Tuesday, November 13, 2012

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.

Wednesday, October 10, 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


Sunday, September 16, 2012

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

Wednesday, August 29, 2012

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!