02/07/2017
Earthquakes in our neck of the woods.
On this day 205 years ago at approximately 3:45 a.m. local time, a magnitude ~7.5 earthquake struck western Tennessee and western Kentucky, southeast Missouri and northeast Arkansas. It was the last and likely the largest of the 1811-1812 sequence, which began with a comparably large earthquake on December 16, 1811. Boatmen on the Mississippi River reported waterfalls on the river probably near where the Reelfoot fault rupture crosses the river southeast of the town of New Madrid, Missouri.
This map shows earthquake epicenters M2.0 and larger since 1973, and the surface trace of the Reelfoot fault. (Credit: USGS)
The February 7 earthquake generated many aftershocks, including several that were around magnitude 5. The earthquake was clearly felt up to about 900 miles away along the Eastern Seaboard from New York to Savannah, Georgia. Chimneys were thrown down 350 miles away in Cincinnati, Ohio, and the shaking damaged chimneys over 500 miles away in Columbia, South Carolina President James Madison felt it in Washington D.C. and wrote about it in a letter to Thomas Jefferson. If a similar quake was to occur today, it would strongly impact the buildings where 12 million people now live and work in the St. Louis–Memphis region. Learn more about this event at https://on.doi.gov/2jMyNyG.
Learn what to do before, during, and after an earthquake at http://bit.ly/2gQD7Pn.