Continuous 3-year record of cave methane, trace gases and environmental data collected in Jenolan Caves, Australia

Speleothem palaeo-climate records rely on the transfer of external weather and climate signals to growing speleothems in the cave environment. Both cave atmosphere and drip-water chemistry affects this signal transfer. Speleothem growth may be detected by measuring the isotopic composition of CO2 in the cave atmosphere. Our study was designed to measure the rapid response of cave atmosphere to changes in external weather and the incorporation of environmental signals into speleothems. The approach to data collection was to define the sources and sinks of trace gases in the cave measured at high frequency (hour) to match rapid changes in weather, principally temperature, which drives convective cave ventilation.
This time series data-set collected at the Jenolan Caves experiment site in NSW, Australia is the first long-term (3 yr) continuous measurement of d13C in CO2 and CH4 in-situ in a cave. Spectroscopic methods, Cavity Ring Down Spectroscopy (CRDS) and Fourier Transform Infra Red (FTIR) were used. In addition to d13C in CO2 and CH4, time-series data for N2O, CO and 222Rn were also recorded.