1963Two earthquakes at sea were felt on Cape Ann two weeks apart.Events & Anniversaries, Natural Disasters

The first slight earthquake was felt throughout eastern Massachusetts starting around 11:30 am on the morning of October 16, 1963. A geologist at the Weston Observatory of Boston College reported that the center of the earthquakes was off the coast in the Atlantic Ocean.
The second occurred two weeks after the first on October 31, 1963. The source was only 10 miles at sea between Boston and Gloucester.
Gloucester Daily Times. "New quake jolts Cape Ann; it's only 10 miles away." October 31, 1963.