Speleothem-inferred sea-level rise during marine isotope stage 11
Abstract
Marine isotope stage 11 at 430-390 thousand years age (ka) has been revealed as the warmest period over the past 800 thousand years, with the highest eustatic sea level reaching 6-13 m above the present-day value. However, the timing of the sea level rise and the source of the melt water are still in debate. Here, we present a speleothem-inferred sea-level record from 430-390 ka from northern Italy. The results reveal an extreme 18O-depleted event during 397 to 405 ka, with the δ18O fluctuations from -5 to -7‰. Combining planktonic foraminiferal δ18O and Ti/Al records of Mediterranean marine cores, our speleothem Mg/Ca and Sr/Ca records suggest that this depletion could not be attributed to changes in precipitation and/or African monsoon. We interpret the event as the final melt-water pulse in late MIS 11 to induce an occurrence of highstand of sea level. Based on current ice-sheet melting simulations, this18O-depletion pulse was most likely caused by Antarctica ice-sheet collapse at MIS 11.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMPP51F1426H
- Keywords:
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- 1009 Geochemical modeling;
- GEOCHEMISTRY;
- 4914 Continental climate records;
- PALEOCEANOGRAPHY;
- 4924 Geochemical tracers;
- PALEOCEANOGRAPHY;
- 4994 Instruments and techniques;
- PALEOCEANOGRAPHY