Article
 

North Pacific deglacial hypoxic events linked to abrupt ocean warming

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/articles/j96022490

Descriptions

Attribute NameValues
Creator
Abstract
  • Marine sediments from the North Pacific document two episodes of expansion and strengthening of the subsurface oxygen minimum zone (OMZ) accompanied by seafloor hypoxia during the last deglacial transition. The mechanisms driving this hypoxia remain under debate. We present a new high-resolution alkenone palaeotemperature reconstruction from the Gulf of Alaska that reveals two abrupt warming events of 4–5 degrees Celsius at the onset of the Bølling and Holocene intervals that coincide with sudden shifts to hypoxia at intermediate depths. The presence of diatomaceous laminations and hypoxia-tolerant benthic foraminiferal species, peaks in redox-sensitive trace metals, and enhanced ¹⁵N/¹⁴N ratio of organic matter, collectively suggest association with high export production. A decrease in ¹⁸O/¹⁶O values of benthic foraminifera accompanying the most severe deoxygenation event indicates subsurface warming of up to about 2 degrees Celsius. We infer that abrupt warming triggered expansion of the North Pacific OMZ through reduced oxygen solubility and increased marine productivity via physiological effects; following initiation of hypoxia, remobilization of iron from hypoxic sediments could have provided a positive feedback on ocean deoxygenation through increased nutrient utilization and carbon export. Such a biogeochemical amplification process implies high sensitivity of OMZ expansion to warming.
Resource Type
DOI
Date Available
Date Issued
Citation
  • Praetorius, S. K., Mix, A. C., Walczak, M. H., Wolhowe, M. D., Addison, J. A., & Prahl, F. G. (2015). North Pacific deglacial hypoxic events linked to abrupt ocean warming. Nature, 527(7578), 362-366+. doi:10.1038/nature15753
Journal Title
Journal Volume
  • 527
Journal Issue/Number
  • 7578
Rights Statement
Funding Statement (additional comments about funding)
  • This work was supported by NSF grants AGS-0602395 (Project PALEOVAR, A.C.M.) and OCE-1204204 (A.C.M. and F.G.P.), and an NSF graduate research fellowship for S.K.P.; J.A.A. was supported by the USGS Climate and Land Use Change Research and Development Program and the Volcano Science Center.
Publisher
Peer Reviewed
Language
Replaces

Relationships

Parents:

This work has no parents.

Items

Thumbnail Title Date Uploaded Visibility Actions
file details PraetoriusS.CEOASNorthPacificDeglacial.pdf 2017-07-26 Public Download