2023-08-21 バーミンガム大学
◆この研究は、地球の気候が大きく変動し、生態系と炭素循環と密接に関連していることを示し、地球の気候と生態の複雑性を理解する上で貴重な情報を提供しています。
<関連資料>
- https://www.birmingham.ac.uk/news/2023/mississippi-mud-reveals-secrets-of-antarcticas-ancient-expansion
- https://www.nature.com/articles/s41467-023-39806-6
更新世-更新世移行期の海面低下に関する複合プロキシーの証拠 Multi-proxy evidence for sea level fall at the onset of the Eocene-Oligocene transition
Marcelo A. De Lira Mota,Tom Dunkley Jones,Nursufiah Sulaiman,Kirsty M. Edgar,Tatsuhiko Yamaguchi,Melanie J. Leng,Markus Adloff,Sarah E. Greene,Richard Norris,Bridget Warren,Grace Duffy,Jennifer Farrant,Masafumi Murayama,Jonathan Hall & James Bendle
Nature Communications Published:08 August 2023
DOI:https://doi.org/10.1038/s41467-023-39806-6
Abstract
Continental-scale expansion of the East Antarctic Ice Sheet during the Eocene-Oligocene Transition (EOT) is one of the largest non-linear events in Earth’s climate history. Declining atmospheric carbon dioxide concentrations and orbital variability triggered glacial expansion and strong feedbacks in the climate system. Prominent among these feedbacks was the repartitioning of biogeochemical cycles between the continental shelves and the deep ocean with falling sea level. Here we present multiple proxies from a shallow shelf location that identify a marked regression and an elevated flux of continental-derived organic matter at the earliest stage of the EOT, a time of deep ocean carbonate dissolution and the extinction of oligotrophic phytoplankton groups. We link these observations using an Earth System model, whereby this first regression delivers a pulse of organic carbon to the oceans that could drive the observed patterns of deep ocean dissolution and acts as a transient negative feedback to climate cooling.
