News: Exploring Large River Caves in West Papua

The Aouk Underground River. Photo: Tommaso Biondi

An Italian team, Achleoos Geo Exploring, is exploring and documenting underground rivers with very high flow rates.

In a series of expeditions from 2012 to 2017 they have been exploring the Aouk River System and other caves in West Papua. This system is formed from several river passages and large dolines with an average annual flow of approximately 50 cumecs. The system is still only partially explored and at present has a known total length of 6 km. In terms of water flow, this makes it one of the largest river caves so far explored in the world, being of the same order of magnitude as the Xe Bang Fai cave in Laos and the Gebihe system in China. The Aouk River System’s catchment is about 600km2 and has over 6m of rainfall annually.

Along the lower course of the Aouk River, called the Kladuk, the team has also identified and documented the existence of what could be the largest sinkhole-spring karst system in the world. The Kladuk River Passage, although currently unexplored, is closed by sumps and has an average annual flow thathas been calculated at about 150 – 180 cumecs.

Both systems, the Aouk and the Kladuk, have important historical and anthropological features related to the mythology of the Mej Mare and Mej Prat peoples. In  local mythology, gods and ancestors live and move in an underground world, sometimes called Worn’su, and life and death are linked to the concepts of the disappearing rivers. The team have started to collect myths relating to these vast cavities and are beginning to understand them.

Exploring these large underground rivers is very different from working in normal caves and requires acombination of skills from kayaking, canyoning, caving and river-rescue. The usual difficulties of Tyrolean and other rope techniques are increased by the force of the water and the daily risk of floods. The team has even developed new techniques to help the, make progress and new tools, such as wet water tools similar to ice axes.

“Wet-Water Tools” at Ayrim Cave
Photo: Marc Faverjon

The expedition has also carried out a brief survey in the central Highland area including the resumption of exploration in the Kutiulerek Cave, which had previously been partially explored by an English-Australian expedition in 1996. This cave is now over 8 km long and is longest cave in West Papua, and is amongst the longest in Indonesia.It still has many new leads to explore. In both areas, exploration will be continued by a further expedition in the coming months.

Papua 2017 Expedion Members: Ivan Vicenzi (Gruppo Speleologico Sacile), Thomas Pasquini (Gruppo Speleologico Piemontese); Katia Zampatti (Gruppo Speleologico Brescia), Andrea Benassi (Società Speleologica Saknussem); Riccardo Pozzo (Gruppo Speleologico Biellese); Tommaso Biondi, Marc Faverjon e Paolo Turrini.

Thanks to our technical sponsors and patrons: Petzl; Rodcle Equipment; Korda’s; CT Climbing technology; Kikko Lamp; Repetto Sport; Enomad; AlpackaRaft; Società Geografica Italiana; Società Speleologica Italiana; Museo di Storia Naturale di Firenze; Gruppo Speleologico Sacile.

Correspondent: Andrea Benassi