Historical Seismicity ofNew England

Justin Starr

Weston Observatory

Department of Earth and Environmental Sciences, Boston College

How does one determine an How does one determine an earthquake epicenter and earthquake epicenter and

magnitude, if no seismic data is magnitude, if no seismic data is recorded?recorded?

What would you do if you felt an What would you do if you felt an earthquake today?earthquake today?

…….after the shaking stops, of course.…….after the shaking stops, of course.

Correspondence and diary/journal entriesCorrespondence and diary/journal entries

The Pilgrims felt their first earthquake in 1638.

From William Bradford’s history of Plymouth:

“This year (1638) aboute ye 1. or 2. of June was a great & fearfull earthquake. . .the earth begane to shake and came at length with that violence as caused platters, dishes, & such like things as stoode upon shelves, to clatter and fall downe; yea persons were afraid of ye houses them selves. . .ye earth shooke with yt violence as (the people) could not stand without catching hould of ye posts & pails yt stood next them.”

Magnitude 6.5 earthquake centered in central New Hampshire (in Ebel, Seism. Res. Lett., 1996).

So powerfull is ye mighty hand of ye Lord, as to make both the earth & sea tremble before him”

The Charlevoix Earthquake of 1663The Charlevoix Earthquake of 1663

The largest known earthquake in The largest known earthquake in the northeastern U.S. and nearby the northeastern U.S. and nearby parts of Canadaparts of Canada

Shaking reported to have lasted Shaking reported to have lasted about 3 minutes and caused large about 3 minutes and caused large landslides and sandblowslandslides and sandblows

375 mi away in Boston, chimneys 375 mi away in Boston, chimneys fell, pewter fell from shelves and fell, pewter fell from shelves and many people ran into the streetsmany people ran into the streets

Aftershocks were felt in Quebec Aftershocks were felt in Quebec for more than 7 months.for more than 7 months.

M7.0 - M7.5 (?)

1727 Newbury Earthquake

The earthquake damaged chimneys and stone walls in Newbury, Massachusetts and nearby towns. It was felt to Philadelphia and Casco Bay, Maine.

Estimated magnitude: 5.6.

The Roman numerals on this plot are modified Mercalli intensities. MMI VI is minor damage, MMI VII is moderate damage, MMI VIII and higher is major damage.

Over 150 aftershocks documented.

The Great Cape Ann Earthquake of 1755

About 1/3 (1,200 to 1,500) of the chimneys in Boston were damaged, as were the brick walls of several buildings. Damage was reported from Portland, Maine to south of Boston. The shock was felt from Halifax, Nova Scotia to Winyah, South Carolina.

Estimated magnitude: 6.0 – 6.3

On November 20, 1755, the Boston Weekly News-Letter reported: "Last Tuesday Morning about half an Hour past Four o'Clock, the Weather being serene, the Air clear, the Moon shining very bright, we were surpriz'd with a most terrible Shock of an Earthquake: The conditions were so extreme as to wreck the Houses in this Town to such a degree that the Tops of many Chimnies, and some of them quite down to the Roofs, were thrown down. . . ."

“By a Person which came in Capt. Burnam, who arrived at Marblehead from Cadiz last Week, we learn that they felt the above Shock 70 leagues E of Cape Ann, at ½ Past 4, but concluded that they ran foul of a Wreck, or got upon a Bar, but on throwingOver the Lead, found they could not sound in 50 Fathom of Water, and continued Ignorant of what it was till morning, when to their great Surprise, they saw a vast Number of Fish, large as well as small, floating on the Water dead, when they concluded It could be nothing but an Earthquake…”

The Boston Gazette, or Country Journal newspaper of Nov 24, 1755 reported:

An illustration of the 1755 earthquake in Boston.

Most recent damaging earthquake in the northeastern U.S. was on June 23rd, 2010.

There was minor damage within about several kilometers of the epicenter. It was felt in Boston, New York, Buffalo and even Michigan.

Magnitude: 5.0.

Images from Jean Levac, Images from Jean Levac, The Ottawa Citizen, June 24, The Ottawa Citizen, June 24, 20102010

Major Earthquakes in the Northeastern U.S. and Southeastern Canada 1638-2010

Known or suspected earthquakes of magnitude 5.0 or greater in New England

Notable damaging earthquakes centered in New England in 1638, 1727, 1755, 1904 and 1940.

1638

1727

1755

1904

1940

1663

Thank you