02 December 2005

Winter visit to Dersios

On Sunday 27 November, Nikos Mitsakis and Komninos Boutaras went up to Palaiochora for a day trip to have a look at the sinkhole in the winter and de-rig after my accident. The roaring sound of the river flowing into the sinkhole and draining most of the plateau could be heard from the road.

The water goes down to the junction with the second sidebranch and then (as predicted by Komninos during the summer) it turns left into the sidebranch where it ends up at the sump in a mess of frothing and noise.

Some of the water carries on towards the first sump, but disappears before the little transervse section, and then reappears after the "screw". From there it makes its way to the first sump.

At the first sump, there was a clear froth line at the level to which the sump usually fills, but the water in the sump was very low, just a little higher than during the summer. This means that to date this winter the hose trick is working, despite the sump having filled to the brim since we left the system in place.

I'm just trying to picture some scenes in my mind's eye - like how the water would flow through the narrow passage in the sidebranch, how the waterfall would shoot water out of it at the end of the passage, and what the junction at -151m between the sidebranch and the main route would look in full flow… but we will probably never have a chance to see any of this.

After the mission, we now have a much clearer picture of which areas are prone to flooding in case of sudden rainfall, but we also have a better picture of the hydrological situation in the cave.

PS - what do people think? Is it coincidence that the bats prefer to nest in the parts of the sinkhole in which there is no running water - ie in the chamber before the traverse over tha small lake and in the screw?

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