A magnitude 4.1 quake struck Delaware on Thursday, in a rare seismological occurrence for the US Northeast, the US Geological Survey said.
The quake, previously reported at magnitude 5.1 and then at 4.4, was centered in the Bombay Hook National Wildlife Refuge, according to a statement from the Delaware Emergency Management Agency. It was less than 10 miles (17 km) from the city of Dover and less than a mile (0.8 km) from Donas Landing.
There were no reports of injuries or damage, officials said.
The quake was downgraded to a magnitude 4.1 after data came in from several monitoring stations, U.S. Geological Survey geophysicist Rafael Abreu said by telephone.
It was felt in Philadelphia in the neighboring state of Pennsylvania, some 53 miles (85 km) from the epicenter.
The quake was shallow, only 5 miles (8 km) deep, which would have amplified its effect, and some people reported feeling light shaking in areas around New York City and Baltimore, according to the USGS website.
Many social media users also confirmed feeling the temblor and #earthquake had quickly risen to the top of trending topics on Twitter with more than 11,000 tweets mentioning the hashtag.