1755 Cape Ann earthquake

The earthquake took place on November 18, 1755, at approximately 4:30 AM local time. Future President of the United States John Adams, then staying at his father's house in Braintree, Massachusetts, was awakened by the quake, which impressed him so much that he began a diary that night. He wrote that the quake "continued near four minutes" and that "[t]he house seemed to rock and reel and crack as if it would fall in ruins about us." Its epicenter is believed to have been offshore, approximately east of Cape Ann. The quake was felt as far north as Halifax, Nova Scotia, south to the Chesapeake Bay and South Carolina, and from Lake George and Lake Champlain in the northwest to a ship off the east coast. The region experienced several aftershocks, the first of which was a little more than an hour after the quake. Most of these aftershocks could not be felt in Boston, affecting only the northeastern coast of the colony. Scientists are unclear on the causes of this and other quakes in the northeastern United States. There are a number of old faults in the region, but none of them is known still to be active. Damage Boston and Cape Ann were the most heavily damaged. In Boston, damage was concentrated in areas of infill near the harbor; infill is less sturdy in earthquakes than solid land. From 1,300 to 1,600 chimneys in the city were damaged in some way, the gable ends of some houses collapsed, and a number of roofs were damaged by falling chimneys. ==Legacy==

(foreground) could suffer serious damage in a quake like 1755 Cape Ann earthquake. |alt=A cityscape including a number of skyscrapers, with a river running through the middle Many Massachusetts residents of the time perceived the quake as punishment from God for immoral behavior. In the days after the earthquake, special prayer services were held and civic authorities declared fast days. A number of sermons and other writings were published as a consequence, including Jeremiah Newland's Verses Occasioned by the Earthquakes in the Month of November 1755 and Thomas Prince's Earthquakes the Works of God and Tokens of his Just Displeasure. Well before 1755, the new rational materialist ideas promulgated by Enlightenment scientists had begun to heavily influence the better-educated citizens of colonial America; therefore not all explanations of the event were theological. John Winthrop, a Harvard professor, proposed an alternate explanation having to do with heat and chemical vapors inside the surface of the earth. John Adams, in comments in the margins of Winthrop's Lecture on Earthquakes wrote: Many of the buildings in modern Boston and its surroundings are built on infill, especially in the Back Bay area, which may be prone to greater shaking and to compaction of the sand and gravel used as fill. Many older buildings in the Boston area are masonry, and may collapse completely during a major earthquake. A 1990 study by the Massachusetts Emergency Management Agency estimated potential financial losses at between $4 billion and $5 billion, and potential loss of life in the hundreds. As a consequence, the state has updated building codes and zoning laws to require that new construction and additions in vulnerable areas be built to resist earthquakes. ==See also==