The Explainer General
There were no scientific instruments to measure the New Madrid Quakes in 1812 so geologists have sifted through widespread accounts from old journals and newspapers for data. Putting the accounts together on a map, we know the quakes were felt over an area of 1,930,000 square miles. They earthquakes began with a pair of terrific shocks at 2:15 and 7:15 local time on the morning of December 16, 1811, both measuring 7.2 - 8.1 on the Richter scale. They were followed by a 7.0 - 7.8 quake on January 23, 1812, and a 7.4 - 8.0 event on February 7, 1912.
The quakes were violent, earth-shifting events. There have been even more powerful earthquakes in Alaska and Hawaii, both vulnerable to deep geological pressures, but the New Madrid quakes are the largest to ever occur in the original forty-eight states. Yet little damage or loss of life was reported. The region was then part of Louisiana Territory, sparsely inhabited with small villages and only a few multi-story masonry buildings. We can’t know how many log cabins or small home chimneys were thrown down, or how many Native Americans were affected.
Coincidentally, the first steam paddle-wheeler on the Mississippi, the New Orleans, invented by Robert Fulton, was making its first trip south during the quakes. Land heaves caused massive waves to travel up and down the river. When the little southbound New Orleans met one of these waves it seemed that the great Mississippi was running backward. Some land rose, riverbanks crumbled, some land subsided and formed new lakes. The river’s course was so changed that maps were useless, and the steamboat did a remarkable job of “feeling its way” through the new channels to dock at New Orleans on January 10, 1812.
We’ve come to expect earthquake and volcanic activity around the Pacific “Ring of Fire,” and other hot-spots of geologic shift, but the New Madrid Quake was the product of an unexpected fault in earth’s crust we now call the New Madrid Seismic Zone. And, yes, there is the possibility of similar earthquakes from this zone in the future. The Earth that seems so solid is secretly restless.
Jan Adkins is not only a writer, but also a wonderful illustrator. His personal website is under construction at the moment, but if you would like to find out more about him and see a list of his very well known books, click here.
Sure, Roald Amundsen is credited with leading the first expedition to reach the South Pole, but there is some controversy -- perhaps real, perhaps sour grapes. Jim Whiting will explain tomorrow as we approach the 103rd anniversary of Amundsen's arrival at the Pole.