New Madrid seismic zone on the move. Huge gaps where whole streets disappear, emerged in late June 2011. Great movement begins the New Madrid fault line.
The upper reaches of the Mississippi, better known among geologists called the New Madrid Seismic Zone (NMSZ), form part of the rift — a fault line, which stretches for hundreds of kilometers, which in ancient geological epoch several times threatened to split the continent of North America. With the beginning of the Atlantic Ocean that possibility was ruled out. This "stop the crack", now known as Rilfutsky rift formed a depression, which later became the Mississippi River. Many large rivers flow through the planet in such a rift valley.
Most earthquakes in the United States east of the Rocky Mountains are in the NMSZ. Although such disasters are more common in western North America, the impact of the earthquake felt in a wide area of the Midwest. The reason is the large depth of faults, whereby the waves propagate over long distances.
"Scar tissue" faults and fractures around New Madrid is still a risk. Forecast to seismologists, new earthquakes in this area can occur at any time, and the probability of an earthquake of at least 8 points of the next 50 years, 10.7%.
Currently Mississippi River is densely populated. Memphis, Tennessee, and St. Louis, Missouri, to become a city, the population of which exceeds one million. Compared with other parts of the United States (California, for example), the modern buildings in these areas can not withstand strong earthquakes.
Tragedy in 1811.
In late 1811 — early 1812's DC experienced a series of aftershocks, each force 8 on the Richter scale. It began early in the morning of 16 December 1811 and in January-February next year, followed by two waves of earthquakes. The epicenter was near the town of New Madrid, located on the Mississippi River between the major cities of St. Louis and Natchez.
At the beginning of XIX century, the western boundary of the New World took place on the Mississippi, which, together with the Missouri form the largest river system in North America. Even at that time it was a busy transportation route, but suffered from the disaster areas were inhabited by little. For various historical data, at that time in New Madrid, lived from 400 to several thousand. In the disaster area were about 4000 people.
Eyewitnesses described how the earth opened, finely ground trembled, and in some places into thin sections, in others — the land rose. Some cracks stretched for several kilometers. This disaster is accompanied by thunderous roar and a shrill whistle. According to a witness, his horse "stood rooted to the spot and froze with fear. Trees were broken like matches, and toppled to the ground entire forests. The air was saturated with the smell of sulfur. "
"Around me everywhere from the land fountains of water several meters high — told another witness. — Earth shook so violently that I could barely stand. Appears small volcanoes where strong pressure squeezes out of melted water from the river sand. Craters could be seen everywhere, some were about four and a half feet deep. " Besides New Madrid suffered a small town of Little Prairie and Point Pleasant. The damage caused by the Little Prairie, was so great that the people were gone.
Due to subsidence in line Mississippi River briefly flowed backward. By tremors rang church bells in Boston, Massachusetts, remote from the epicenter of a thousand miles. This natural disaster, a serious study of which geologists began only in the second half of the XX century, coincided with the release of the first voyage on the Mississippi first steamship, who at the time headed the Ohio River to New Orleans. According to the team, the island to which the ship docked, the morning had disappeared underwater.
Over eight weeks, there have been three series of earthquakes and thousands of related shocks (aftershocks). They forever changed the landscape and the direction of Mississippi. Forests disappeared under the water and died, new lakes, such as Rilfut in Tennessee, St. Francis and Big Lake in Arkansas.
Although the New Madrid seismic activity and makes us think about many aspects of our lives, it does not oblige us to give up some of the joys of everyday life. For example, finding a suitable site where you can play slots for free without registration, there is a great chance for ponastalgirovat old days when it was necessary for it to pay coins in gambling halls.