Reserve Naturelle de Namoroka

Preparing "Namoroka 1992" was like one of those defective showers, torturing you with comfortably warm water one second and ice cold water in the next.

We contacted the American caver Carol Jo Rushin-Bell, who was working on an US-Aid project in Madagascar, and everything looked quite easy: The time consuming purchase of carbide and white gas, normally including a long and endurous search in the capital Antananarivo, was done well in advance. Also a 4x4 vehicle was arranged, including a fantastic driver David.

However, at the end of april political riots started in Madagascar, leaving the island in a somehow difficult situation. This, and additional news about the unattainability of Namoroka, nearly let us cancel our expedition. Later on, there were bandits reported to be lurking around Namoroka, and we remembered a french expedition to Kelifely, situated in close vicinity, which got stuck due to the bandit problems some years ago. And finally Carol Jo could't get free time for the expedition.

Nevertheless our permission to enter and work in the strictly protected Reserve Naturelle de Namoroka was given without any problems, so we decided to start with some mixed feelings of what will be in the next weeks.

Travel to the Reserve

Sor our team of 6 cavers reached Madagascar with mixed feelings in the middle of July. Carol Jo's organisation had worked well and we found ourselves well equipped and soon on the way to Majunga the next day, in a Landcruiser driven by David. Afer one lost day, waiting for the age-worn ferry to cross the river Betsiboka at Majunga and some gruelling hours of driving along a 140 km trail, we reached the village Soalala, where only 60 km separated us from the Reserve Naturelle de Namoroka.

Unfortunally, there was no longer a ferry across the river Andranomavo, so we had to leave the car in Soalala and continue on foot to the Station Forestiere de Vilanandru (east of the Reserve). Our equipment was carried by bullock-cart. After one and a half day of walking through the hot palm-tree savanna, along sandy pathes, and through kneedeep rivers, the Reserve Naturelle de Namoroka was lying in front of us - and the locals definitely knew nothing about bandits!

Survey camp

Our camp was build in a shady, idyllic site near the entrance of Anjohiambovinomby cave, on the southeast border of the spectacular karst area of Namoroka. The triangular shaped plateau of 160 km^2 consists of very hard-crystalline Jurassic limestones with dolomite layers at its base. Lots of canyons, caused by cracks and faults, dissect the plateau into smaller massifs with extensions up to 10 km^2 and bordered by 80 m high vertical walls. The surface of these massifs is covered with dense razorsharp pinnacles and it is impossible to make any attempt to cross the massifs exept through the canyons. These pinnacles are called Tsingy in Madagascar.

Survey of Anjohiambovonomby

The main aim was the survey of the cave Anjohiambovonomby, which is described as a several kilometre long system of interconnected passages (Decary & Kiener 1971). During the rainy season, a considerable amount of water coming from the southern laterite-covered karst slopes accumulates at the foot of the Anjohiambovonomby tsingy. Even during the dry season there is water outside the cave, one of the few places in the whole area of Namoroka. Obviously, this stagnant water enlarged the network of fissures in Anjohiambovonomby, creating a labyrinthic cave, which developes along the edge of the karst block and includes numerous entrances. Most of the galeries are well proportioned with pretty formations, but threre are also lots of narrow crawls in the western extension of the cave. To explore our survey of Anjohiambovonomby with some photos of the cave, follow this link.

We have been unable to find a passage leading into the heart of the tsingy until one team discovered a key point in the middle section of the cave after three days of mapping. A small continuation with a current of air was leading north - and it became bigger! After a series of well decorated chambers, we reached one of the most impressive clefts of Anjohiambovonomby, leading to a 6 m descent. Beneath us, the surface of a deep lake was visible. Two members decided to survey it by swimming, but the end of the water passage was reached soon. Free diving attempts in the very clear, static water proved, that there are only minor possibilities for continuations by divers.

The passages of Anjohiambovonomby often contain remarkable calcite floors, in some cases up to five, one above the other. This seems to coincide with the observations of Rossi (1981), who postulates five changes in paleoclimate in western Madagascar between humid and arid types in the last 40.000 years.

After one week of mapping, there were no obvious continuations left. Now Anjohiambovonomby, with 4.6 km length, is the seventh longest cave in Madagascar.

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