A small team returned to Mulu in 2010 to focus on photographic, surveying and scientific objectives in the Southern Hills region of the park.
The expedition was in the field between the 4th and 25th May. This year only a small team returned to Mulu with different objectives to previous expeditions. This time the focus was not on exploration but surface survey, science and photography. The Southern Hills was the main objective for most of this work. Many of the caves in the massif had been explored during the early expeditions which took place between 1978 and 1984, and although the caves were surveyed and published at the time, there was no attempt to link them altogether. The elevations of the caves were needed to assist the scientists with their development work and the exact positions around the mountain would enable more accurate maps and graphics to be drawn. Over the course of the trip some 15km of surface traverse were surveyed around the Southern Hills linking up the caves of Deer, Green, Snake, Mayday, Deerwater, Stonehorse, Paris, Fernrock, Surfrace, Daniels and a number of smaller caves and significant surface features.
Along side the survey work, Dr Gina Moseley and Professor Pete Smart, continued the latest scientific research programme into the timing of cave development, which had commenced during the 2009 expedition. This took the programme into the caves of the Southern Hills and southern Gunung Api. Sites were targeted for sampling of quartz, speleothem and sediment in Deer Cave, Clearwater Cave, Green Cave, Lagangs Cave, Racer Cave and Stone Horse Cave. Analysis of these samples using Al26-Be10 cosmogenic burial dating, U-Pb dating and paleomagnetic dating respectively, will assist further in understanding cave development and rates of fluvial incision within the Park.
A number of photographic trips were undertaken to caves close to park headquarters. Previously the only major photos the Mulu Caves Project had of these caves were taken during the original explorations over 25 years ago on film format cameras. It was intended to start a project to capture the magnificence of these caves on modern digital equipment and improve our photo database. Deer, Green, Racer, Lagans, Wind and Stonehorse were all visited for this reason. Several of these caves are used as tourist or adventure locations and it is hoped that some of the photographs may be used for educational or promotional purposes with the park.
It was not intended to seek out new discoveries on this expedition, however, in the course our other work a number of small discoveries were made. Most of these had already been entered by bird nesters. These were all surveyed and the Southern Hills database increased by 2417m. This included three short caves in the isolated Batu which were already used for adventure caving by the national park.
For the second expedition running we had a member who had travelled directly between the two great caves of Vietnam’s Hang Son Dong and Mulu’s Deer Cave. Again the opinion of that member was that there was no part of Hang Son Dong that was bigger than the main passage of Deer Cave. This must call into question the subjective claims that Hang Son Dong is the largest cave passage in the world.