So we went to Dersios at the weekend with three of the new guys. Dersios is a sinkhole in Arcadia, about 700m up and quite a way from the sea. It was explored a while back to -80 odd meters by a French team together with ESE - the Hellenic Speleological Society. Since 2003, teams from SELAS Caving Club, Greece has been exploring the cave, doubling the depth and more than tripling the surveyed length. It has been surveyed to -161m so far, but has a lot of unsurveyed (and unexplored) passages. This year we are going to try and push the exploration a little further through a combination of diving and emptying of sumps.
We arrived after much faffing at well after one pm, set up our tents and got ready to go. We were in the cave just before four - so there was another faff involved which I am not sure I remember although some of it involved being barked at by dogs while trying to talk to an old man in a shack who claimed to know of a pothole somewhere in the hills. This would be especially pleasing if it exists. I have had suspicions about the existence of something in the hills above the cave for a while, based on plotting the track of the cave under a 3D representation of the hills above. This is something for a future visit, though.
Splitting into two teams, the first went for the first sump, now empty, thanks to the efforts made last month, while the second went for the sump in the second side-branch.
Last month's efforts (!) - Photos by Maggie
Once there, we prepared the sump for emptying, gathering in last months green hoses - repairing the join between the stretch of 20m and 50m hose with a piece of inner tube, some flanges (?) and a swiss army knife. Then while Panos went into the water up to his thighs, Martin, Michael and I helped bring the hose down to the sump and pass it to Panos who sunk it in such a way as to empty it of air as it went in. Once completely submerged we capped the end of the hose with a piece of inner tube, preferring it to the heroic rubber glove used in June. The use of a non solid cap for the hose had the unexpected advantage that it allowed the caver walking the hose lower to know exactly when the hose exit was at the height of the sump surface - the glove or inner tube would be sucked into the hose when the hose end was above the sump surface and would expand out of the hose when below the sump surface.
The glove! - Photo by Maggie
The inner tube expanded to resemble a dark aubergine, the shiny black curved surface taking our attention from the pressure which was to build up, break out and cover us in bits of rubber and plenty of sump water moments later.
Success - the flow had started! It was about six or seven pm.
It was somewhere around this time that we first noticed the increased number of mice in the cave. For me at least it started as one of those periphery of vision experiences where objects jump around on the edge of my field of view somewhere between where the torch no longer lights and where the sharp image created by my spectacles merges with the blurriness. This was slightly different. The blurriness and jumping around was about 40mm long and moving independently of where I moved my head. To find a mouse down where we saw this one did not surprise me. The poor thing had obviously got lost and had somehow found its way into the cave and down the main path some 90m into the cave and 30m below ground. It scampered off and we carried on with the day's tasks. Martin and Michael left Panos and myself to finish off the plumbing and headed off towards the first sump. Panos and I brought the black hose from the original 2003 emptying of the first sump up to join it to the flow from the second branch's sump. The idea was that if we could increase the height difference, the outflowing water would have greater pressure and therefore increased speed on its way out. As it was we had a difference in height of about 5-10m, but the addition of the black hose (50m length) gave an extra -13m worth of pressure to the flow.
Although we had come prepared, we did not use the plastic hose joiners, but taking some of the already burst innertube we rigged up a join with the flanges between the two pipes. Once the water started to flow we could feel the negative pressure on the join - a sign that the suction was increased. Unfortunately we hadn't waited long enough for Martin and Michael to move away and Michael got a hose load of sump water poured on him while he was on-rope. It's a learning process all around…
Moving on, and through all the parts that had caused me trouble in the past - through the bits where you have to brace yourself against the walls with hands and knees and back and arse to avoid the water below, and on to the first sump, now empty and not too tough to negotiate a way through, and on to the new passages, which saw light for the first time in 2003. The rigging team of Komninos, Giannis, Kostas and Margarita were a way ahead of us now and we were finding everything ready in front of us down to the junction at -151m where from the height above the junction we could see the satisfying glow of the acetylene below us. I stayed there and took in some calories I the form of cashews and almonds, while Maggie took the Murphys to the bottom and back and then we all started the climb to the exit, spotting mice all the way home.
We were all out at about 0400 hrs and made pasta before going to sleep. Martin had brought a travel fridge with beers, ice and tsipouro, so we managed nicely to unwind before watching the first little hints of daybreak come to remind us that the sun wouldn't allow us to get much sleep that night. True enough, the sun had woken us all by nine, so we de-rigged the entrance and got ready for the drive down and the beach.
Now, these mice...
They come in two different types. Small and Large. The small ones are all a very light grey colour and about 40mm long from snout to bum. The larger ones are dark grey with a white belly and about 100mm long from snout to bum. The larger ones were seen to rear up onto the hind legs (not unlike a kangaroo) and jump from this position from rock to rock. Small ones just scurried.
Questions:
1. Are these one or two different species? - if one, is it kiddie mouse time, hence the different sizes and colours?
2. If these are two species, how does that work out? The cave is a very difficult niche for one species of mouse to live in, let alone two. If they were competing for the same food source, they would not be two. If they are not competing how much is there that a mouse can eat inside the cave anyway?
3. How the hell do they get around down there in the pitch black darkness?
4. The ones spotted below the first sump - how did they get there? Was it:
a) after Nikos opened the route in 2003?
b) after Nikos opened the route in June?
c) through small passages they can fit into that we cannot fit into?
d) they got swept into the cave in the great cataclysm of 1910 and have been living down there happily since?
e) other
Wouldn't it be great to take blood from a whole bunch of them and see which mice are related to which and track changes in their mtDNA and compare it to mice living outside and stuff?
That is all for some other time though.
No comments:
Post a Comment