A small earthquake shook Maryland's Howard County early Wednesday, according to the U.S. Geological Survey.
The quake with a preliminary magnitude of 2.1 occurred at about 2:10 a.m. It was centered in Clarksville, about 15 miles southwest of Baltimore, and was about 2.1 miles deep.
About five hours later, the agency had received more than 300 reports through its website from people who felt the temblor across the region, including 47 miles to the south in Charles County and 37 miles to the northwest in Frederick County.
An earthquake with a magnitude of 2.6 struck in the Woodlawn area, west of Baltimore on June 25 and minor aftershock with a magnitude of 1.7 was recorded two days later. Neither caused any noteworthy damage or injuries.