Monday, October 09, 2006

Frost Shattering

Last week we were looking at FROST SHATTERING as one of the processes that are at work on Svalbard. This is shown below in a series of pictures which dramatically show the sequence which shatters rocks into smaller pieces.The pictures are used with the permission of Chris Durbin, who appears in the first picture above. He used to be a Geography adviser, and also worked at the BBC on the Bitesize resource and some Geography programmes which you've probably seen, and was one of the people who launched the very successful SLN resource, which is used by a large number of Geography teachers, and who now works in Hong Kong. Chris e-mailed me earlier in the week from Hanoi - can you find out where this is ? - to give me permission to use the pictures here. They show a sequence by which a rock has been slowly broken apart by water freezing and then thawing in the cracks. This produces the rocky landscape which can be seen in the later images.

Notice how the bits that break up just fall to the ground. This means that the process is called WEATHERING. If the bits of rock were removed by water or wind or ice, this would then become EROSION, which involves movement.
These loose rocks will pile up to form what is called a SCREE or TALUS.

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