#MIHistory – Aug. 10: Michigan Earthquakes

On this day in 1947, a 4.6-magnitude earthquake hit Southeast Michigan, shaking Branch County the strongest. It’s believed to have been the strongest earthquake to hit Michigan in modern times. However, a 4.2-magnitude quake shook Michigan on May 2 of this year.

Map of seismic risk in Michigan, courtesy of U.S. Geological Survey.

Map of seismic risk in Michigan, courtesy of U.S. Geological Survey.

The earthquake of August 1947 damaged chimneys and cracked plaster over a large area of south-central Michigan and affected a total area of about 50,000 square miles, including points north to Muskegon and Saginaw and parts of Illinois, Indiana, and Wisconsin. The cities of Athens, Bronson, Coldwater, Colon, Matteson Lake, Sherwood, and Union City in the south-central part of the state all experienced shaking and damage. Reports of damage to chimneys and some instances of cracked or fallen plaster, broken windows and merchandise thrown from store shelves were common over the epicentral area.

The quake of May 2 rivaled the 1947 quake and was located in the same general area. Scientists now believe that both the 1947 quake and the recent earthquake both occurred on the same, previously unknown fault line. However, a third quake – a 3.3 temblor that struck 20 miles away from the May 2 quake – is not believed to be on the same fault line.

The earliest record of earthquake tremors felt in Michigan Territory were from the great series of shocks centered near New Madrid, Mo., in 1811 and 1812. As many as nine tremors from the New Madrid earthquake series were felt in Detroit.

A damaging earthquake, apparently centered between Montreal and Quebec in the St. Lawrence Valley, occurred on Oct. 20, 1870. This shock was felt over an area estimated to be at least a million square miles, including Sault Ste. Marie.

Between 1872 and 1883, a number of moderate earthquakes were centered within Michigan. On Feb. 6, 1872, three shocks lasting 30 seconds were reported at Wenona. No additional information is known about these tremors. Reports from Redford and Greenfield Village, not far from Detroit, indicated a minor earthquake occurred on Aug. 17, 1877. It was noted that horses were frightened during this shock. Some persons reported hearing a noise like a train. On Feb. 4, 1883, an earthquake cracked windows and shook buildings at Kalamazoo. This shock was felt in southern Michigan and northern Indiana. Cities as distant as Bloomington, Ill., and St. Louis, Mo., also reported feeling this earthquake.

A number of other earthquakes centered outside the state have been felt in Michigan. Noteworthy among these are the following:

  • Feb. 28, 1925
    St. Lawrence River region northwest of Murray Bay (La Malbaie), Quebec, Canada; felt in Grand Rapids, Newberry and Whitefish Point.
  • Nov. 1, 1935
    Timiskaming, Quebec, Canada; Felt in Alpena, Hillman, Mount Clemens, Pellston and Port Huron.
  • March 2 and 8, 1937
    Western Ohio; 150,000-square-mile felt area at many places in southern Michigan.
  • Sept. 4, 1944
    St. Lawrence River region between Massena, N.Y., and Cornwall, Ont., Canada; felt in Alpena, Detroit, Grand Rapids, Lansing, Saginaw and Sault Ste. Marie.
  • Nov. 9, 1968
    South-central Illinois; felt throughout southern Michigan.

 

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