Journal article
Controls on rainfall variability in the tropical South Pacific for the last 350 years reconstructed from oxygen isotopes in stalagmites from the Cook Islands
M Faraji, A Borsato, S Frisia, DP Mattey, RN Drysdale, DC Verdon-Kidd, R Malcolm, A Marca
Quaternary Science Reviews | PERGAMON-ELSEVIER SCIENCE LTD | Published : 2022
Abstract
The hydroclimate of the South Pacific is highly variable on a range of timescales, however, the brevity of instrumental data in the region complicates the detection and attribution of this variability. Annually laminated speleothems may fill this knowledge gap by providing paleo-hydroclimate proxy data extending beyond the instrumental period. In this study, replicated oxygen isotope (δ18O) time series from two stalagmites from Pouatea (Pu17) and Nurau (Nu16) caves in the southern Cook Islands were used to reconstruct the variability of effective infiltration over the past 350 years (1672–2019 CE) based on observational rainfall data and cave monitoring and calcite farming experiments. The r..
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Awarded by Australian Government
Funding Acknowledgements
Many thanks to the Cook Islands Meteorological Service for granting us permission to access historic precipitation data held at NIWA for this work, and thanks to Andrew Lorrey for providing the rainfall data. Special thanks to the landowners, people and Island Council, and to the National Research Committee of the Cook Islands for permission to explore the caves of Atiu and take samples, and to Tura Koronui and George Mateariki, who introduced us to the caves in Atiu. Adam Hartland, John Hellstrom and Garry Smith participated in the fieldwork. The cave water samples were partly analyzed at the West Australian Biogeochemistry Centre by Grzegorz Skrzypek. This study was supported by the Australian Research Council Discovery Project grant DP160101058. M.F. was supported by the Australian Government through an "Australian Government Research Training Program Scholarship" and was also supported by the Australian Institute of Nuclear Science and Engineering through a Postgraduate Research Award (award ALNSTU12486). We would also like to thank the editor and two anonymous reviewers for their constructive comments and suggestions that greatly improved the quality of this manuscript.