BAR HARBOR – Nearly a week after many local residents were awakened by a rare earthquake on the eastern side of Mount Desert Island, they experienced two relatively powerful aftershocks Thursday morning.

The tremors were felt around 10 a.m., according to the Bar Harbor Police Department.

“It sounded like loud thunder,” Dispatcher Sharon Worcester said of Thursday’s quake. “I could feel it.”

According to Dina Smith, associate director of operations for Boston College’s Weston Observatory, there were two aftershocks Thursday morning, one around 9:50 and another about 5 minutes later. Weston Observatory monitors seismic activity in New England on behalf of U.S. Geological Survey, she said.

The estimated epicenter for both aftershocks was determined to be in Frenchman Bay, about four miles north of Bar Harbor’s village, according to Smith. The registered magnitudes for Thursday’s aftershocks were 1.8 and 2.5, she said, well below the 5-magnitude level for damage-causing quakes.

Smith said having six confirmed foreshocks and aftershocks stemming from the 3.4-magnitude earthquake on Sept. 22 is rare. The 15 other unconfirmed related tremors that have been reported over the past week and the magnitude of Thursday’s larger aftershock also is uncommon.

“The number of events is unusual,” Smith said. “That’s pretty big for an aftershock a week later.”

As of Thursday afternoon, USGS had received through its official Web site roughly 110 reports from the public about seismic activity in the area over the past week. Thirty-five earthquakes have been reported in Maine since 1997, while the most powerful earthquake ever recorded in the state was a 5.1-magnitude temblor in Calais and Eastport on March 21, 1904, according to USGS.

Smith said there could be more seismic activity in store for MDI in the near future but that there is no way of knowing for sure.

Since last week, scientists have revised the estimated epicenter location of the Sept. 22 earthquake from Kebo Mountain to the eastern face of Champlain Mountain. Both sites are roughly within a mile of Jackson Laboratory, a world-renowned facility that specializes in mouse genetics and in breeding mice for scientific purposes.

Joyce Peterson, spokeswoman for the lab, said Thursday that the tremors have had no known lasting effects on the institution. No damage has been found at any of the buildings or structures on the lab’s Route 3 campus, she said, and the mice have shown no ill effects from the rumblings.

“By the time you thought about it, it was gone,” Peterson said of the thump she felt Thursday.

She said the lab has had bedrock blasted out of the ground for recent capital projects and that the staff has been careful to minimize the effects the blasting might have on the mice. If the quake has had any lasting effect on the reproductive habits of the mice, which Peterson said is unlikely, it would take several weeks before scientists could confirm it.

“I would be very doubtful about that,” she said.

David Manski, Acadia National Park’s head of resource management, said Thursday that the park has been relying on information from Weston Observatory and from USGS because it has no geologist or seismologist on staff. He said park officials have gone out to see if the tremors have had any effects on park land, which surrounds both the initial and revised estimated epicenters of last week’s earthquake.

“We’ve gone to both epicenters and didn’t really see anything,” Manski said.