Friday 3 October 2014

Return to Haweswater and Mardale: what's it like on the bottom of a reservoir?

We were tempted back because the TV had said that the village had reappeared. Compare these photographs to those I posted in August and you'll see that the water has only fallen another couple of metres. It will take a fall of up to 10m more to see the village. So we walked down the lane.

Notice that this stream is still in its old stream bed. It has had a channel built under the wall and it still goes under the bridge on the lane. This shows that conditions must be quite sedate at the bottom of the reservoir. There can be no strong currents because surely they would obliterate features like this. There was a reasonable layer of mud but deposition was not too bad considering that it has had 80 years to build up. So I've learned something about hydrodynamics.

The church and the main bridge in the centre of Mardale are still underwater to the left of the islands. More walls have appeared on the near shore since August. I now think that the island is probably a roche moutonee. A "sheep rock" is formed when a glacier flows over harder rock. Here the glacier would have gone left to right. That smoothed the left hand side but pulled chunks out of the right hand side leaving it craggy.