Yes, the Earth did shake in Philadelphia Thursday afternoon.

According to the United States Geological Survey, a 4.1 magnitude earthquake struck about eight miles off the coast of Dover at 4:47 p.m, prompting people throughout the city to wonder what the hell just happened. (Ed. Note: Our original story had listed the quake as a 4.4, but it was subsequently downgraded to a 4.1.)

Thursday’s quake was felt as far north as NYC and as far south as the D.C. area.

A quake of this magnitude earthquake is considered minor and usually causes minimal damage, if any. Though we don’t hear often about earthquakes in the Northeast, they do occur pretty frequently. There have been 76 in the Northeastern U.S. and Southeastern Canada since June 1, though most of them were under a magnitude of 2, so were basically unnoticeable by humans.

The last time Philadelphia felt anything similar to this was 2011, when a 5.9 earthquake hit Virginia, causing broken windows and other minor destruction.

The Geological Survey’s crowd-sourced tracking of the quake shows residents of Washington DC, New York and Baltimore felt the earthquake, too.

And did you hear about the earthquake over the internet before you actually felt the earthquake? There’s a reason for that. Tweets move faster than seismic waves.

Mark Dent is a reporter/curator at BillyPenn. He previously worked for the Pittsburgh Post-Gazette, where he covered the Jerry Sandusky scandal, Penn State football and the Penn State administration. His...