A small earthquake was reported early Saturday in Maryland, a state in which quakes strong enough to feel are relatively rare.

The 2.2-magnitude quake about 5:50 a.m. was centered near the boundary between Frederick and Carroll counties, about 40 miles north of Washington, according to the U.S. Geological Survey.

There were no indications of damage or injury, and the quake was scarcely felt.

State Police in Frederick County said no reports had been received, and Thomas Rio, Carroll’s public works director, said he had received no word of any problems.

“If it had any effect at all to county buildings or roads,” he said, “I would have been notified.”

“It is rare for Maryland to have earthquakes large enough to be felt; however, they do occur in our region and our state,” Rich Ortt, an earthquake specialist with the Maryland Geological Survey, said by e-mail.

Most reports of people feeling the quake apparently came from south of Westminster, Md., and other parts of Carroll County, Ortt said.

No effects were reported “above pictures shaking on the wall,” he said.

The quake, feeble as it may have seemed, helped to demonstrate that even in a state such as Maryland, where earthquake risk is low, conditions underground are not totally placid and serene.

Saturday’s incident was centered roughly 120 miles northeast of the site of last year’s history-making quake in Virginia. No indication of a link between them could be learned immediately.

The USGS said that more than 450 aftershocks have been recorded after last year’s 5.8-magnitude quake. They appeared to be centered much closer to the quake site.

By Saturday night, the USGS had received nine responses to the Maryland quake on its “did you feel it” site. They came from spots near the quake’s center.

By contrast, as of last month, about 148,000 people had reported feeling the Aug. 23, 2011, quake.

The last widely reported earthquake in Maryland was recorded a little more than two years ago, on July 16, 2010, and was initially reported to have had a magnitude of 3.6.

That quake was centered in the Germantown-Gaithersburg area, near Interstate 270 and Route 119. At the time it was said to be the largest in more than 30 years to occur within about 45 miles of Germantown.

The largest in that zone before the 2010 quake was reported as having a 2.7-magnitude and occurred in 1993, a USGS geophysicist said at the time. In addition, there had been one in 1990 with a 2.7-magnitude and three gauged at 2.5 in 1997, 1993 and 1974.

The 2010 quake, which raised the Washington area’s earthquake consciousness, was reported to the USGS by more than 6,700 people in the first two hours after it occurred.

Saturday’s quake, according to the survey, was about three miles north-northeast of Linganore, Md., and about halfway between Westminster, Md., in Carroll, and the city of Frederick, in Frederick County. Initially, it was described as having a magnitude of 2.1, but later descriptions put it at 2.2.