New Madrid 1811-1812 Earthquakes

Info by popular demand:

Major earthquake felt in Iowa with large scale potential.

New Madrid 1811-1812 Earthquakes

USGS info page on the event:
http://earthquake.usgs.gov/earthquakes/states/events/1811-1812.php

Summary:

Three Main Shocks

1. December 16, 1811 - Magnitude ~7.7
2. January 23, 1812 - Magnitude ~ 7.5
3. February 7, 1812 - Magnitude ~ 7.7

Historical context:

It's happened before 1811-1812 The geologic record of pre-1811 earthquakes reveals that the New Madrid seismic zone has repeatedly produced sequences of major earthquakes, including several of magnitude 7 to 8, over the past 4,500 years.

Perspective:

1994 01 17 - Northridge, California - M 6.7 Fatalities 60