Current Calanques
As discussed in the last several blogs, Calanques National Park is located
in a coastal area in Southern France at the eastern edge of the city
Marseilles. Part of the Park is in the Mediterranean Sea and the rest of it was
formed under the sea many years ago. The primary material in Calanques is
Calcium Carbonate Limestone(CaCO3) made up of small plant and animal remains
concreted together making it a Karst formation. This Karst landscape
deteriorates through chemical weathering leaving rugged looking formations.
This chemical process occurs when H2O combines with the CaCO3 and creates
carbonic acids that decay the rock. This along with physical weathering
processes such as wind(wimpy), water, and gravity have created the conditions
of today and will continue to influence the future landscape in Calanques
National Park. Wind is a constant factor in the climate of the region. It is a
hub for several different kinds of wind.
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| As seen in this graphic there are caves, joints and fissures in the karst landscape. Many different limestone formations can be made in these caves and cracks, but more than anything there is dissolution and breakdown occuring in this type of coastal karst location. |
1000 Years in the Future
In Karst formations there can be fissures in the rock where water can
infiltrate. When this happens the chemical decay from this water inside the
Calcium Carbonate makes that fissure larger and creates new cracks and
weaknesses in the rock as well with the carbonic acids created. The water is
trying to get to base level by taking whatever route it can. These fissures may
be the easiest way. There may be large sinkhole events, due to this process, as
has been seen in many other areas made of Limestone. The caves in the limestone
from 2012 will become much larger and the ground above may collapse through
them. If it is a large enough occurrence, the sea may be able to inundate this
sinkhole.
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| This is a sinkhole with moving tides underneith. This began as a cave system under the surface, but as the limestone wore away there was less structure holding up the ground above and it eventually fell through. |
10,000 Years in the Future
Within 10,000 years the sea levels may be considerably higher or considerably lower depending on how Earth’s climates change in that time. 10,000 years ago the last large scale ice age was ending. Since then there is evidence of many climate changes including warming periods and cooling periods.
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| This graph shows mini-ice ages and warming periods over the last 10,000 years. If this graph were reversed to show the next 10,000 years and there were another ice age climates would be considerably different throughout Earth. This would also effect the sea levels causing them to recede because waters would be replaced in glaciers and ice caps. |
In 10,000 years the physical changes
to the environment will be noticeable. There will be decay to the rock from the
chemical and physical processes that are occurring in 2012. The rains, streams
and rivers coming through the National Park will continue to deteriorate the
limestone. The fluvial(river) processes and gravity constantly erode material and
deposit it in the Mediterranean Sea.
1,000,000
Years in the Future
In 1,000,000 years the narrow inlets of the Calanques will
have expanded by this time to create wide bays. These valleys grow faster than
normal valleys due to the normal weathering and the dissolution working
together. Much of the landscape that is showing now will have depleted and been
re-deposited in the sea possibly making the shoreline recede.
Material is constantly being taken from elevation and moving down towards base level along with water. This erosion is part of a cyclical process of build-up and breakdown. Since limestone is a rock that decays comparably quickly to some other rocks, 1,000,000 years will have substantial effects on the Calanques.
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| This is an example of one of the narrow Calanques that has already eroded away large amounts of the limstone and created a wider valley. Most of the Calanques are narrower valley, but they are all working towards the same fate. Eventually the landscape seen here will wear away and be deposited under the nearby sea. |
Conclusion
Material is constantly being taken from elevation and moving down towards base level along with water. This erosion is part of a cyclical process of build-up and breakdown. Since limestone is a rock that decays comparably quickly to some other rocks, 1,000,000 years will have substantial effects on the Calanques.
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| Enjoy this beauty while it lasts! It may erode(not in our lifetime) away long before other more impermeable rocks. The chemical process of this limestone with H2O makes it decay comparably quickly to many other sedimentary rocks. Tectonics may provide the other end of this cyclical process and build up new mountains through uplift. |
References:
-Allen, Casey. Class Lecture. Introduction to Physical Geography. University of Colorado Denver, Denver, CO. Aug.- Dec. 2012.
-Speer, David. "Crystal Cave: Karst Topography." 12/15/06. Web. 10/8/12. http://www.uwec.edu/jolhm/Cave2006/Karst.html
Images:
Images:
-Wikipedia
-Allen, Casey. Class Lecture. Introduction to Physical Geography. University of Colorado Denver, Denver, CO. Aug.- Dec. 2012.
-http://marseillez.free.fr/marseille_e.html
-depositphotos.com
-dennis avery climatologist chart http://globalwarming-factorfiction.com20090409powerline-graphs-how-about-some-background
-depositphotos.com
-dennis avery climatologist chart http://globalwarming-factorfiction.com20090409powerline-graphs-how-about-some-background
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