John E. Ebel, Ph.D., Professor of Geophysics, Boston College
Director, Weston Observatory of Boston College
Jeremiah Newland's Verses Occasioned by the Earthquakes in the Month of November, 1755 reminded readers of the hand of God at work in the natural environment. His use of the word "earthquakes" in the title was no mistake--just 17 days prior to the Cape Ann earthquake, a massive earthquake struck Lisbon, Portugal, destroying much of the city and causing a huge loss of life. Newland's verse cautioned New Englanders to change their ways lest God "strong enough to sink the whole Creation," punish New England as he had Lisbon.
At about 4:30 in the morning on 18 November 1755, a strong earthquake rocked the New England area. Observers reported damage to chimneys, brick buildings, and stone walls in coastal communities from Portland, Maine to south of Boston, Massachusetts. Chimneys were also damaged as far away as Springfield, Massachusetts, and New Haven, Connecticut. The earthquake was felt at Halifax, Nova Scotia, to the northeast, Lake Champlain to the northwest, and Winyah, South Carolina to the southwest. The crew of ship in deep water about 70 leagues east of Boston thought it had run aground and only realized it had felt an earthquake when it arrived at Boston later that same day.
The 1755 earthquake rocked Boston, with the shaking lasting more than a minute. According to contemporary reports, as many as 1500 chimneys were shattered or thrown down in part, the gable ends of about 15 brick buildings were broken out, and some church steeples ended up tilted due to the shaking. Falling chimney bricks created holes in the roofs of some homes. Some streets, particularly those on manmade ground along the water, were so covered with bricks and debris that passage by horse-drawn carriage was impossible. Many homes lost china and glassware that was thrown from shelves and shattered. A distiller's cistern full of liquor broke apart and lost its contents.
A smaller shock followed the main earthquake about an hour and a quarter later. The northeastern coast of Massachusetts experienced a number of smaller aftershocks during the next week, but only one of these was felt in Boston. In the days after the earthquake, local ministers conducted prayer services and government officials proclaimed fast days, observed by those who felt God's wrath had brought this earthquake upon Boston.
Jeremiah Newland was not the only author inspired by the earthquake of 1755. In the weeks and months following the quake, no fewer than twenty-seven sermons, poems, and accounts of other earthquakes were published in New England. With such titles as Earthquakes the Works of God and Tokens of his Just Displeasure (by Thomas Prince) and The Duty of a People, Under Dark Providences, or Symptoms of Approaching Evils, to Prepare to Meet their God (by Eliphalet Williams), there can be little doubt as to the prevailing view of the cause of the earthquake. John Winthrop (1714-1779), the Hollisian Professor of Mathematics and Philosophy at Harvard, took a more scientific approach in his lecture at the college a week after the earthquake, attributing the shaking to a violent reaction of heat and chemical vapors deep within the earth's surface, all under God's direction, of course. At the time, Winthrop's scientific explanation was countered by another that posited the use of lightning rods as a contributing factor.
From comparisons of damage reports and felt areas of the 1755 earthquake with those same observations for modern earthquakes, the magnitude of the 1755 earthquake is estimated to have been about 6.0 to 6.3, a strong earthquake according to the modern Richter Scale. The quake's epicenter is thought to have been about 25 miles east of Cape Ann in an area of the ocean where several small earthquakes have been detected during the past 30 years. A 1997 study found that if the Cape Ann earthquake were to recur today, the City of Boston could sustain billions of dollars of earthquake damage, with many thousands injured or killed. Since so much of the city is built on artificially created landfill, Boston is particularly vulnerable to the effects of a strong earthquake.