New Madrid - The Earthquakes of 1811 - 1812 - Natural Disaster Documentary Film

The 1811-- 1812 New Madrid quakes were an intense intraplate earthquake collection starting with an initial pair of large earthquakes on December 16, 1811. They stay one of the most powerful quakes to hit the eastern United States in recorded past. They, as well as the seismic area of their event, were named for the Mississippi River community of New Madrid, then component of the Louisiana Territory, now within Missouri.
There are quotes that the quakes were felt strongly over approximately 130,000 square kilometers (50,000 sq mi), and moderately throughout virtually 3 million square kilometers (1 million square miles). The 1906 San Francisco quake, by comparison, was felt reasonably over approximately 16,000 km2 (6,200 sq mi).
The underlying reason for the earthquakes is not well understood, but modern faulting appears to be associated with an ancient geologic feature buried under the Mississippi River alluvial level, called the Reelfoot Rift. The New Madrid Seismic Zone (NMSZ) is composed of reactivated faults that developed when what is now North America started to divide or rift apart during the separation of the supercontinent Rodinia in the Neoproterozoic Era (concerning 750 million years ago). Mistakes were created along the break and igneous rocks developed from lava that was being pressed towards the surface. The resulting rift system fell short but has continued to be as an aulacogen (a mark or area of weakness) deep underground.
The centers of over 4,000 earthquakes could be identified from seismic measurements taken since 1974. New forecasts estimate a 7 to 10 percent possibility, in the next 50 years, of a repeat of a major quake like those that occurred in 1811-- 1812, which likely had sizes of between 7.5 and 8.0. There is a 25 to 40 percent chance, in a 50-year time span, of a magnitude 6.0 or greater earthquake.