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What is unusual about the New Madrid Seismic Zone?

Unlike the West Coast where major quake activity is more predictable based on measured movement at tectonic plate boundaries, New Madrid is located near the center of the North American Plate. Shake and damage areas are up to 20 times larger than similar West Coast quakes. Earthquakes cannot be predicted.

When was the last time the New Madrid fault was active?

It was December 16, 1811, and it was the first of at least three very large (M7 or greater) earthquakes and thousands of aftershocks to rock the region that winter, with the last occurring on February 7, 1812.

What causes the New Madrid Seismic Zone?

During the process of continental rifting, a deep valley formed that is bounded by faults and known as the Reelfoot rift. New Madrid seismicity is spatially associated with the Reelfoot rift and may be produced by movement on old faults in response to compressive stress related to plate motions.

What created the New Madrid fault zone?

New Madrid earthquakes of 1811–12 Encyclopædia Britannica, Inc. Some Earth scientists suggest that fracturing in this region resulted from stresses brought on by the downcutting of the Mississippi River into the surrounding landscape between 10,000 and 16,000 years ago.

What caused the New Madrid Seismic Zone?

How likely is a New Madrid seismic earthquake?

And how likely is it? Seismologists estimate that the New Madrid Seismic Zone has a 25 percent to 40 percent chance of producing a significant quake within the next 50 years, according to Lexington-Fayette Urban County Government.

How was the New Madrid fault formed?

The New Madrid Fault Zone is part of an ancient plate boundary. In this area, the North American Plate tried to form a divergent plate boundary about 500 million years ago. The splitting stopped before new plates could form. Earthquakes occur because the North American Plate is still “settling down”.

What caused the New Madrid earthquakes?

The main shock that occurred at 2:15 am on December 16, 1811, was a result of slippage along the Cottonwood Grove Fault in northeastern Arkansas. It was followed by at least three large aftershocks with magnitudes that ranged from 6.0 to 7.0 over the course of the next 48 hours.

What will happen when San Andreas Fault?

Death and damage About 1,800 people could die in a hypothetical 7.8 earthquake on the San Andreas fault — that’s according to a scenario published by the USGS called the ShakeOut. More than 900 people could die in fires, more than 600 in building damage or collapse, and more than 150 in transportation accidents.

Where is the New Madrid seismic zone located?

The New Madrid seismic zone is located in the northern part of what has been called the Mississippi embayment. The Mississippi embayment is a broad trough filled with marine sedimentary rocks about 50-100 millions years old and river sediments less than 5 millions years old.

When was the first earthquake in New Madrid?

New Madrid Seismic Zone 1 The Earthquakes of 1811-12. It was December 16, 1811, and it was the first of at least three very large (M7 or greater) earthquakes and thousands of aftershocks to rock 2 The New Madrid Seismic Zone. 3 Potential Dangers. 4 New Madrid Seismic Zone Related Links.

How did the New Madrid earthquake affect the Mississippi River?

In the New Madrid region, the earthquakes dramatically affected the landscape. They caused bank failures along the Mississippi River, landslides along Chickasaw Bluffs in Kentucky and Tennessee, and uplift and subsidence of large tracts of land in the Mississippi River floodplain.

What kind of artifacts are found in New Madrid?

Photograph of some diagnostic artifact types in New Madrid region: 1, Campbell Appliqué; 2, Bell Plain; 3, Nodena Elliptical point; 4, Nodena Banks variety point; 5, Parkin Punctate; 6, Madison point; 7, Varney Red Filmed; 8, Barnes Cord Marked; 9, daub with wattle impression.