Year: 2020
Type: article
Abstract: Few palaeoclimate archives beyond the polar regions preserve continuous and datable palaeotemperature proxy time series over multiple glacial-interglacial cycles. This hampers efforts to develop a more coherent picture of global patterns of past temperatures. Here we show that Mg concentrations in a subaqueous speleothem from an Italian cave track regional sea-surface temperatures over the last 350,000 years. The Mg shows higher values during warm climate intervals and converse patterns during cold climate stages. In contrast to previous studies, this implicates temperature, not rainfall, as the principal driver of Mg variability. The depositional setting of the speleothem gives rise to Mg partition coefficients that are more temperature dependent than other calcites, enabling the effect of temperature change on Mg partitioning to greatly exceed the effects of changes in source-water Mg/Ca. Subaqueous speleothems from similar deep-cave environments should be capable of providing palaeotemperature information over multiple glacial-interglacial cycles.
Source: Nature Communications
Institutions: Centre National de la Recherche Scientifique, The University of Melbourne, Laboratoire Environnements, Dynamiques et Territoires de Montagne, Université Savoie Mont Blanc, University of Pisa, Istituto Nazionale di Geofisica e Vulcanologia, INGV Sezione di Pisa, Institute of Geosciences and Earth Resources, Université de Versailles Saint-Quentin-en-Yvelines, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Laboratoire des Sciences du Climat et de l'Environnement, University College London, Australian National University, Australian Nuclear Science and Technology Organisation, University of Florence
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
SDG: Climate action
Open Access status: gold
Estimated APC paid: $5,380
Funder: Australian Research Council
OpenAlex ID: W3092013448