How is a Glacier Formed?

Aim: To be able to understand the way a glacier is formed .

First watch this video, if nothing it is a simplistic version of how a glacier is formed.

Student Made Glacier Video 

• A glacier is formed in an area where the climate never rises enough to melt ice/snow.

• Snow initially falls as flakes which trap air, melting as they come into contact with the warmer surface temperatures.

• When the air temperatures drop, the melted snow refreezes turning into a more compact form known as FIRN or NEVE.

• Meltwater seeps into the gaps within the snow, freezing and compacting the mass further.

• As more snow falls, air is progressively squeezed out of the lower snow by the weight of the upper layers.

• When the accumulation reaches 150 feet the weight  after approx 20-40 years and pressure ensures the snow is crystalised into solid ice.

• During this time the ice may take a bluish olour, indicating that most of the air has been expelled.

• As more snow accumulates and the ice mass grows thicker it becomes too large to sit still and gravity pulls the ice downhill.

• This is the ice that begins to flow downhill as a glacier.
  

Dr Iain Stewart provides a video version of this process.

How Glaciers Are Formed - Iain Stewart 

IN PRACTICE: The video above is the perfect idea for group work for students. By combining IT and the fun of music and animation, videos like this one can prove as a successful self learning activity for students.

REFERENCES:

Redfern, D & Skinner, M (2005) Advanced Geography. 2nd Edition. Philip Allan Updates, Oxfordshire.

Stewart, I (2007) Video clip “How Form” from Episode “Ice” from Series “Earth: The Power of the Planet”