Drip rate and tritium activity in the Niedźwiedzia Cave system (Poland) as a tool for tracking water circulation paths and time in karstic systems

The Niedźwiedzia Cave system is composed of 3 horizontal levels of passages and cham-bers. Changes in the drip rate of water from the upper level stalactites correlate well with changes in precipitation intensity. The transition time between the surface and the upper level of the cave was es-timated to 14 days. Drip sites in the middle and lower levels of the cave exhibited two types of re-charge: some did not correlate with precipitation intensity, whereas others correlated well with rain events. The transition times for the latter sites were estimated to be greater than 6 months. This esti-mate was confirmed by the calculation of the transition time based on tritium activity. The oldest wa-ter in the entire karst system was observed in a karst spring. The mean tritium age for this water dur-ing winter was estimated to be 3.9 ± 0.6 yr. More precise calculations of the tritium age of karst water require longer precipitation activity datasets.