Tuesday, February 07, 2012

Elvis is Dead, and Memphis Ain't Far Behind

Two hundred years ago today, the last in a two-month series of four major earthquakes struck along what is now called the New Madrid Seismic Zone (NMSZ).  Each of the four quakes is estimated by seismologists to have been between 7.0 and 8.0 in intensity.  The first two struck on the 16th of December in 1811; the third on the 23rd of January in 1812.

They were accompanied by hundreds of aftershocks, dozens of which would have in their own rights been considered major.

The NMSZ lies along a mid-continent rift that geologists theorize was the result of a failed attempt by plate tectonics to pull the continent apart in pre-history.   Sediments of the Mississippi River alluvial plain cover a series of interlocking faults throughout a region of underlying bedrock and mantle weakened as a result of the failed rift.   

Unlike the obvious and much more active faults on the left coast, the New Madrid Seismic Zone (named for the only white settlement of any size in the region 200 years ago) is curiously inactive and obscure.  It rarely makes itself known beyond a scattered slight tremble.

Unfortunately, when it does announce its true capabilities, the NMSZ does so with unimaginable force and consequence.  And, the effects are felt over an unbelievably large area.  A quirk of geologic difference between the Western and Eastern sides of the North American Continent causes a great disparity in the "felt effects" of earthquakes as shown in the diagram below.


The 1811/1812 New Madrid earthquakes were felt as far away as present-day Toronto, Canada and caused damage to buildings and streets in cities along the Eastern Seaboard from Columbia, South Carolina to Washington, D.C. 

The shaking from one of the earthquakes is reported to have been strong enough to ring church bells in Boston. 

From geologic evidence of past earthquakes in the NMSZ, seismologists place the odds of a recurrence of an earthquake of the same magnitude as the 1811/1812 quakes at 10% within the next 50 years.  As it is with all of Creation's natural disasters (whether terrestrial or extra-terrestrial in origin), the occurrence of  a major quake in the Mid-South is not a matter of if, but when.  

When the next major quake (or series of quakes) strikes the NMSZ, it will cause damage and loss of life unparalleled in the history of our nation, or any nation for that matter.

The city of Memphis did not exist when the earthquakes struck 200 years ago. 

It will not exist after the next one.  

The extent to which critical infrastructure elements will be effected is far greater than the patience of the thousands of you who liberally partake of the barely literate literary libations ladled out hereon can stand the telling.  Here's just one example: 

Every rail and road bridge across the Mississippi River from St. Louis to Greenville, Mississippi will be, if not outright destroyed, rendered unusable.  Memphis is a critical node in the distribution systems for many major corporations.  Disruptions in interstate trade will visit material hardship on the entire continent and could easily plunge the nation into economic depression.

That's the good news.

The bad news is that, instead of focusing the Department of Homeland Security on measures to mitigate this real threat (and others like it) to the well-being of the American people, our federal government is more concerned with punishing the American people for the actions of 19 jihadists on 9/11.   

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