As the wind gradually died, it was time for ISIS to go back in the water. Now looking at the western most branch of the Whittard Canyon, starting at the deepest part (around 2900m) it became apparent very quickly, that things were very different here.
We had seen mostly in the previous dives, long flat plains of sediment, gently rippling and dotted with occasional beasties. This time we found ourselves face to face with a massive boulder COVERED with anemones...! As the dive progressed, we began with big boulders and craters, and moved through more hummocky terrain, into much flatter regions with areas of the underlying chalky rock exposed.
The main reason we think this happens, is because the bathymetry (like topography the brown contours on an OS map but underwater) shows us that the western branch becomes very steep very quickly to the Northwest of the main canyon. This steepness may increase the speed and because of the speed, the size, of the sediment being transported down the canyon branch. Once the canyon begins to flatten out, the flows loose energy very quickly, and large blocks are the first to be deposited.
This is all very interesting for the geologists, who are mapping the different rock/sediment types we see through the canyon, in the hope of understanding the system that little bit better.
Above: Anemones galore!
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