GLACIERS

Here goes my first blog! 

I'm going to look at Glaciers, a subject that I have never covered throughout my time studying Geography.

So firstly the all important question . . . What is a Glacier?

Glaciers are made up of fallen snow which has over passed the melting of evaporation period this then becomes compressed to create a large area of thickened ice masses (the size of a glacier can vary dramatically, some as large as a football field and some being hundreads of kilometers wide), the process takes place over a number of years. The ice masses have the ability to move and currently glaciers make up almost 10% of the worlds surface, most commonly being located in the Polar regions. 

The Global location Glacier Regions

Location of Glaciers

Looking at the map above it is quite clear as to why glaciers would be located within the polar regions with their cold temperatures and abundance of water, however the location of glaciers in Chile and parts of Africa may be a surprise to some people. In these areas there are mountain summits such as Kilimanjaro where the higher up the mountain the colder the temperature which leads to the creating of glaciers. The further down the mountain you move, as temperatures rise the process of albation takes place. This is the process by which ice is lost from a glacial surface through the processes of melting, sublimation or the calving of 

icebergs. 

How Glaciers effect Land

The sheer size and weight of glaciers suggests that they will impact the landscape in some way. Glaciers are also responsible for carrying broken rock far from its area of origin, something scientists have witnessed globally. 

Glacial Erosion

Glacieated Vallys : This is where entire mountain sides are removed by glaciers often leaving steep sheer cliffs. An example is Yosemite National Park in the USA where glaciers left deep valleys. 

Fjords: "are long, narrow coastal valleys that were originally carved out by glaciers. Steep sides and rounded bottoms give them a trough-like appearance. Because of glacial erosion on the below sea level land surface, when glaciers finally disappear, sea water covers the valley floor". This type of glacial erosion is common in Norway. 

Glaciers and Climate Change

Glaciers are a key tool in understanding how the atmosphere has changed over thousands of years, particularly as the age of the ice caps can vary so much. Scientists have  taken samples from a number of different glaciers globally and have studied them to gain information about the past climate of our world. The ice caps contain important information such as trapped air bubbles which can tell scientists about different types vegetation and atmospheric conditions. Using this data scientists can map the expected temperature changes to our atmopshere based on the previous Ice Ages, however there is a problem  . . . .  .

In recent times glaciers around the world have been retreating at an alarming rate, this is mainly due to events such as the Industrial Revolution and the use of fuel such as petroleum and coal which attribute to the increase in carbon dioxide in the atmosphere and also green house gases. The glacier retreat has been so severe in some cases that glaciers have disappeared altogether. 

Links: 

http://nsidc.org/cryosphere/glaciers/questions/what.html 

http://nsidc.org/cryosphere/glaciers/questions/climate.html 

http://nsidc.org/cryosphere/glaciers/questions/land.html 

http://magma.nationalgeographic.com/ngexplorer/0501/quickflicks/ 

http://ga.water.usgs.gov/edu/earthglacier.html

As a teaching aid this video on the creation of Glaciers could be used: http://www.youtube.com/watch?v=tM3x6_vb8_s