Mulu 2019 Expedition

Following continued exploration of the Mulu Caves over many years, the primary aim for the Mulu 2019 expedition was to further explore the system and connect a number of caves in the Southern peninsula of Gunung Api. This focused on trying to join Cave of the Winds, Racer Cave, Easter Cave and Lagangs to significantly lengthen the Clearwater System. A sump from Cave of the Winds was proven to connect to Racer, so all that remains is for a diver to pass through. Lagangs and Easter were not connected but significant extensions were found. Additional exploration was completed in the northern end of Clearwater towards the Blackrock connection. This has opened up interesting leads to be examined by future expeditions and alongside this exploration, the team undertook further scientific work that examined microbiological features found in the cave. This work had originally aimed to examine four types of secondary deposits but also found unusual moonmilk deposits and an interaction between bird guano and host rock, which leads to highly aggressive dissolution. These early field observations suggest that there is a significant, but little understood microbial ecosystem within the caves, driven by the temperatures, humidity and uniquely high levels of trogloxene organic carbon input into the system.