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

Geologic Hazards: Sinkholes

In wake of a recent tragedy near Tampa, FL last week, the country reels back and realizes that sinkholes can become deadly.  There are three known deaths in Florida due to sinkholes throughout the state's history, so fatality isn't really associated with this phenomenon.  However, loss of life can and does occur.  What is more, sinkholes are associated with karstic topography, thereby making up 10-15% of the total Earth's surface that are prone to these hazards, as the purple areas on the Circle of Blue map shows. 

Map taken from "Circle of Blue"

The United States Geological Survey (USGS) define sinkholes as, "an area of ground that has no natural external surface drainage--when it rains, all of the water stays inside the sinkhole and typically drains into the subsurface. Sinkholes can vary from a few feet to hundreds of acres and from less than 1 to more than 100 feet deep. Some are shaped like shallow bowls or saucers whereas others have vertical walls; some hold water and form natural ponds. Typically, sinkholes form so slowly that little change is noticeable, but they can form suddenly when a collapse occurs. Such a collapse can have a dramatic effect if it occurs in an urban setting."

Map taken from: Northeastern University

On the map from Northeastern University, the green colors (both light and dark shades) represents areas with carbonate rocks underlying the ground.  This is typical of karstic topography, because karstic rock is sediments such as limestone and dolomite embedded into the bedrock.  These dissolve with rain water because the acid in the precipitation reacts with the carbons in those rocks.  This explains the large amount of caves inside karstic areas.  Note Eastern United States and the look at Florida.  The Ozarks of the Central US has also this danger.

Image taken from CBS News

Tropical storms and hurricanes can dump a lot of precipitation on a localized area.  If underneath that area lies a limestone cavern, the top of that cave could collapse, causing these sinkholes.  In June of 2010, one such storm did just that in Guatemala, causing a deep sinkhole.  A photograph from CBS News looks "photo-shopped," but is indeed an accurate picture of what happened there.  A massive hole like that could definitely swallow automobiles and buildings, with damages excessive in terms of money and human lives.  

Urban sprawl is also a culprit in the making of sinkholes.  When urbanized regions become really built up, the land has to support more weight.  The bigger the cavern underground, the less support the ground has.  The ground sinks because it cannot support the weight above the surface.  Because of these urban sprawl and tropical storms along with having a karstic underground, Florida more sinkholes than any other state.

Image taken from USGS

A big concern of sinkholes is flooding.  Often times a new pond that just appears is a sign that a sinkhole is on its way of being formed, because a depression in the land occurs before the collapse.  If someone is building a house on level ground that person may not know that he or she is building upon a future sinkhole.  Some time later, a depression forms and rainwater will naturally collect there, having no other place to drain off to.  This causes more weight upon the unstable surface and a positive feedback is made, where one thing leads to another and then the inevitable occurs.  The ground literally caves in, slowly at first, but more and more things happen that will quicken the process.

Image taken from "About Geology"

Flooding also occurs because of what is happening underneath the surface.  Rainwater dissolves the carbonates, forming caverns underneath the ground.  As a result, there is no place for the water to escape to and gets trapped down there.  Through the process of erosion, water essentially gets blocked in with no drainage to get out.  When a sinkhole forms, a pond may appear as water comes back above the surface due to the sunken ground, called subsidence, forces the water up.

Because depressions are a usual sign of a sinkhole, people naturally uses these geological features as a pit to throw garbage in.  This is also an environmental hazard because it could very easily contaminate the local drinking water supply.  This is why many communities have laws regarding what and where one could dump wastes. This is also a reason why many landfills today in America are heavily regulated.  Illegal dumps can also cause blockage of water, so it cannot drain out.  The unsupported ground has that much more weight and collapses.  Again, positive feedback is in play here.  

The scientists at "How Stuff Works" have this to say in how to detect if a sinkhole may be forming around the house that one is buying.  "Property damage, especially around the foundation, may be a subtle sign that something is wrong. In addition, if vegetation is dying unexpectedly, a sinkhole may have disrupted underlying streams that usually feed the plants. Other signs to look for include polluted or muddied well water, formation of new ponds and trees, or sign posts that appear to be slumping over."

Image taken from "How Stuff Works"

Of course, no one should buy property to live on if the neighborhood looks like swiss cheese!  Often times though, potential geologic hazards do not present themselves as obvious as the above image.  If it did, life for many would be much smoother.  Yes, that is safer, but ultimately, where is the fun in that?  Oh, yeah.  investments and capital interests.  Got it.  Maybe information such as this is important after all!

What is Karst?

Karst is a specific land-form that is made from mainly carbonic rocks which slowly dissolves when exposed to slightly acidic water.  This is why Karstic landforms feature so many caves and sinkholes.  Other unique features include sunken streams (which resurfaces later on, sometimes miles away from sinking under), numerous springs (often times from streams resurfacing) and rolling hills alongside deep valleys (even though the rocks underneath may not be “folded”).

 (Geology Cafe)

We got the name “Karst” from the German “Karst.”  Karst, in German, comes from the Slovakian “Krass,” which is the name of a region in the Slovakian Republic that has many karstic features and is indeed Karstic.

What exactly causes an area to have these features such as caves and sinkholes?  It is basically carbon chemistry.  When slightly acidic water comes in contact with carbonic materials on bedrock, the carbons dissolve in the water.  The water sinks quickly down to the ground, dissolving other carbonic material that gets in the way.  Before long, holes (aka caverns or caves) are created under the surface.  Eventually, the roof of these caves will collapse. Above ground, this collapse is seen as a “sinkhole.”

Ten to fifteen percent of the Earth’s surface has this type of landform as the map from Flatrock.org will show (flatrock.org).  

Unfortunately, millions of people around the world populate karstic regions around the world.  This is does cause some environmental hazards. These hazards include sinkholes.  When a large cave collapses, sinkholes big enough to swallow houses and buildings could easily form very quickly and without warning.  Farmlands could be lost forever.

There is, however, another hazard associated with Karstic regions that really needs to be considered here.  That is the water filtering system underneath the population.  Water goes through the ground much quicker in Karstic areas, bypassing the normal filtering system that cleanses the water from many things that would contaminate it.  Water drawn up from a well could easily get polluted by a nearby septic tank that is leaking everywhere, or by fuel tanks up the road underneath the filling station there.  Loss of fresh clean water is a serious hazard!  Unfortunately, in a lot of Karstic areas, sinkholes are used as dumping grounds for garbage.  If it rains, you can bet that the groundwater is NOT going to be potable!

(Geography)

In the United States, Karstic areas are all over the place.  Major areas include the Appalachian Mountains in the Eastern U.S., the Ozark Plateau in the Mid-South, Southern Rocky Mountains in New Mexico, Edwards Plateau in Central Texas and just about the whole northern half of Florida.  On this blog page, I will concentrate on the first two (mainly the Ozarks, but a lot of the Appalachians as well), though I will also go elsewhere to see what all I can find.  

I personally love the Ozarks.  My family has lived in or at the edge of this plateau for about 6 generations now.  I also have ancestral roots going to the Southern Appalachians (like Tennessee and North Carolina).  This blog page is only a small part of a much bigger research into my family background.  However, information presented here will be general enough to where I can easily share the information and have others interested in matters of history, geology, anthropology, geography, meteorology, sociology, climatology and other fields thoroughly enjoy the material.   

Enjoy!

Bibliography

(n.d.). Retrieved February 16, 2013, from Geology Cafe: www.geologycafe.com

(n.d.). Retrieved February 16, 2013, from flatrock.org: http://images.search.yahoo.com/r/_ylt=A0PDoV7o2B9RElIAsk.jzbkF;_ylu=X3oDMTBtdXBkbHJyBHNlYwNmcC1hdHRyaWIEc2xrA3J1cmw-/SIG=12t9cumal/EXP=1361070440/**http%3a//flatrock.org.nz/archive/2011/Jul/30/a_la_recherche_du_temps_perdu/

Geography. (n.d.). Retrieved February 16, 2013, from Ohio Wesleyan University: www.owu.edu