This weekend's Downstate earthquake continues to rumble the Midwest. Over the past few days, 15 different afterquakes have registered with the U.S. Geological Survey. Almost 100 years ago, there was a series of earthquakes originating in the New Madrid fault:
Classified as "moderate," today's event caused some damage and was followed by aftershocks, the largest a M4.6 that occurred at 10:15 am Central Daylight Time. Of much greater concern, however, is the potential for the adjacent New Madrid seismic zone to generate severe earthquakes. During the winter of 1811-1812, a series of three very large earthquakes — the strongest earthquakes to strike the lower 48 states during historic times — devastated the area and were felt throughout most of the nation. Occurring only a few weeks apart on Dec. 16, Jan. 13, and Feb. 7, they generated hundreds of aftershocks, some severely damaging by themselves, which continued for years.
