Impact of global cooling on Early Cretaceous high pCO2 world during the Weissert Event
The Weissert Event ~133 million years ago marked a profound global cooling that punctuated the Early Cretaceous greenhouse. We present modelling, high-resolution bulk organic carbon isotopes and chronostratigraphically calibrated sea surface temperature (SSTs) based on an organic paleothermometer (t...
Published in: | Nature Communications |
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Main Authors: | , , , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Nature Research
2021
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Subjects: | |
Online Access: | https://oceanrep.geomar.de/id/eprint/54156/ https://oceanrep.geomar.de/id/eprint/54156/1/s41467-021-25706-0.pdf https://oceanrep.geomar.de/id/eprint/54156/2/41467_2021_25706_MOESM3_ESM.xlsx https://oceanrep.geomar.de/id/eprint/54156/8/41467_2021_25706_MOESM1_ESM.pdf https://doi.org/10.1038/s41467-021-25706-0 |
Summary: | The Weissert Event ~133 million years ago marked a profound global cooling that punctuated the Early Cretaceous greenhouse. We present modelling, high-resolution bulk organic carbon isotopes and chronostratigraphically calibrated sea surface temperature (SSTs) based on an organic paleothermometer (the TEX86 proxy), which capture the Weissert Event in the semi-enclosed Weddell Sea basin, offshore Antarctica (paleolatitude ~54 °S; paleowater depth ~500 meters). We document a ~3–4 °C drop in SST coinciding with the Weissert cold end, and converge the Weddell Sea data, climate simulations and available worldwide multi-proxy based temperature data towards one unifying solution providing a best-fit between all lines of evidence. The outcome confirms a 3.0 °C ( ±1.7 °C) global mean surface cooling across the Weissert Event, which translates into a ~40% drop in atmospheric pCO2 over a period of ~700 thousand years. Consistent with geologic evidence, this pCO2 drop favoured the potential build-up of local polar ice. |
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