Tolminski Migovec Cave Exploration

SLOVENIA

Expedition 2005

The Migovec plateau is situated in Northern Slovenia near the Italian and Austrian borders. Imperial College Cave Club intends to continue exploration and mapping of the known entrances on the plateau and search for new, currently undiscovered caves.

Previous Work

There are three large caves near the Migovec plateau. The largest is the Migovec System [2000 PDF Survey], explored between 1994 and 2000 jointly by JSPDT and ICCC, which comprises 3 entrances, 970 m of depth and 11 km of length. The cave is characterised by big pitches and a number of smallish streamways connected by large fossil levels on an East West line. A conclusive dye trace has never been achieved from the Migovec System, but it is thought to drain into the Tolminka River.

Gardener's World (Vrtnarija) [Survey] was discovered in 2001 and exploration is ongoing. The cave has been pushed to 802 m in depth and 4600 metres length. The cave is characterised by a very vertical descent to -550 m where the first of two fossil levels is met before the final big pitch leads to a long stretch of passage that trends Northwards. Again we see a number of smallish streamways connected by this fossil level. However, the Northerly direction has enormous potential as it leads beneath Mount Kuk, which marks the watershed between the Adriatic and the Black Sea. A very interesting possibility is the connection of the two watersheds leading to a large, deep and significant system.

The third major cave near Migovec is Primadoni. This cave has been pushed mainly by the local cave club, JSPDT, to a depth of -454 m. They haven't yet found the fossil levels that have been seen in the other caves, but the exploration is ongoing.

Objectives

We have two aims for the expedition - the consolidation of some leads left in Gardener's World after last year's expedition and the pushing of new entrances.

There are at least four leads left in Gardener's World which should be investigated: the smallish streamway on Zimmer disappears into a rift which has not been examined; at the top of Big Rock Candy Mountain a window was reported by members of previous expeditions, and some strong and surprising air currents have also been reported in this area; there is an open passage near Red Cow Roundabout; and it should be possible to climb/bolt above Colorado Sump to find a bypass. We intend to establish a small camp in the same location as in 2003 at the entrance to Friendship Gallery.

We also intend to do a significant amount of surface work. The immediate area of the Migovec Plateau is well worked, but the area to the East and the North are almost untouched. Mount Kuk, to the North of the Migovec Plateau, lies above the far end of Gardener's World and has seen very little exploration. The peak itself is 200 m above the entrances to the Migovec System and 300 m above the entrance to Gardener's World. The area beyond Mount Kuk is virtually untouched by cavers.

The valley to the East of Migovec, towards Skrbina, has been partially investigated, and further work is planned this year. A tight, draughting slot, "Little Storm Cave", was widened until it was passable last year. Rocks were heard to fall for several seconds, but it was not descended due to time constraints. A strong freezing draught could be felt from nearby shakeholes, indicating good cave potential.

Also, a team widened a rift high on the Eastern flank of the plateau, above the entrances to the Migovec System. The rift dropped into a series of chambers, and another tight section which was widened until it was passable. The lead was not pursued, again due to time constraints. Additional Information

Transport and logistics

Most of the expedition's equipment will be transported by minibus along with a few of the expedition members. The other expedition members will travel by air, train and bus to Tolmin before ascending the plateau. We expect to transport approximately half a tonne of equipment by foot from our base at Tolminski Ravne, up ~ 1 km vertical and across 5 km horizontal to the summit of Migovec in the first few days of the expedition.

We have permission to camp on the plateau which has been arranged by the local cavers, with whom we have a strong relationship.

Specialist Equipment and Techniques

All vertical drops in the caves will be rigged for descent and re-ascent using single rope technique (SRT). Ropes are left rigged on the pitches: cavers abseil down and prussik back up, using special equipment. This is the safest and most efficient method for tackling vertical caves.

All cavers have been fully trained in SRT. Most expedition members are trained in safe rigging of pitches. The expedition includes many strong and experienced cavers, including some cavers of world-class expertise. Several expedition members have cave rescue and advanced first aid training.

All cavers will be equipped with standard caving equipment: warm undersuit, protective oversuit, SRT equipment, helmet, light and boots. Communal caving gear, such as ropes, will be bought by the expedition.

We meticulously map the caves using tape measure, compass and clinometer. This is a process that takes many hours of work at temperatures approaching freezing, often in confined areas. However, we are not just dedicated to the exploration of undiscovered caves, but also the reporting of those discoveries.

The survey data is then entered into a computer and three dimensional maps of the cave are generated using a cave surveying software package known as survex. We aim to measure all our surveys to less than 20 cm accuracy per leg. When more than one entrance is discovered, we can form a closed loop that allows us to estimate the error on the survey.

Chris Rogers & Jarvist Frost