MICROCLIMATE AND HYDROLOGICAL MONITORING IN KARST SYSTEM FROM MID-WEST BRAZIL

Monitoring of Karst system involving the measuring of microclimate and hydrological parameters inside and outside of caves helps on the interpretation of paleoclimate proxy data in speleothems. This research present three years of monitoring of stable isotopes on the rainfall water, drip water and associated calcite (grown on glass plates), as well, air temperature, relative humidity, drip rates and PCO₂ in Jaragua Cave, Mid-West of Brazil.

In this study, water isotopes in the rainfall vary seasonally in response to rainfall amount. Most negative values are observed during wet periods independently of season. Inside of cave, the isotope on drip water and carbonate presents a smoothed variability in relation to rainfall. The two drip rates monitored present distinct variability with nonlinear behavior. The air temperature present a seasonal variability with range of ~0.5 °C and the relative humidity is practically constant in 100% during all monitoring period, indicating that δ¹⁸O analyses in stalagmites from this cave probably is the good indicator from paleorainfall.