May 16: The Biggest Earthquake in Connecticut History


Today in 1791, the Land of Steady Habits was shaken by the worst earthquake in Connecticut history. Two powerful tremors within minutes terrified residents and damaged homes throughout the center of the state. Reports from as far away as Boston and New York City confirmed the widespread impact of that night’s seismic activity.

While it was impossible to determine the precise epicenter of the quake, many residents claimed the tremblor emanated from the Moodus area of East Haddam, in south-central Connecticut. The land around Moodus had a long and infamous history of producing strange, unsettling seismic booms — a history that predated English settlement. Indeed, the name “Moodus” came from the Native American name Machimoodus, commonly translated as “place of noises.”

One contemporary eyewitness account described the 1791 earthquake and aftershocks as follows:

“It began  . . . with two very heavy shocks in quick succession. The first was the most powerful; the earth appeared to undergo very violent convulsions. The stone walls were shaken down, chimnies [sic] were untopped, doors which were latched were thrown open, and a fissure in the ground of several rods in extent was afterwards discovered. Thirty lighter ones succeeded in a short time, and upwards of one hundred were counted in the course of the night.

This shock was felt at a great distance. It was so severe at Killingworth [modern-day Clinton], about twenty miles distant, that a Capt. Benedict, who was walking the deck of his vessel, then lying in the harbor of that place, observed the fish to leap out of water in every direction as far as his eye could reach. The atmosphere was perfectly clear and pleasant, and the moon, which was near its full, shone remarkably bright. On the night of the 17th, six more were observed. The atmosphere was still clear and warm.”

Modern seismologists estimate that the 1791 earthquake would have registered between 4.4 and 5.0 on the Richter scale, a level right on the threshold of causing severe damage. The “Moodus Noises” and strange seismological activities continue to this day; as recently as January 2015, scientists recorded a notable “swarm” of minor earthquakes in the area. A whole lot of shakin’ goin’ on, today in Connecticut history.

Further Reading

Largest Earthquake in Connecticut,”

Justin Starr, “Earthquake Sounds: The Legends, Folklore, and ‘Noises’ of Moodus, CT,” Boston College’s Weston Observatory

History of Earthquakes in Connecticut,” (Northeast States Emergency Consortium)