Monday, 20 December 2010

Ice and mud

9-20 hrs: Ice forms over the mud at low tide - some mixed with snow. We wondered what happens when the tide comes in - does the ice float or does the water run in over the top. As the rising tide was during darkness this week - I did not observe it. But I do offer the picture to show what seems to happen.

The tide comes in and lifts some of the ice and breaks it up. This is carried upstream and  downstream on the tide. When there is no obstacle - it floats off downstream or melts. When, as in the picture, there is something  in the way, the ice stays put in large slabs. Some ice seems to stick to the bottom and get covered in mud after a couple of tides. The process leaves a lot of mud for the birds and some ice for us to look at.

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