Historic Earthquakes

Cape Ann, Massachusetts
1755 11 18 09:11:35 UTC
Intensity VIII

Largest Earthquake in Massachusetts

Cape Ann Earthquake
Image courtesy of National Information Service for Earthquake Engineering, University of California, Berkeley.

Woodcut illustration showing contemporary account of damage to Boston, Massachusetts, during the Cape Ann earthquake of November 18, 1755. Shaking was strongest northeast of Boston. The earthquake caused considerable damage in Boston, knocking down or damaging as many as 1,600 chimneys and collapsing brick walls of several buildings.

This earthquake caused the heaviest damage in the region around Cape Ann and Boston. At Boston, much of the damage was confined to an area of infilled land near the wharfs. There, about 100 chimneys were leveled with the roofs of houses, and many others (1,200 to 1,500) were shattered and partly thrown down. Some chimneys, which were broken off below their tops, tilted dangerously 3 or 4 centimeters; others were twisted or partly turned. The gable ends of several brick buildings (12 to 15) were thrown down, and the roofs of some houses were damaged by the fall of chimneys. Stone fences were thrown down throughout the countryside, particularly on a line extending from Boston to Montreal. New springs formed, and old springs dried up. At Scituate (on the coast southeast of Boston), Pembroke (about 15 kilometers southwest of Scituate), and Lancaster (about 40 kilometers west of Boston), cracks opened in the earth. Water and fine sand issued from some of the ground cracks at Pembroke.

This earthquake was reported from Halifax, Nova Scotia, south to the Chesapeake Bay in Maryland and from Lake George, New York, east to a ship 320 kilometers east of Cape Ann. The shock was felt so strongly on the ship that those onboard believed the ship had run aground. Several aftershocks occurred.

Abridged from Seismicity of the United States, 1568-1989 (Revised), by Carl W. Stover and Jerry L. Coffman, U.S. Geological Survey Professional Paper 1527, United States Government Printing Office, Washington: 1993.