07 September 2005

Report on the expedition of 24 and 25 July 2005:

On Saturday the heat got to us a bit so we went for a swim first and then for a look-around in the area. Our look-around had some promising results and brought to light a number of places well worth looking into in the future.

That evening, the expedition cook ate and slept in a cheesevault near the sinkhole, something which allowed us to sleep a little beyond dawn as we weren't woken up by the heat.

The sump in the second sidebranch had emptied and was surveyed by Komninos and myself, allowing us to close a loop back at the entrance lake. The loop is about 250m long and we got a 5% declination in doing so. This will no doubt change when we confirm the survey data next week.

In the end it was one reading on the clino which was made wrong. When this was corrected the loop closure gives an error of less than 2% and these new figures were used in all surveys after 30 July.

The first sidebranch is most probably the old river bed - it has the same direction as the sink-hole's main chambers but it ends in waterlogged sections at about -40m. We started an effort to drain this sump also, using the 120m of one inch hose in an effort to allow access for non divers to the narrow fissure which Nikos had seen at the end of the sump the week before.

The first sump was passed with difficulty as it had filled again with the waters from the sumps above it, but the team of Nikos-Giota-Panos managed to make some repairs to the 1 1/4 inch hose and restart the draining. For this reason, it was not possible to dive the second sump.

The expedition was manned by: Nikos Mitsakis, Komninos Boutaras, Yiota Kafetzi, Stelios Zacharias and Panos Papasotiriou.

Results of the survey conducted on 25 July 2005:
The results are presented as projected elevations, using the vtopo programme (link in sidebar to the right).

The entrance is at point Α
The first sidebranch is points Β-Γ
The second sidebranch is points Δ-Ε
The union of the two can be seen in blue
Point Ζ (sump) remains underwater as at 25 July 2005, but efforts are being made to drain this sump also and open new routes.

No comments: