Indian Ocean glacial deoxygenation and respired carbon accumulation during mid-late Quaternary ice ages.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37563128.
- Also identified by DOI 10.1038/s41467-023-40452-1 and PMC identifier 10415292.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Reconstructions of ocean oxygenation are critical for understanding the role of respired carbon storage in regulating atmospheric CO<sub>2</sub>. Independent sediment redox proxies are essential to assess such reconstructions. Here, we present a long magnetofossil record from the eastern Indian Ocean in which we observe coeval magnetic hardening and enrichment of larger, more elongated, and less oxidized magnetofossils during glacials compared to interglacials over the last ~900 ka. Our multi-proxy records of redox-sensitive magnetofossils, trace element concentrations, and benthic foraminiferal Δδ<sup>13</sup>C consistently suggest a recurrence of lower O<sub>2</sub> in the glacial Indian Ocean over the last 21 marine isotope stages, as has been reported for the Atlantic and Pacific across the last glaciation. Consistent multi-proxy documentation of this repeated oxygen decline strongly supports the hypothesis that increased Indian Ocean glacial carbon storage played a significant role in atmospheric CO<sub>2</sub> cycling and climate change over recent glacial/interglacial timescales.