Temperature variations in caves induced by atmospheric pressure variations—Part 2: Unveiling hidden thermal signals

Researchers have uncovered subtle temperature signals in caves, as small as a few thousandths of a degree Celsius, which are obscured by atmospheric pressure variations. By subtracting the expected pressure-induced temperature (PIT) variations from observed data, the study identified human presence signals with relaxation periods exceeding several days and long-term cumulative effects. Additionally, non-stationary thermal processes such as transient air currents, infiltration, and evaporation-condensation were detected, exhibiting a scale-free amplitude spectrum. Notably, a weak but unambiguous peak at approximately 82.2 ± 0.8 minutes in Chauvet Cave suggests a Helmholtz-type resonance. These findings highlight the complexity of underground thermal dynamics, crucial for evaluating preservation strategies and resilience under climate change or artificial influences.

Perrier, F., Bourges, F., Girault, F., Mouël, J.-L. L., Genty, D., Lartiges, B., Losno, R., & Bonnet, S. (2023). Temperature variations in caves induced by atmospheric pressure variations—Part 2: Unveiling hidden thermal signals. Geosystems and Geoenvironment, 2(2), 100146. https://doi.org/10.1016/j.geogeo.2022.100146