Spot measurements and new installations of continuous monitoring equipment of CARDIKARST were carried out in the Postojnska jama–Planinska jama cave system. On the 14th September, Franci and Vanessa visited the Postojna Cave system to perform spot measurements of water geochemistry and CO2 concentrations in both air and water. Water temperatures were 15–17°C, electrical conductivity around 450 µS/cm and dissolved oxygen ranged from 81% to 97%. At the site in Crna Jama, we installed the first prototype instrument to simultaneously continuously measure CO2 concentrations in air and water. Another instrument for continuously measuring water conductivity, temperature and pressure was installed at a strategic location in the mid-point of the cave system. Importantly, the first continuous data were downloaded from the previously installed instruments showing that they were (thankfully) functioning well.
On the 20th September, Franci and Vanessa then visited Planina Cave, which is an important monitoring site because it is where the water that travels underground from the Postojna Cave system reappears, bringing with it chemical information about conditions in the flooded part of the karst system. It was Vanessa’s first visit to Planina Cave: “The trip was amazing! Planina Cave was far more beautiful and much larger than I had imagined. To reach the sampling site we had to take an inflatable boat and travel a significant distance upstream, luckily in calm waters. Shining our lights down, the water was crystal clear and we saw large numbers of cave creatures. The sensation of floating in silence in the semi-darkness gave a feeling of soothing tranquility, completely detached from the worries of the world outside. I’m really looking forward to going back (obviously for the science)!”
Text: Vanessa Johnston
Photos: Franci Gabrovšek & Vanessa Johnston
