3-7 September 2018
Audimax | Kiel University
Europe/Berlin timezone

Unravelling the cause of OAE 1a (~120 Myr), one of the largest ocean deoxygenation events of the last 200 million years

Not scheduled
Audimax | Kiel University

Audimax | Kiel University

Christian-Albrechts-Platz 2 | 24118 Kiel | GERMANY
Poster 09 Ocean Deoxygenation - How the Past can Inform the Future


Markus Adloff


Oceanic Anoxic Event (OAE) 1a took place during the early Aptian (~120 Ma) and represents one of the largest disruptions in ocean oxygenation and biogeochemical cycles of the last 200 million years. So far it has been difficult to constrain the processes and mechanisms that drove this event, hindering a holistic understanding of the relative importance of external forcing and internal feedbacks during this perturbation. For the first time, we study changes in the global carbon cycle at the onset of OAE 1a combining proxy data and a global biogeochemical ocean model of intermediate complexity (cGENIE). In a series of experiments, cGENIE was forced to follow the atmospheric stable carbon isotope (δ13C) evolution obtained from proxy data throughout the onset of OAE 1a using a variety of timescale assumptions and CO2 change scenarios. Depending on the scenario, the model calculates for each experiment the magnitude and δ13C signature of carbon inputs required to reproduce the recorded δ13C excursion. Our results suggest that the majority of the deoxygenation was driven by emissions from sedimentary organic carbon reservoirs and volcanic sources and not biogenic methane. Also low emission scenarios comply with proxy data constraints, highlighting the potentially crucial role of internal feedbacks in the extreme ocean deoxygenation during OAE 1a.

Are you a SFB 754 / Future Ocean member? No
Affiliation School of Geographical Sciences, University of Bristol
Position PhD Candidate
Email Address markus.adloff@bristol.ac.uk

Primary authors

Markus Adloff Sarah Greene B. David A. Naafs Fanny Monteiro Dan Lunt Stephen Hesselbo Andy Ridgwell

Presentation Materials

There are no materials yet.