Breakdown...Beware!

 

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.

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.






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.







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.



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.


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.

-Fett, Bob. World Wind Regimes-Mediterranian Mistral Tutorial. NRL Monterey, Marine Meteorology Division. Dec. 2002.  http://www.nrlmry.navy.mil/sat_training/world_wind_regimes/mistral/index.html

-Speer, David. "Crystal Cave: Karst Topography." 12/15/06. Web. 10/8/12.   http://www.uwec.edu/jolhm/Cave2006/Karst.html

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

What is going on above ground?

Calenques National Park is a corridor for different winds.  The "Mistral Winds" that come in from the Northwest can blow in excess of 90 kilometers per hour and play a heavy role in the climate of Marseille’s entire region, Provence. This wind is commonly seen in winter and spring, but it does make appearances throughout the year anytime that conditions are right. It is caused by high pressure cells that have an anti-cyclonic pattern in the Atlantic Ocean west of France and low pressure cells with cyclonic patterns in the North Sea redirecting the jet stream coming across the Atlantic from the west. The "Mistral Winds" along with the "Tramontane Winds", also coming from the North at a similar time of year, both primarily bring dry conditions because of the dry continental air masses moved. Since much of the air flowing south is following the contour of the mountains and staying low it can often be considered stable.


This picture show the patterns of "Mistral
Winds."The High Pressure Cell is
anti-cyclonic as opposed to the cylonic
Low Pressure Cell. Both working together
to push the winds southeast.

This photo shows the air following the contour of the Mountains as
it crosses over southern France. This is the Tramontane winds coming
from the north and moving south.  They are carrying more moisture
further south than normal.

Since air always moves from high pressure to low pressure there is another interesting phenomenon that leads to the climate at the Calenques.  This is the diurnal flow. 

In the daytime breezes flow inland and at night

breezes flow out to sea.

This park is right next to the sea and at the base of the mountains causing heavy changes in pressure and temperature throughout the day.  The land heats faster and cools faster than the sea so this creates a daily pattern of changes in direction of breezes. With this change in heat the air will flow from the colder sea to warmer land in the day rising when it heats and falling as it cools and vice versa at night.  The motion of air coming off the Mediterranean is what gives Provence more accumulated annual rainfall per year than many inland regions of France.

Water heats slower and retains its heat longer because

 it is translucent and constantly mixing colder water

 with warmer water while land is opaque and has no

mixing as show in this picture.

References:
Allen, Casey. Class Lecture. Introduction to Physical Geography. University of Colorado Denver, Denver, CO. Aug.- Dec. 2012.
Fett, Bob. World Wind Regimes-Mediterranian Mistral Tutorial. NRL Monterey, Marine Meteorology Division. Dec. 2002. http://www.nrlmry.navy.mil/sat_training/world_wind_regimes/mistral/index.html
Images:
Wikipedia
Allen, Casey. Class Lecture. Introduction to Physical Geography. University of Colorado Denver, Denver, CO. Aug.- Dec. 2012.

Weathering




Caves such as this one can be found throughout the calenques.
This is formed by chemical dissolution.

In the top left corner of this picture there is a debris slide
showing slope and gravity working into physical weathering.
Colluvium in this slide is creating friction on the way down.
The people and water are also creating physical weathering.
Trees growing from the fractures in the rock are expanding
the cracks as they grow further breaking the formation.

There are several processes of weathering that play into the way the landforms in Calanque National Park look. There are physical processes of weathering as well as chemical processes of weathering working at the same time. Wind, water, slope, and gravity all have their roles in the physical decay of this sedimentary landscape. Fluvial forces, such as rivers and streams, have a heavy role in not only the physical weathering, but also lead to the chemical process of decay. The reaction of water with the limestone which makes up most of the landscape creates a carbonic acid.  This acid starts a process of dissolution of the rock. This chemical breakdown can cause very interesting formations such as monoliths, caves and chasms which add to the awesome visual that this region provides. The limestone formations with very few other types of rocks, soils or other biological matter are called a Karst topography.  This name comes from similar formations found in Eastern Europe.  Streams coming through this Karst landscape over millions of years have not only provided the water which acts as a catalyst to the chemical process, but also carry out any alluvium that was created by other physical processes.  Where these streams are eating their way through the landscape there are inlets coming off of the Mediterranean Sea.  These inlets are called Calanques and they can be seen in many places along the coast.  In the Calanque National Park there is a large distribution of these inlets in a small area thanks to our weathering processes.

These two photos give another view of the forms created by chemical and mechanical weathering








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

 Photos:
http://marseillez.free.fr/marseille_e.html
depositphotos.com

Limestone Cliffs

Toothpaste



Cement Mix

The beauty of Calenque National Park primarily comes from the contrast of the Mediterranean Sea and the white cliffs. These cliffs are made up of limestone. The limestone itself is a sedimentary rock made up of small fragments of biological matter such as coral and shell particles. These fragments are formed in large part of the chemical compound calcium carbonate(CaCO₃) which is often represented by the minerals calcite and aragonite. Similar minerals can be found in everyday items such as cement, pharmaceuticals and toothpaste. So the limestone was made up of organics collected on an ocean bed over long periods of time and then compacted or cemented together to make a sedimentary rock, and they came out stunning.

Pharmeuticals

             Much of the material in the area other than the limestone has been eroded away to leave the awesome cliffs with inlets throughout which are known as the calenques.  The formation of the calenques can be explained in a bit more detail later when we discuss weathering and mass wasting. However, it is worth noting now that limestone is a rock that can dissolve fairly easily when in contact with waters and acids.

The limestone from this region has been quarried for many years.  One notable iconic use of the rock from this region is the base for the Statue of Liberty.

The limestone in the national park is found on nearly 15,000 acres of land including above the sea and below the sea.  There are 24 different main inlets throughout the region as well as many smaller ones and some other calenque formations which are inland just a bit.

 

References:

 

Marseille Tourist Office.  9/12/12.

http://www.marseille-provence.info/places/sights-and-attractions/237-the-calanques.html

Ritter, Michael E. The Physical Environment: an Introduction to Physical Geography.             

                9/15/12. http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/title_page.html

Virtual Museum of Minerals and Molecules

http://virtual-museum.soils.wisc.edu/carbonates.html

Dal Negro, A., and L. Ungaretti. 1971. Refinement of the crystal structure of aragonite. American Mineralogist.

                 56:768-772.

Graf, D. L. 1961. Crystallographic tables for the rhombohedral carbonates. American Mineralogist.                                  46:1283-1316

 

depositphotos.com

 

Introductory Post

Hi, my name is Ben Lunders. I am in my final semester at UCD finishing a degree in Political Science and History. I have always loved to travel and see new places. The thrill of seeing new settings with different cultures, rich history and unique food cannot be equaled.

One of the most beautiful and odd natural settings that I have continued to wonder about is Calanques National Park on the edge of the city of Marseille in southern France. I went there in 2007, and hope to go back some day before I die. These house fishing villages, a variety of aquatic life and WWII bunkers amongst other things.  I look forward to getting a better understanding from my physical geography class on the formation of this landscape which seems to be deteriorating as you look at it. These white and gray cliffs sprout out of the ocean creating wonderful coves, caves and other places to hide. Go visit Marseille!