TULSA - Two hundred years ago, in the winter of 1811-12, several of the most massive earthquakes in recorded history struck along what is called the New Madrid fault line, centered on southeast Missouri.
At the time, that area of the country -- including what is now Oklahoma -- was inhabited mainly by native Americans, and sparsely populated compared to the number of people living there now.
The New Madrid quakes began with two incredibly massive shocks on Dec. 16, 1811, spaced about six hours apart.
A number of strong aftershocks followed for months. Then, in February, 1812, the largest quake of all struck.
The amount of energy released is difficult to imagine.
Those quakes caused severe shaking across an area estimated to have been 50,000 square miles in size. They were moderately felt in an area roughly one million square miles in size.
By comparison, the infamous 1906 earthquake that flattened San Francisco was moderately felt over an area of about 6,000 square miles.
According to the U.S. Geological Survey , "The area of strong shaking associated with these shocks is two to three times as large as that of the 1964 Alaska earthquake and 10 times as large as that of the 1906 San Francisco earthquake."
The New Madrid quakes were reportedly felt by people in an area ranging from the Gulf of Mexico all the way to Canada. They toppled chimneys in Maine, rang church bells in Boston, cracked sidewalks in Washington, D.C.
They caused parts of the mighty MIssissippi River to run backwards, and created sand blows so massive they can still be seen from the air to this day.
The amount of damage that a series of quakes that size would cause in the modern southeastern United States can only be imagined.
A recent study by the University of Illinois indicates that more than 7,000,000 people would be homeless, hundreds of thousands dead and wounded, and the infrastructure of several states destroyed.
So is such a nightmare scenario possible? Unfortunately, some signs point to an increase in seismic activity in the area.
Arkansas has had more than 500 measureable earthquakes since October of last year.
When a 4.5-magnitude quake struck near Norman, Oklahoma last year 2NEWS learned that the state had had 215 quakes in the month of September, well above the average number.
Oklahoma usually experiences between 20 and 150 quakes per year.
On the bright side, the USGS says that such earthquake "swarms" do not necessarily indicate a heightened probability of a major tremblor.
Still, some seismologists warn that it's not a matter of "if" there will be another massive quake in the region, but rather "when."
Unfortunately, modern science still cannot predict earthquake activity with any degree of accuracy.