Monitoring the New Madrid Seismic Zone
The New Madrid Seismic Zone remains one of the most active in the United States, averaging approximately 200 quakes measured at 1.5 or more each year. Scientists say the chance of an earthquake measuring 7 or more in the next 50 years is 7-10%. The chance of an earthquake measuring 6 or greater in that time is three to four times higher.
If you’re nervous about that next big one, or just curious, you can monitor what’s happening in the NMSZ each day at http://www.new-madrid.mo.us/index.aspx?NID=105. This New Madrid site gives you monthly summaries of the time, measurement, location, and hypocentral depth of the quakes.
Five micro quakes (ranging from .9 to 1.3) occurred during the first four days of September, three of them 6.8 miles SSW of New Madrid. The other two were near Lilbourn, MO, and Ridgely, TN.
Several quakes in August were more powerful. They included a 2.5 event 4.35 miles NW of Tiptonville, TN (near Reelfoot Lake), a 2.4 event 8 miles WSW of Albion, IL, and a 2.4 event 4.8 miles ESE of Manila, AR.
No one seems to know when the big one(s) will come, but apparently the little ones never stop.
—Carolyn Mulford