Impact of global cooling on Early Cretaceous high pCO2 world during the Weissert Event.

Autor: Cavalheiro, Liyenne, Wagner, Thomas, Steinig, Sebastian, Bottini, Cinzia, Dummann, Wolf, Esegbue, Onoriode, Gambacorta, Gabriele, Giraldo-Gómez, Victor, Farnsworth, Alexander, Flögel, Sascha, Hofmann, Peter, Lunt, Daniel J., Rethemeyer, Janet, Torricelli, Stefano, Erba, Elisabetta
Předmět:
Zdroj: Nature Communications; 9/13/2021, Vol. 12 Issue 1, p1-11, 11p
Abstrakt: 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. Modelling and sea surface temperature proxy data from the Weddell Sea document a 3–4 °C drop coinciding with the Early Cretaceous Weissert Event. Temperature data worldwide confirm a 3.0 °C global mean surface cooling, equivalent to a ~40% drop in atmospheric pCO2, favouring local polar ice. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
Externí odkaz: