Clear Waters From Clear Fork River

Notice the V-Shaped Valley in the upper left corner
There is a creek that runs through there and will empty into
the Clear Fork of the Cumberland River just
downstream from here.

Many people have a river or creek that runs through their village, town or city.  Especially if they live in Karstic regions in moderate zones.  Take, for example, the Ozark Plateau or the Ouachita Mountains in Arkansas along with, Southeast Kentucky and Northeast Tennessee, down the western slopes of the Southern Appalachian Mountains! 

But what if there are some rapids like the image to the left, the "Train Wreck Rapids," as it is affectionately known by whitewater enthusiasts, that is on the river or stream that is floating by? The Clear Fork of the Cumberland River is no exception to the rules that many other Karstic rivers have.

Map of the Clear Fork Basin

The Ouachita Mountains of Arkansas has ridges that run east to west.  This is why rivers generally flow eastward there.  The Appalachian Mountains has a series of ridges that run southwest to northeast. It would make sense that rivers in this area will flow downhill following these paths.  Of course, rivers will form valleys by cutting their beds, moving sediments downstream, changing courses over time, creating their own little flood valley.  

Erosion is taking place here.
Notice how the rainwater over many years have
cut through the ground, creating it's own
stream-bed.  This may become a stream one of
these days!

Clear Fork starts in Bell County, Kentucky, where Tennessee and Virginia border in the southeast corner.  This would make it real close to the Cumberland Gap.  The river runs southwest to west southwest, (which tells us that the elevation is getting lower in this direction) entering the state of Tennessee, where it continues to flow in a southwesterly direction and then curves to the west and northwest.  When the river starts to flow northerly, there must be a ridge just to the south of where the river bends.  There is an opening to the west that is lower than the south, therefore, Clear Fork will take a westerly then a northerly direction, as it continues to go downhill.  Clear Fork reenters the State of Kentucky in the county just to the west of it's origin, Whitley County.  Here, the river flows into the Cumberland, just east of Williamsburg, the county seat.

A road runs right by the Clear Fork (to the right of the road).
The cliff face to the left was made by human activity
when creating a path for this road.

The Clear Fork River, right before flowing into the
Cumberland River just east of Williamsburg, KY

In Claibourne County, Tennessee, there is a city that sits where Interstate 75 goes north into Kentucky (also where the river is).  This town is Jellico and it is the home of the Clear Fork Watershed Council.  I know, because I have a cousin, Derek Douglas, who is heavily involved with that Community Organization.  It is he, that I must thank for posting these fascinating photos, which he so kindly allows me to publish here!  For more information, please visit their facebook page, 

https://www.facebook.com/pages/Clear-Fork-Watershed-Council/141815149225594

That's a nice looking cliff face! I can tell that it has gone through it's share of erosion. That "tannish" color was recent, where the rock fell out. Eventually, it will turn into the bluish-gray, blending with the surroundings. I notice to that the top extends further out above the road than the bottom does. When its freezing, the water that runs through these rocks will turn to ice.  When this happens on a continual basis (freezing, thawing, freezing, thawing, etc.), the rock formation will eventually break because of the stress, causing this discoloration to occur.  From this photo, I can tell there is a lot of limestone in the area, so this is definitely Karstic, with it's share of spring-fed creeks and streams, along with numerous caves.

Thanks!
Jack Douglas

The New Madrid Earthquakes

Reelfoot Rift Zone

The Reelfoot Rift Zone has its biggest concentration in parts of 5 states which are:  Northeast Arkansas, Southwest Illinois, Western Kentucky, Southeast Missouri, Western Tennessee; even extending into Northern Mississippi.

It is here where the famous series of earthquakes during the winter of 1811-1812 rang church bells as far away as Boston and damaged scaffolds at the capitol building in Washington, D.C.  One of these earthquakes even made the mighty Mississippi flow backwards for a few hours, causing the lake “Reelfoot” which got its name from the seismic zone that made it happen!

General Plate Tectonics

Most earthquakes in the United States occur in Alaska and California.  These states are associated with the North American and the Pacific Plate boundaries, along with Oregon and Washington.  At this boundary, the heavier crust of the Pacific Ocean goes underneath the lighter crust of the North American plate.  This causes tension and rocks underneath North America get crushed and melted, causing geologic structures such as mountains and volcanoes, which is exactly what is going on over there.  First, it was the Rocky Mountains.  As North America continued to push and expand westward, the Sierra Nevada Mountains and the Coast Ranges were formed.

On the other side of the North American Plate is the Atlantic Rift, in which the plate is moving away from the Eurasian Plate.  Likewise, the Eurasian Plate is moving further away from North America and going towards the Pacific Ocean to the East.  The rift between North America and the Eurasian plates has caused the crust to split open and magma from underneath to surface upward, creating the Mid-Atlantic Ridge which is an undersea Mountain range going north to south right at the center of the ocean.  It is this rift that fuels the volcanoes in Iceland.  Iceland is a part of that ridge that extends above sea level.  It would be fair to say that the Atlantic Ocean is getting wider as the Pacific is shrinking.

Neither the plate boundary of the West Coast of the US, nor the Atlantic Rift underneath that ocean has anything to do with what is taking place in the central part of the country, where there are no current plate boundaries.  Note the word “current.”  It is believed that at one time (a very long time ago—before the time all the continents were one, the Pangaea), the North American plate was ripping itself up in Southeast Missouri, hence the name “rift.”  This rift never fully completed, (it never ripped open the surface) so geologists today consider this rift zone a “failed” one.  Yet, it is so deep below the surface and the tear is significant enough to cause this area to be a great seismic risk-hazard zone.  All this means is simply, earthquakes do happen in the middle of the country, where there are no plate boundaries and because of that, a greater area may have significant damage than areas that are prone to earthquakes due to crustal boundaries (like the Pacific Coast).  Why is this?

Impacts of Mid-Continent Earthquakes

The map on this page compares the Northridge Earthquake that damaged Northwest Los Angeles in 1994 to an earthquake that occurred at Charleston, MO in 1895.  Even though the LA earthquake was stronger than the Mid-continent one, the area of damage is relatively much smaller.  Again, why is this?  Notice at the West Coast, earthquakes happen much more frequently there because of plate boundaries.  Therefore, the ground below the surface is cracked, always being recycled and comparatively “newer.”   Earthquakes in Missouri, on the other hand, happen with less frequency, the ground is not being continually recycled and is much more brittle, “older.”  This causes surface waves of an earthquake to move with better effectiveness; hence, an earthquake here in the center of the continent will affect a bigger amount of area as the above map shows.

 http://upload.wikimedia.org/wikipedia/en/c/cb/Charleston1895.gif

What does this mean for the future? 

There is at least a 90% chance that an earthquake similar or more potent than the ones during the early nineteenth century could occur here in the rift zone by 2050.  That doesn't really give us much time, really.  These earthquakes could indeed happen in the next 35 or 40 years, but then again, could happen tomorrow.  The 1811-1812 New Madrid Earthquakes didn't cause so much death and destruction, mainly because the immediate area was sparsely populated.  Now, we have quite a few major cities that will no doubt suffer extensive amount of damage, like Memphis or St. Louis.  Other cities that may be profoundly affected would be Nashville, Louisville, Little Rock.  Even Northwest Arkansas could receive an extensive amount of damage even though it is 350 miles away!  Something to think about!  Be prepared, because the government has done a bang up job so far, considering that fiasco called "Katrina!"  Well, maybe we have learned our lesson thus far.  The aftermath of Sandy was much smoother!