A Magnitude-4.1 Earthquake Just Hit Delaware

Delaware Earthquake
The epicenter of a magnitude 4.1 earthquake hit near Dover, Delaware, today (Nov. 30). (Image credit: U.S. Geological Survey)

This story was updated Nov. 30 at 11:18 p.m. EST. 

A magnitude-4.1 earthquake just hit near Dover, Delaware, surprising people in the First State, a place unaccustomed to tremblers.

The earthquake hit 5 miles (8.1 kilometers) underground at 4:47 p.m. EST today (Nov. 30), according to the U.S. Geological Survey (USGS). The epicenter, located within the Bombay Hook National Wildlife Refuge, was 6.4 miles (10.3 km) east of Delaware's capital, Dover, which has a population of about 36,000, USGS reported.

People reported feeling the earthquake in Delaware, New Jersey, Pennsylvania, Maryland, New York, Virginia and Washington, D.C., according to the USGS "Did You Feel It?" site, where people can report where they felt the ground shake. [The 10 Biggest Earthquakes in History]

There is no tsunami warning from the earthquake, according to the National Oceanic and Atmospheric Administration. Moreover, there are no reports of injuries or damages, Gary Laing, a spokesman with the Delaware Emergency Management Agency, told Delaware Online.  

The earthquake also registered at the Lamont-Doherty Earth Observatory in New York, meteorologist Brian Lada noted on Twitter.

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Earthquakes are uncommon east of the Rocky Mountains. However, when they happen, they're often felt over a much broader area than earthquakes of similar-magnitudes on the West Coast, according to the USGS. In fact, East Coast earthquakes "can be felt over an area more than 10 times larger than a similar magnitude earthquake on the West Coast," the USGS wrote in a statement.  

A shake map for the Delaware earthquake (Image credit: U.S. Geological Survey)

It's not yet clear what caused today's earthquake, but most earthquakes on the East Coast occur at faults within bedrock, the USGS reported.

The last big quake to hit the East Coast was the 5.8-magnitude earthquake near Mineral, Virginia, that surprised tens of millions of people on Aug. 23, 2011. That earthquake was felt from Maine to Georgia, and as far west as Chicago, according to the USGS.

The 2011 earthquake was caused by geologic structures within the Appalachian Mountains, whose curves reflect the twisted remains of ancient continental collisions, Live Science previously reported.

Editor's Note: This story was updated to reflect that the earthquake was a 4.1-magnitude earthquake, not a 4.4-magnitude earthquake as USGS previously reported. 

Original article on Live Science.

Laura Geggel

Laura is the archaeology and Life's Little Mysteries editor at Live Science. She also reports on general science, including paleontology. Her work has appeared in The New York Times, Scholastic, Popular Science and Spectrum, a site on autism research. She has won multiple awards from the Society of Professional Journalists and the Washington Newspaper Publishers Association for her reporting at a weekly newspaper near Seattle. Laura holds a bachelor's degree in English literature and psychology from Washington University in St. Louis and a master's degree in science writing from NYU.