The Northeast United States rests on many ancient fault lines. Each year, several small earthquakes occur, with the worst quake occurring in 1755. Newburyport is located 45 miles north of Boston. On December 4, 1852, a small earthquake struck Newburyport, Massachusetts. The quake was felt in Portsmouth NH to the north, and Salem to the south. Little damage was reported, but earthquakes occur infrequently and residents of the town were shocked. The December 10, 1852 Barre Patriot published an article from the Newburyport Herald about the quake:
"The heavy shock, and long and loud reverberation, resembling more the roar of a burning chimney flue than any thing else, on Saturday night, about half past 11 o'clock, was unquestionably a genuine and veritable earthquake, such as has seldom if ever occurred before in this latitude, although the valley of the Merrimac, more than any other portion of the Northern States, is famed for frequent, but not very vigorous earthquakes.
Those who have been in countries subject to powerful earthquakes, during these shocks, tell us that there could be no mistaking by one who had before heard the sound of a genuine earthquake. It seems hardly possible that so powerful a subterranean explosion could have occurred without causing a marked disruption of the earth at one or more places. We hope those persons in the neighborhood of ravines, in the vicinity of the river, or of ponds and of swamps as well as all other places where there may have occurred any change in the earth, will make investigations before the fall of snow shall cover up the traces.
The shock was felt at Salem on one side, and Portsmouth on the other, but evidently by the descriptions, much less powerfully than here. It was felt at West Newbury, at Amesbury, at East Haverhill and Haverhill Village, perhaps as heavily as here.
Here, though the shock was grand and sublime it did not meet the idea we have formed of an earthquake, because the shaking of the earth, though very considerable, was not such as to correspond with the loudness and long continuance of the noise, both of the burst and the roar; and seemed to resemble more the jar caused by a loud peal of thunder directly overhead. We happened to be standing at the moment beside a stove, with a hand up on the mantle piece on the chimney. The first sensation was almost stunning, and we thought of an explosion in the chimney above, throwing out the stove, and the bricks in the room overhead. The stove resting with its hind legs on the hearth, was powerfully shaken and rattled to a greater degree than it is now possible to shake them by the hands.
After the shock had passed, and we had looked at the clock to note the time, the roar continued for a full minute, and although before convinced that it was an explosion or an earthquake, we again thought it was the roar of fire in the chimney flue above, and before the sound died away, started to investigate. Estimating that half a minute had elapsed before we realized the occurrence sufficiently to look at the clock, which we think cannot be far from the fact, it was within a few seconds or two minutes from the first shock before we lost the last sound of the reverberation.
The night at the time was very calm and still, the moon shining brightly with a light air coming a little from the west of N.W., and the sound to those out of doors, in the Market square seemed evidently to come from the North, and passed off to the South. The tide was very nearly full at the time. The wind had been quite fresh from the west until about 10 o'clock, when it lulled into a calm. The ground was very wet, there having been an inch and six tenths of rain within the preceding 24 hours.
These earthquakes in this vicinity, and there have been several of them within our remembrances, well marked and defined, besides others of force so slight, as hardly to be noticed, have occurred almost uniformly after a heavy rain or a high stage of the river, and more often than at any other time just after a winter freshet. It may be that there is some great cavern between the head of tide water on the Merrimack and the ocean, which fills with subterranean gases and into which water is occasionally forced, producing the concussion.
We intended to say yesterday, that the shock of Saturday night was the greatest of all which have occurred in this vicinity in modern times. Coffin's history of Newbury gives notices of several in the early settlement of the country, which must have been more severe, as they threw over chimneys and stone walls in some places. Probably, however, the chimneys were not so well built in those days."
A complete guess would be that the earthquake was a 4.5 on the Richter Scale.