Windows rattled, doors opened, wall pictures shook, beds moved, dinner dishes shuffled about and table flowers observably quaked, in Michigan's largest authentic earthquake. On the 9th of August 1947 at 9:47 P.M. rattling houses, buildings, windows and furnish-ings sent people rushing into the streets. The recorded one-minute 4.7 magnitude seismic activity traveled across southern Michigan from west to east in three minutes. Coldwater, Michigan was identified as the tremor's epicenter.
This 1947 quake may have been the biggest in modern history, but Michigan's reported quake history began in the seventeenth century when French missionaries in 1638 recorded the state's first earliest documented earthquake activity. In 1663, French missionaries again reported seismic shocks from an earthquake of great violence that rattled Michigan.
At the turn of the last century, earthquakes hit the Upper Peninsula's copper mining region. These seismic disturbances were probably due to the unstable conditions associated with mining that may have facilitated fault slippage. On the 26th of July 1905 a seismic event of Intensity VIII on the Mercalli Scale struck near Calumet and Lake Linden, Michigan. Around 6:30 P.M. a terrific explosion spawned tremors throughout the Keweenaw Peninsula and as far east as Marquette. The audible shocks of the quake � similar to a heavy train � tumbled most of the chimneys in Calumet and Lake Linden and broke many windows. One house reportedly moved about an inch off its foundation and a local drug store suffered floor damage from broken acid bottles.
In addition to Michigan-centered quakes, the Great Lake state has experienced numer-ous shocks and tremors from earthquakes in North America. The earliest recorded shock-waves felt in Michigan were those from the 1811-1812 Missouri earthquakes along the 120-mile New Madrid fault extending from Illinois to Arkansas. The largest of the quakes in December of 1811 was felt over a two million square-mile area from Canada to the Gulf of Mexico and from the Rocky Mountains to the Atlantic Seaboard. According to W.M. Herbert Hobbs, an early twentieth century Michigan geologist, the ground rose and fell as earth waves, like the long, low swell of the sea, passed across the surface and caused Orchard Lake in Oakland County, Michigan to boil, bubble, foam and roll about, causing great numbers of turtles to go ashore. Intermittent aftershocks followed until a second major quake from Missouri occurred on the 23rd of January 1812. In early February 1812 a third major quake from Missouri caused constant aftershocks for several days. Subsequent minor aftershocks lasted at least two years.
In the years after Missouri's New Madrid series, Michigan shook from several out-of-state earthquakes. On the 31st of October 1895 shocks from a seismic disturbance in Charleston, Missouri was felt in Michigan. In 1909 an Illinois earthquake jolted Michigan. Ohio earthquakes were felt in Michigan during 1937, 1943 and 1986. Another Illinois earthquake jarred Michigan in late 1968. Quakes from Quebec in 1988, Illinois in 1987, Kentucky in 1980, and Pennsylvania in 1998 also affected areas of Michigan.
In 1994 a 3.4 magnitude earthquake centered in the Lansing, Michigan area was felt. More recently, a smaller 2.9 magnitude quake occurred in Prairie Lake, Michigan in 2001.
Are there earthquakes in Michigan? Occasionally, though few have originated in Michigan. But the next time your windows rattle and break, buildings quake and items are displaced, don't dismiss that disturbance as a sonic boom or explosion. It just may be seismically related.
