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Signs of the Times #1465
New Data Confirms Strong Earthquake Risk to Central US [Jun 22] 'Strain is building on a fault near Memphis, Tennessee that was the site of a magnitude 8.1 earthquake in 1812. Such a strong earthquake would rock the entire eastern half of the country and prove devastating to the local region. In a three-month period in 1811-12, three major earthquakes rattled a broad expanse of the United States, causing damage as far away as Charleston, South Carolina and even rattling nerves in Boston. The quakes triggered landslides into the Mississippi River and, according to some boaters who were not drowned, sent part of the river running the other direction for a time. The earthquakes were centered around New Madrid, Missouri. They measured 8.1, 8.0 and 7.8 and represent three of the four strongest earthquakes ever recorded in the lower 48 states. Sandy soil in some areas became liquefied in past events. This tendency for soil east of the Rockies to liquefy, along with other differences in geology, means earthquakes there pack more potential for damage and are felt over a much wider region than western temblors.'
[and from another source] [Jun 23] 'At the surface, the Reelfoot fault is a gentle swell that runs from New Madrid, Mo., to northwest Tennessee through corn and soybean fields. It cracked in the huge New Madrid quakes of 1811-1812. The west side of the fault shot up, the other side down, as much as 10 feet. The sinking formed Reelfoot Lake and caused the Mississippi River, at least for a moment, to flow backward.' [and from another source] [Jun 22] 'It´s a 120-mile-long system of three to five faults stretching from 40 miles northwest of Memphis to southern Illinois, near Cairo. These quakes were felt keenly over more than 2 million square miles -- people in Boston, Massachusetts, felt one or more of the three main quakes, the first of which struck in three shocks on the morning of December 16, 1811. By contrast, the 1906 earthquake in San Francisco, California, was felt over 60,000 square miles. Whenever it occurs, the quake likely will be felt far from its epicenter. The one in 1968, centered in southeastern Illinois near the confluence of the Tennessee and Ohio rivers, caused moderate damage, but it was felt across 23 states -- as far as the Carolinas -- and into Canada.' [and from another source] [Jun 22] 'US scientists, reporting in the British science journal Nature on Thursday, say the New Madrid Seismic Zone is deforming rapidly, experiencing rates of strain that are similar to those in notoriously active plate boundaries.' [Note: liquifaction, where the ground becomes mushy, is a factor in New Madrid quakes, making them more deadly.]