Global analysis reveals climatic controls on the oxygen isotope composition of cave drip water
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Date
2019-07-05
Journal Title
Journal ISSN
Volume Title
Publisher
Springer Nature
Abstract
The oxygen isotope composition of speleothems is a widely used proxy for past climate change. Robust use of this proxy depends on understanding the relationship between precipitation and cave drip water δ18O. Here, we present the first global analysis, based on data from 163 drip sites, from 39 caves on five continents, showing that drip water δ18O is most similar to the amount-weighted precipitation δ18O where mean annual temperature (MAT) is < 10 °C. By contrast, for seasonal climates with MAT > 10 °C and < 16 °C, drip water δ18O records the recharge-weighted δ18O. This implies that the δ18O of speleothems (formed in near isotopic equilibrium) are most likely to directly reflect meteoric precipitation in cool climates only. In warmer and drier environments, speleothems will have a seasonal bias toward the precipitation δ18O of recharge periods and, in some cases, the extent of evaporative fractionation of stored karst water. © 2019, The Author(s)
Description
Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License.
Keywords
Oxygen isotopes, Caves, Water influx, Global analysis, Climate, Hydrology, Paleoclimatology
Citation
Baker, A., Hartmann, A., Duan, W., Hankin, S., Comas-Bru, L., Cuthbert, M. O., Treble, P. C., Banner, J., Genty, D., Baldini, L. M., Bartolomé, M., Moreno, A., Pérez-Mejías, C. & Werner, M. (2019). Global analysis reveals climatic controls on the oxygen isotope composition of cave drip water. Nature communications, 10(1), 1-7. doi:10.1038/s41467-019-11027-w