In a search for the route to 2000 meters depth: The Deepest in the World in the Arabika Massif, Western by Alexander Klimchouk and Yury Kasjan--Ukranian Speleological Association Photographs by Oleg Klimchouk, Denis Provalov, Yury Kasjan, Vladimir Kisseljov, and Alexander Klimchouk In January 2001, the expedition of the Ukrainian Speleological Association explored Krubera (Voronja) cave in Arabika to a record-breaking depth of 1710m. For the first time in the history of , the world's deepest cave has been explored outside of Central/Western Europe. It stands alone as the most remarkable achievement in super-deep exploration of the recent decades, the largest single breakthrough in depth since 1975. Overcoming of the previous depth record of Lamprechtsofen-Vogelschacht in Austria by 80m is particularly impres- sive compared to the three previous records, each of which raised the bar no more than 20 meters (to - 1602m in 1989, -1610m in 1998, -1632m in 1998). This article briefly describes speleological potential of the Arabika massif and history of its exploration and gives some details of the Krubera cave and the recent record-breaking exploration. tems (Klimchouk, 1990). On the north- central part is shown in beige tint in west, northeast, and east, Arabika is bor- Figure 1 and indicates the area above the ARABIKA MASSIF: SPELEOLOGICAL, dered by the deeply incised canyons of tree line at approximately 1800-1900m. GEOLOGICAL, AND HYDROLOGICAL the Sandripsh, Gega and rivers. The highest peak (the Peak of FEATURES The latter separates Arabika from the Speleologists) rises to an altitude of adjacent Bzybsky Massif, another area of 2705m. Some low-altitude ridges covered The Arabika Massif is one of the major speleological significance in the with forest stretch from the central part largest massifs of the Western with Snezhnaja towards the . Caucasus. It is located in Abkhasia, the Mezhonogo (-1370m), Pantjukhina (- Among several hundred known republic that officially belongs to 1508m) caves and many other consider- in the Arabika massif, some deep caves although claims itself as an independent able caves. were explored during the 1980s (indicat- state. The latter is the matter of still unre- Glacial trough valleys formed during ed by red dots in the Figure 1), including solved political contradictions between the late Pleistocene glaciations are the Iljukhina system (-1240m), Arabikskaja Abkhasia and Georgia that caused the main features of the central part of the system (Kujbyshevskaja-Genrikhova major conflict in 1993-1994. Arabika massif (Klimchouk, 1984), with Bezdna; - iliUm), Dzou Cave (-1080m), The massif has strongly pronounced ridges and peaks in-between them. The Moskovskaja Cave (-970m), Sarma Cave glaciokarstic surfaces at elevations rang- ing between 1900 to 2500m, and is com- posed of Lower and Upper Jurassic . In the central part of Arabika the formations of Cretaceous age remained only in some ridges and peaks, as well as in patches within trough val- leys. The core part of the massif is com- posed of Upper Jurassic strata that dip continuously to the Black Sea shore and submerge below the modern sea level (Figure 1, profile). Geologically, Arabika corresponds to the large of the sub- Caucasian (NW-SE) direction with the gentle dipping south-western mega- flank (complicated by several low-order folds of the same direction) and steeply dipping north-eastern flank. The massif is severely tectonised, with the -block structure strongly controlling both cave development and groundwater flow sys- Caves.com Page 16 (-700m) and Cherepash'ja Cave (-650m). canyon, although it apparently drains a Kiknadze made some additional investiga- The deepest cave, Krubera, is located in large area in the southeast of the massif tions in Arabika, analysed available data the Ortobalagan trough valley, some (the hypothetical Eastern circulation on geology and hydrogeology of the mas- 300m to the southeast of, and 60m above system, number 3 on Figure 1). This out- sif, and published its monographic the Kujbyshevskaja Cave, the main line remains rough, and catchment areas description (Kiknadze, 1972). Although his entrance to the Arabikskaja system of some other considerable springs (in ideas on the structure of karst circulation (Figures 2 and 3). Although Krubera Cave particular those located in town) systems were not confirmed by later dye is not connected directly to the are not yet clarified. Increase of the num- tracing experiments, this book was an Arabikskaja system, it most probably ber of deep caves with shaft flows and important summary of karst and caves of forms a single hydrologic system with the further tracing experiments will clarify the Arabika. latter. picture in the future. During the late 60s and 70s the caving Figure 2 depicts quite strong tectonic con- clubs of Moscow, Crimea and Krasnojarsk trol of cave development in the plan view. HISTORY OF KARST STUDIES AND made several expeditions to the massif. Some segments of the major caves CAVE Major discoveries were the Genrikhova stretch along faults, other parts twist with- EXPLORATION IN ARABIKA Bezdna cave in the Ortobalagan trough in major tectonic blocks and reflect back Of the rather rich history of karst and valley (the 120m deep entrance shaft inside blocks when reaching a fault. The speleological investigations in Arabika we ended with a squeeze) and the main branch of the Krubera Cave slew shall mention below only some names, Jubilejnaja, Karrovaja, and Akhtiarskaja many times and goes steeply in depth by events and circumstances which seem to caves in the northern part, explored vertical pits separated by short meanders. be the most important in the context of the respectively to -260, -200 and The cave remains within a small tectonic modern state- of-the-art in cave explo- -160m. With only six 100m+ deep caves, block and does not extend beyond the ration. two 200m+ and no 300m+ deep caves limits of the trough valley. In the beginning of the 20th century, explored before the late 70s, Arabika had Major karst springs with individual Arabika was visited by famous French acquired somewhat contradictory reputa- average discharges of 1 to 4 m are locat- speleologist Edward Alfred Martel, who tion among cavers ("Good potential but no ed at altitudes ranging from 1m (Reproa published several works about the massif Spring) to 540m (Gegsky Vodopad) above (i.e. Martel, 1909). In 1909-1910 well- the sea. Submarine springs are also known Russian karstologist Alexander known here, emerging from the Black Sea Kruber, a founder of karst science in floor at depths of 20 to 40m and probably , performed some field studies in below. Some boreholes located along the Arabika. He published his observations in Black Sea shore yield karstic groundwater a series of specific papers (Kruber, 1911, from depths of 40 to 280m below sea 1912a, 1912b) and in his major mono- level. An outline of the hydrogeological graphs. During the following 50 years no structure of the massif and its true speleo- special studies of karst and caves of the logical potential were revealed in the massif had been done, although the karst 1980s, when spectacular progress was of Arabika was referred to in many works made in deep cave explorations and two dealing with regional geology and hydro- large-scale dye tracing tests (in 1984 and geology. 1985) proved connections between the In the beginning of the 1960s, specific major caves and springs (Klimchouk, speleological investigations were started 1990; see Figure 1). Tracers injected in by Georgian researchers (Maruashvili, the Kujbyshevskaja and lljukhina caves Tintilozov and Changashvili, 1961, 1962; were detected in Kholodnaja Rechka Maruashvili and Tintilozov, 1963). They (1.5m3/s;50m a.s.l.) and Reproa (2.5m3/s; recognised an important role of the 1m a.s.l..) springs on the seashore. The Quaternary glaciations in karst develop- tracer from Kujbyshevskaja has also been ment in Arabika and began to explore detected in a borehole that yields ground- caves in the high altitude part of the mas- water from the depth of 40m below sea sif. Despite obvious limitations imposed by deep caves"). Discouragement about level, located between these two springs. poor equipment and technique and the Arabika was strengthening by contrast This gave a reason to distinguish the general "infant" state of Soviet speleology with the adjacent Bzybsky massif where large Central karst circulation system then, Georgian researchers explored sev- many 100 to 300m deep caves and sev- (number 1 on Figure 1), the deepest in eral vertical caves (up to -250m) and eral 500m+ caves were under active the world at that time with the vertical pointed out the considerable depth poten- exploration, including Snezhnaja Cave amplitude being over 2300m. It corre- tial of the massif. In particular, they made with its -1380m. By the late 70s, Arabika sponds to the most of the southeastern a first exploration of an open-air 60m shaft had been virtually abandoned by cavers. flank of the major Arabika anticline. The in the Ortobalagan trough valley and In 1980 the Kiev Speleological club led by tracer injected in the Moskovskaja Cave named it after A.Kruber, the cave that in Alexander Klimchouk chose Arabika as (-970m) have been detected at the the very beginning of the 21st century the main focus for its exploration efforts Gegsky Vodopad spring, indicating the became the deepest in the world. Forty and implemented a strategy of thorough presence of the karst circulation system years ago, however, Georgian speleolo- and systematic search on an area-by-area comprising the northeastern flank of the gists were stopped by an impassable basis. This appeared to be particularly Arabika anticline (the Northern system, squeeze in a meandering passage that successful in this formerly glaciated karst number 2 on Figure 1). No connections stretched from the bottom of the entrance massif, in contrast to the previous "quick- were revealed with yet another major shaft. search" practice, because of glacial debris spring, Goluboje Ozero in the Bzyb River The Georgian researcher Tamaz blockage of most open-mouth shafts. In Caves.com Page 17 addition, a "no dead ends" concept was adopted that implied re-inspection of all known caves and systematically challeng- ing such common obstacles as boulder chokes and squeezes that previously blocked exploration. The Perovsky Speleological Club of Moscow, led by Vladimir Iljukhin, joined our exploration activity in Arabika in the same year. This approach quickly led to important discoveries. Kiev cavers concentrated their efforts in the Ortobalagan trough val- ley where, among other caves, they pushed Kujbyshevskaja Cave through a series of expeditions (-450m in 1981, - 700m in 1982, -900m in 1985, -1110m in 1986). The main obstacles in this cave were boulder chokes, penetration through just one of which (Ugrjum-Zaval at -700m) took three years of arduous work. Meantime, exploration progressed in the nearby Genrikhova Bezdna cave, eventu- ally connected to Kujbyshevskaja at - 965m in 1989. The resultant system was named Arabikskaja. In the Krubera Cave, which was supposed to connect the in pushing the Perovskaja Cave. The explored in the massif, including seven Arabikskaja system and increase its total cave was renamed after an outstanding exceeding 500m+ deep. depth by 60m, exploration progressed Soviet speleologist, Vladimir Iljukhin, was In 1984-1985 two large-scale dye tracing slowly because of critically tight meanders accidentally killed by a car after the 1992 experiments were conducted in Arabika, between pits that required some widening Arabika expedition. They reached the first in which three different tracers were used to get through. The cave was pushed to - sump at -950m in 1984 and spent huge to trace shaft flows in Kujbyshevskaja, 340m during 1982-1987 and then explo- efforts in the subsequent years negotiat- Iljukhina, and Moskovskaja caves. All ration was suspended. Two "windows" in ing through a series of three sumps and known springs and boreholes were moni- the P43 in the depth range of 220-250m, "dry" sections in-between them (including tored around the massif. These experi- indicated on the , remained a 230m deep section between the 2nd ments have proven hydrologic links from unexplored. During this period the cave and 3rd sumps). The forth sump, at - Kujbyshevskaja and Iljukhina caves with received its second name Voronja (Crow's 1240m, explored for about ilOm in length the major springs at the seashore over a cave) due to a number of crows which in 1987, remains the end of the system till direct lateral distance of 14- 20km and nested in the entrance shaft. Another now. In this extreme exploration one of vertical amplitude of over 2300m. cave in this valley, the Berchil'skaja Cave, the leading roles had been played by Obviously, the decade of the 1980s result- (located 150m higher than Krubera and another outstanding Soviet speleologist, ed in dramatic progress in speleological 210m higher that Kujbyshevskaja) was Vladimir Kisseljov. exploration in Arabika and in revealing its pushed by Kiev and Moldavian cavers Important discoveries made in Arabika by true depth potential (Klimchouk, 1990, down through a vertical boulder choke Kiev and Moscow cavers in the early 80s 1991). that extended almost continuously from attracted many caving clubs of the former The political and ethnical conflict in the bottom of the upper 60m deep shaft Soviet Union. Cavers from Leningrad, Abkhasia in 1992-1994 and instability and to the current end at -500m. Sverdlovsk, Krasnojarsk, Minsk, Kishinev, border problems, which continued Cavers of the Perovsky club, based main- Poltava, and also foreign cavers from throughout the subsequent years, sus- ly in the upstream part of the Central Belgium, Britain, Hungary, Italy and pended speleological explorations in trough valley, invested most of their efforts got involved in Arabika in various Arabika. Although some small groups of years. All explorations cavers occasionally visited the massif dur- during the 80s were ing this period, planning and realisation of closely co ordinated, large and serious expeditions was not by planning work feasible. Stabilization of the situation in ahead for each com- Abkhasia since 1997 has allowed us to ing year and assign- re-activate exploration efforts in Arabika. ing certain areas for involved groups. RECENT EXPLORATIONS Results were reported IN ARABIKA: on the regular Arabika BREAKTHROUGH IN KRUBERA CAVE conferences held in In 1998 the CAVEX team, consisting Kiev after each field mainly of Kiev and Moscow cavers, made season. By the end of a breakthrough in the Dzou Cave in the that decade, 36 caves northern part of Arabika, previously exceeding lOOm explored by French Villefontaine and deep had been Moscow Perovo Speleoclub teams

Caves.com Page 19 to -493m and after Vladimir Kisseljov -1215m. On the second stage the MTDE team to -750m in another part of the team, composed of six cavers from cave. The expeditions of 1998 and 1999 (Sergio Garsia Dils de la Vega, Vilafranca resulted in discovery of a laterally exten- Javier la Pera, Enrico Ogando Lastra, sive major river passage at the bottom Juan Alberto Martin Otero, Aifredo area and in pushing the cave to -1080m. Morena Rioxa, Ramos Ignacio de Rafael) In August 1999 the expedition of the and two cavers from France (Bernard Ukrainian Speleological Association (that Tourte and Olivie Ubiergo) joined Yury included cavers from Poltava, Kharkov, Kasjan and Denis Provalov to continue Uzhghorod and Dnepropefrovsk) led by exploration. They reached a depth of Yury Kasjan, re-started the work in the 1410m in a branch piece that seemed to Ortobalagan trough valley, in the lose airflow and ended with a squeeze. Arabikskaja system, and in Krubera. In When ascending after the very last trip to fact, the main target was to find a connec- the "bottom," Yury Kasjan found a "win- tion between the Krubera and dow" in the wall of a pit at -1340m, which Kujbyshevskaja caves that would promised to give a continuation. increase the total depth of the system by There are many aspects, some of which 60m. In Krubera, the team checked the lie beyond the scope of rational thinking, two "windows" in the walls of the P43 in which experienced cavers evaluate when the depth range of 220-250m, which assessing the prospects for further explo- remained unexplored since the 1980s, ration. In the fall of 2000 we clearly heard and found continuations in both. The "The Call of an Abyss" and felt a smell of lower window led to a new branch that the super depth. It was a mixture of mer Sverdlovsk caver, currently based in seemingly headed toward knowledge of general prospects of Pennsylvania, USA. Kujbyshevskaja, but eventually missed it Arabika, historical aspects, impetus of the On December 27 the expedition arrived in and ended up with a chamber (Non recent explorations, excellent team Sochi, the main city on the Russian side, Kujbyshevskaja) at -490m. The upper resources at our disposal and other, and crossed the Abkhasian border. On window opened to another branch that sometimes mysterious, feelings. Even the December28 a helicopter from , was explored to -750m during the 1999 coming turn of the centuries took its role. the Abkhasian capital, brought all mem- expedition. Alexey Zhdanovich from We could not wait until the next summer bers and expedition material to the Uzhghorod was instrumental in this break- and decided to organise the next expedi- Ortobalagan trough valley in Arabika. through and exploration. tion to the Krubera cave in the winter, a Work in the cave started on December29 The Ukr.S.A. expedition in 2000 ran in severe period in Arabika in terms of and in the same day the route was rigged two stages, both led by Yury Kasjan. access and conditions at the surface. to the first camp at -500m. Such a quick During the first stage (August), in which Among rational reasons for such decision start was possible due to preparations cavers from Poltava, Uzhghorod, Kiev, was a fear of sudden flooding at great made during previous expeditions and Kotel'va and Novaja Kakhovka participat- depths that could be expected in summer ropes conserved at the tops of main pits. ed, the main branch was explored and if the cave entered a hypothetical major By December 31 the route was rigged surveyed to river passage collector. down to -850m and many bags transport- A core of the winter expedition, ed to that point. Meantime, a special team organised under the banner of widened three squeezes in the upper sec- the Ukrainian Speleological tion of the cave (begun back in the 80s by Association, was composed Kiev cavers but still being hardly pass- from the members of CAVEX able) to a degree that allowed easy travel (Cave Exploration) Association, of many people and bags back and forth a strong group of dedicated though them. Kiev and Moscow cavers which On midnight of December 31 all the expe- have extensive experience of dition members gathered on the surface, deep caving expeditions in win- in a small cave near the camp, converted ter conditions. into a kitchen and dining room, to cele- brate the New Year and the beginning of THE WINTER EXPEDITION the new century and the millennium. 2000-2001 Everything and everyone were prepared The expedition began on to achieve the new world's depth record. December 25 and consisted of On January 1 the work in the cave contin- eleven members: Yury Kasjan ued. On the next day an advanced group (the leader), Julja set up the main camp at -1215m and now Timoshevskaja and Anatolij no one remained at the surface. All the Povjakalo (all from Poltava, expedition members carried out various ); Oleg Klimchouk, tasks of this assault. On January 3rd the Nikolai Solovjov, Sergey Zubkov advanced group reached the "window" at (Kiev, Ukraine); Vitalij Galas -1340m and began new exploration. The (Uzhghorod); Konstantin right to descend the first new pit in this Moukhin, Denis Provalov, expedition was granted to the youngest Dmitry Skljarenko (Moscow, member, Anatolij Povjakalo, who'd had his Russia) and lljua Zharkov, for- 18th birthday. By the end of the day a Caves.com Page 20 depth of about 1450m was reached. bers visited the bottom area for additional decided to leave all the equipment but The previous depth record of inspection, survey, and de rigging. The light camping stuff and force their way Lamprechtsofen-Vogelschacht was bro- big chamber was named the Chamber of down by foot. It was a risky venture due ken during the night of January 4-5 by the Soviet Speleologists, to appreciate the to the apparent avalanche hazard on the pair of Moukhin-Zharkov. They descended long and hard work of many generations way to the tree line, some 5km distance a few new pits, including impressive P49 of cave explorers of the former Soviet with a considerable traverse. The team, that went through almost black lime- Union leading to this remarkable achieve- split in two groups, was making a trail stones, reached the depth of about ment. through heavy snow with great difficulties -1680m, and stopped at the mouth of the By the night of January 9th all the expedi- when a big avalanche crossed the course next pit. This news, delivered to the camp tion members and equipment were just before the first group. It caught and at -1215 on the morning of January 5th, already on the surface. The next day was buried a front man, Anatolij Povjakalo. He brought all its population into a great spent for recovery and on January 11th was immediately dug out, frightened but excitement. Next, two pairs of explorers everything was prepared for evacuation safe. The night was spent in a forest and went to push the cave further and Denis by helicopter ordered for this date. in the afternoon of the next day, January Provalov went to the surface to bring this However, the helicopter had not arrived 14, the team met a track in the Sandripsh news to the rest of the world via mobile due to weather conditions in Sukhumi. canyon, led by local supporting person phone. On January 6th the news was The time had come to pay for such Vatik Vartanjan and a caver from Brest, reported to civilization. smooth work in the cave. During the night Sergey Krasko. Sergey had arrived by air The pit at -1680m turned out to be the the weather deteriorated dramatically in a day before to coordinate an expected last one in this expedition. It led to a big Arabika and on January 12th they bid rescue operation. This was a happy end chamber with a boulder choke in the far farewell to their hope for a helicopter: a of the active part of the expedition. end, the deepest point reached so far (- strong wind, heavy snowfall and low visi- On January 16 the weather improved to a 1710m). A "window" above the boulder bility. This continued through the next degree that allowed making a quick heli- choke led to a series of smaller break- night and the weather forecast for the copter fly to Arabika to take away the con- down chambers but gave no apparent coming few days, received via phone, served equipment. In Kiev and Moscow continuation. Four other expedition mem- was unfavorable. Eventually, the team the expedition members were greeted by Caves.com Page 22 Caves.com BRIEF NOTES ON THE ACKNOWLEDGEMENTS CAVE AND FURTHER The BASK and Alpindustria companies PERSPECTIVES based in Moscow donated some equip- The cave is developed in ment to the winter expedition. The Canon the thick-bedded and mas- representative office in Moscow spon- sive Upper Jurassic lime- sored us with video and photo cameras. stones, in the vault zone of We sincerely thank them for this help. the Berchil'sky anticline. The limestones become REFERENCES increasingly sandy starting from the depth of about Kiknadze, T.Z. 1972. Karst of the Arabika 300m, with maximum sand massif. Thilisi: Metzniereba. 245 pp. (in content in the depth interval russian). orchestras, champagne, flowers, caving of 400-600m, the feature previously noted Klimchouk, A.B. 1984. On impact of the friends, reporters and television crews. for the adjacent Kujbyshevskaja Cave. late Quaternary glaciations on the karst The main branch of the Krubera Cave development of the Arabika massif TECHNIQUE AND EQUIPMENT develops steeply in depth by vertical pits (Caucasus). Izvestia VGO (Leningrad), The exploration was made using standard separated by short meanders and shifts a 116 (2). 165-170. (in russian). European single-rope technique and little to the southern slope of the anticline. Klimchouk, A.B. 1990. Karst circulation equipment. The total rigging required over Apart from the "Non-Kujbyshevskaja" systems of the Arabika massif. Peschery 2000m of ropes and about 300 anchors. branch, which stretches for almost 500m (Caves), inter- university scientific trans- Almost everywhere ropes were rigged to the north west, the cave is looping with- actions, Perm: Perm University. 6-16. (in away from water flows and intense drips in a quite small area (400 by 400m), russian). so that no dry suits were required to work remains within a small tectonic block, and Klimchouk, A. 1991. Le grotte del massic- in the does not extend beyond the southern cio di Arabika. La Rivista del CAl, 112 (1). cave. ridge of the trough valley. 37-47. During the winter expedition two under- By both the degree of morphological Kruber, A. A. 1911. Karabi-Yuajla and the ground camps were used, at -500m and development and hydrologically, the cave Arabika massif. Zemlevedenie (Moscow), at -1215m respectively. The former camp, cedes to the adjacent Kujbyshevskaja 18 (3). (in russian). located at the bottom of P152, is subject Cave. Small water flow (up to 1 1/sec) Kruber, A.A. 1912a. The voyage to to rock fall hazard. For further works in appears in the cave at the depth of about Arabika. Estestviznanie i geografia. (in the bottom area a camp can be set up in 340m. It disappears and reappears on russian). the Chamber of Soviet Speleologists at - various levels but never increases consid- Kruber, A.A. 1912b. From observations of 1710m although a possibility of local erably. At its present bottom at -1710m karst in the vicinity of Gagra and Karabi- flooding due to boulder choke constriction (530m above sea level) the cave neither Yuajla. Zemlevedenie (Moscow), 19 (1-2). should be additionally evaluated. enters a main collector river passage nor (in russian). The camp at -1215m could accommodate shows any signs of considerable flooding Martel, E.A. 1909. La Cote dAzur Russe eight cavers. Exploration of the lower part that would indicate close proximity to its (Riviera du Caucase). Ch. XVI: La massif of the cave proceeded continuously in two base level collector. These features, de l'Arabika. Paris. shifts, through the work of four pairs of together with the previously proven con- Maruashvili, LI., Tintilozov, Z.K. and cavers. All the expedition members had a nection of the Arabikskaja system to large Changashvili, G.Z. 1961. The results of chance to work in the bottom area below springs at the Black Sea shore, suggests speleological explorations carried out in -1600m and nine of them were at the very clear potential to deepen the cave by at 1960 on the Arabika limestone massif. bottom. least 150-200m (estimated conservative- Izvestia AN GSSR (Tbilisi), XXVI (5). (in SURVEY AND DEPTH ESTIMATES ly) or up to 300- 350m with more opti- russian). The survey of the cave was performed mistic estimation. Maruashvili, LI., Tintilozov, Z.K and using Suunto and Soviet "geological" Equally realistic is the attempt to connect Changashvili, G.Z. 1962. Karst and compasses and clinometers. In addition, caves with entrances that are at higher ancient glaciation in Arabika. Absfracts of two Casio watch altimeters were used to elevations into the Krubera Cave main papers of the 2nd scientific session of control the depth by repeated incremental system. The best prospects are the near- speleologists. Thilisi: AN GSSR. (in russ- measurements. The depth of the lowest by Berchil'skaja Cave (-500m) entered ian). point in the cave was 1720m according to 150m above, and Martel's Cave located Maruashvili, LI. and Tintilozov, Z.K. 1963. altimeters, but 1710m according to the cli- some 80m above. Hence, the possibilities The results of the recent speleological nometer measurements; the latter figure of gaining a 2000m + system in this area explorations in the karstic belt of the was eventually taken as an "official" one. in the near future are exceptionally good. Western Georgia in 1957- 1960. In general, the resultant map and profile The Ukrainian Speleological Association Zemlevedenie (Moscow), nov. ser. VI. (in (Figure 4) correspond to the and CAVEX Association will continue russian). BCRA Grade 4. strong and regular efforts during next sev- In September 2000 the MRDE team eral years, both in summer and winter made independent depth measurements periods, in order to fully explore Krubera up to the -1410m point with two precise and other caves of the Ortobalagan altimeters and found a coincidence within trough valleys with an ultimate goal to five meters with the depth estimates for explore the first 2000m + cave on the various points previously made on the . basis of clinometer survey.

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