Repeat of the New Madrid Earthquake of 1811 Would be Worst Natural Distaster in U.S. History

If another quake of the magnitude of the New Madrid Quake of 1811 should hit the Midwest, it would be the worst natural disaster in American history. Overall the loss of life could run into the hundreds of thousands. 

The 5.2 magnitude earthquake that hit the Midwest last Friday was felt from Kansas to Georgia, and aftershocks have continued over the weekend, However, according to geophysicists, the aftershocks could continue for months, emanating from the nation’s center, known to be a weird seismic locale.

 

Residents of Mount Carmel, Illinois, are not surprisingly, a little jittery. The epicenter focuses on the northern extension of the New Madrid fault line, 6 miles north of Mt. Carmel, and is the same fault responsible for the devastating quakes of 1811 and 1812 in the Mississippi Valley. Actually, the 1811-1812 earthquake was a continuation in a series which included quakes in 1699, 1776, 1779, 1792, 1795, and 1804.

They are among the earthquakes of known history, affecting the topography more than any other earthquake on the North American continent. Judging from their effects, they were of a magnitude of 8.0 or higher on the Richter Scale, and were felt over the entire United States outside of the Pacific coast

For a long time now, scientists and locals have wondered when the fault line would strike again.

"I think we saw a window to this possibility today in the Wabash Valley," said geophysicist Allessandro Forte of the Université du Québec à Montréal, who has studied the region's seismicity. "It's to the north of the New Madrid seismic zone, but given the strength of crust, the stress can be distributed great distances. It's not clear if we could see something in the next few years or even next few months, I would say."

Measuring earthquakes is a tricky business. The last earthquake in the region close to Friday’s, measured in at 5.0 back in 2002. However back in 1968 a quake with a magnitude of 5.3 struck, and though there was only a .1 difference, this quake was felt in 23 states, including Ontario and Boston.

This most recent quake portends two different scenarios; one, that the small quake has relieved some of the geological stress and will see a cool down for the next few decades, or two…

"There is the possibility, and we can only see over next few months what will happen, that the redistribution of stress on neighboring faults might trigger further earthquakes, and we can only guess as to whether they'll be equally large as today's earthquake," Forte said.

"If we are seeing a propagation outward of stress changes after today's 5.2, which was a big one, and those stress changes finally come up on a fault which is on a hair trigger and ready to go, those small changes are sufficient to generate another big one on a fault which is locked and ready to go," Forte added.

As for looking for a figure, a percentage, on the chances of a large quake hitting the region over the next few decades? Good luck! Expert opinions range from a 90 percent chance, to a 25 – 40% chance, to between 7 and 10%.

 

Needless to say, Forte mentions that "This is not exactly a well-defined science as yet.”

Posted by Josh Hill with Casey Kazan

Links:

http://hsv.com/genlintr/newmadrd/accnt2.htm

http://www.livescience.com/environment/080418-new-madrid-update.html

Comments

[fiddle-fart]

there are many other factors beside bedrock that can cause the earthquake magnitude to amplify.
I live within miles of louisville, ky. and the major factor is that this city is ontop of a aquifier, which simply put is a wet sandy loam.
I'm no scientist, but just like the killer mexico city earthquake a few yrs. ago that the epicenter was in acapulco,several hundred miles away. mexico city is built on a dried lake bed.
so what i'm saying is always be prepared, have an emergency plan, and know where your shut-offs are.
more info can be found at
http://www.fema.gov/hazard/earthquake/index.shtm

[Chris Roberts]

I live in Searcy AR. I wondering if you could tell me what kind of damage I should be expecting if the New Madrid quake was to hit big. Thanks

[scientist.g.ponmudi]

land is rising and the rising of land is responsible for earthquake.

The earthquake that shook the new Madrid city from December 1811 to February 1812, still remain a scientific mystery.

Currently researchers believe that earthquake is an effect of rubbing of moving continental plates.

But the problem is the city new Madrid is located at the central part of the North American continent.

During the earthquake rising of some section of land created six foot waterfalls in the Mississippi river . And the land in the nearby city called as Tennessee uplifted, about 50 kilometers long and 23 kilometers wide.

This rising of land changed the course of the Mississippi river permanently.

Therefore I conclude that the earthquake was caused by the rising of the land.

sinse the earthquake zone is situated at the central part of the continent the so called moving of continental plates can not be said as an explanation.

it should be noted that when an earthquake occurred on 30.09.1993 in the killari village which is located at the central part of the peninsular India , land has been raised up to three feet hight and the rising of land has been observed up to two kilometer distance.

therefore the rising of land is the only reason for the earthquake.