Historical October 1990 earthquake supplement. Original predictions, insurance prices and safety guidance are reproduced as period reporting, not current forecasts or instructions.
The New Madrid Fault System, according to a Red Cross publication. is a “complex zone of seismically active fractures in bedrock several thousand feet beneath the Mississippi River’s sands and muds.
It runs 120 miles from southern Illinois, southwest, to northern Arkansas.
It is the only place in the Eastern U.S. capable of quakes measuring 6.0 or greater.
The fault has more than 200 shocks (1.0 or greater) each year, about 20 per month. Large tremors (2.5-3.0) are felt annually. Shocks of 5.0 or more occur about once in 10 years.
A damaging quake (6.0 or more) reoccurs in this area about every 80 years. Five earthquakes over 8.0, out of a total of 2000 shocks, erupted in the disastrous winter of 1811-12. Eighteen of these rang church bells on the Eastern seaboard.
Because the New Madrid Fault involves bedrock, the shock will travel much farther than a similar quake in the muddy earth of California’s San Andreas Fault.
Originally published in The Times of Skinker-DeBaliviere, October 1990.
Read this article in the original newspaper issue.
Archival transcription note: Source earthquake frequency, magnitude and “only place in Eastern U.S.” claims are historical claims not independently endorsed.
Original source: SD_Times1990_10.pdf, printed page(s) 3; PDF page(s) 3.
