Tuesday, February 7, 2012

The New Madrid Earthquake

February 7, 1812:
 The strongest in a series of earthquakes strikes New Madrid, Missouri.
February 7, 1812, 0945 UTC (4:45 a.m.); (M ~7.4–8.0[2]) epicenter near New Madrid, Missouri. New Madrid was destroyed. At St. Louis, Missouri, many houses were severely damaged, and their chimneys were toppled. This shock was definitively attributed to the Reelfoot Fault by Johnston and Schweig. Uplift along a segment of this reverse fault created temporary waterfalls on the Mississippi at Kentucky Bend, created waves that propagated upstream, and caused the formation of Reelfoot Lake by obstructing streams in what is now Lake County, Tennessee.
Some sections of the Mississippi River appeared to run backward for a short time. Sand blows were common throughout the area, and can still be seen from the air in cultivated fields. The shockwaves propagated efficiently through the firm midwestern bedrock, with residents as far away as Pittsburgh, Pennsylvania, and Norfolk, Virginia, awakened by intense shaking. Church bells were reported to ring as far as Boston, Massachusetts and York, Ontario (now Toronto), and sidewalks were reported to have been cracked and broken in Washington, D.C.  There were also reports of toppled chimneys in Maine.

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