4.6-magnitude earthquake centered in Maine shakes New England A 4.6-magnitude earthquake struck west of Portland, Maine, on Tuesday evening, the U.S. Geological Survey said, and the tremor reportedly was felt as far south as Boston. The USGS said the quake struck at 7:12 p.m. ET and was centered about three miles west of Hollis Center, Maine. That's about 20 miles west of Portland. It was a shallow quake at 3.1 miles deep. Reuters reported that the quake was felt in Boston, about 100 miles southwest of Portland. There were no initial reports of damage or injuries.