Reconstructing a deep time Earth system: The penultimate ice house

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• Prof Isabel Motañez (UC Davis) and Sophia Macarewich (U Michigan)
• Thursday 22 April 2021, 15:00-16:00
• https://zoom.us/j/98188045146.

If you have a question about this talk, please contact Oliver Shorttle.

Earth system science, the study of our planet as an integrated set of subsystems that drive planetary function is applicable to the geologic past, i.e., the deep time, made possible by the advent of high precision radioisotope dating, the potential for astronomically calibrating stratigraphic intervals, and the application of Earth System (climate) Models and process-based ecosystem models to deep time studies. In this talk we discuss three components of our collective effort to develop a ‘whole-Earth’ reconstruction of the penultimate icehouse—the Late Paleozoic Ice Age (LPIA), _{300 Ma. For the first component, we present a multi-proxy record of atmospheric CO2 over 40 million years of this icehouse and its turnover to a permanent greenhouse revealing CO2 variability (}160 and 750 ppm) in-step with the glaciation history and with repeated restructuring of Pangaean tropical biomes on the eccentricty to million-year scales. In the second component, we couple the atmospheric composition records with plant fossil measurements and process-based ecosystem modelling to reconstruct the paleo-physiology/functioning of the extinct plants and to suggest possible ecosystem-scale vegetation-climate-CO2 feedbacks that would have influenced water cycling, surface runoff and weatherability, and organic carbon burial. In the third component, we use an isotope-enabled Earth system model to simulate the influence of glacial-interglacial fluctuations in atmospheric CO2 on epicontinental to global-scale ocean circulation and oxygen isotopic composition. This ‘systems’ perspective of the Earth’s penultimate icehouse reveals unique insights into the response of land-atmosphere-ocean interactions to a range of atmospheric CO2 within that projected for our future.

This talk is part of the Earth2Earth series.

This talk is included in these lists:

• Department of Earth Sciences Seminars (downtown)
• Department of Earth Sciences seminars
• Earth2Earth
• https://zoom.us/j/98188045146
• ps635

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