs. West Coast Quakes
Big earthquakes are a lot less common in our region than they are on the other side of the country. The Associated Press reported that the East Coast has had less than two dozen earthquakes above magnitude 4.5 since 1950, while the West Coast has had 1,000+ over that time span.
But when East Coast earthquakes do happen, they’re more likely to be felt across a much wider swath of land. That’s because the earth’s crust is older and less broken up here than it is on the West Coast, a United States Geological Survey seismologist told The Washington Post.
Friday’s Earthquake Spawned Tons of Aftershocks
New Jersey experienced at least 39 aftershocks — i.e., smaller earthquakes following a larger event — of varying sizes between Friday and Sunday, according to NJ.com. Eighteen of them happened within the first three hours of the big shake, The Philadelphia Inquirer reported. Experts with the USGS say even more are possible in the week ahead.
Philly Was Once Rattled by a Missouri Earthquake
In 1811 and 1812, a series of three huge earthquakes hit New Madrid, Missouri. The impact was felt so widely that even Northeasterners reported feeling the ground shake.
“I was much surprised with an uncommon noise, like that of a heavy [stagecoach], going with great velocity over a stone pavement,” a Germantown resident wrote to Poulson’s American Daily Advertiser in February 1812. “The impression made on my mind was of an awful kind.”
🌎 For more earthquake facts, check out today’s episode of the City Cast Philly podcast to hear our executive producer Laura Benshoff break them down.
