Paleoceanographic insights on recent oxygen minimum zone expansion; lessons for modern oceanography

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doi: 10.1371/journal.pone.0115246
Author(s): Moffitt, Sarah E.; Moffitt, Russell A.; Sauthoff, Wilson; Davis, Catherine V.; Hewett, Kathryn; Hill, Tessa M.
Author Affiliation(s): Primary:
University of California at Davis, Bodega Marine Laboratory, Bodega Bay, CA, United States
Marine Conservation Institute, United States
Volume Title: PLoS One
Source: PLoS One, 2015(e0115246). Publisher: Public Library of Science, San Francisco, CA, United States. ISSN: 1932-6203
Note: In English. NSF grants OCE-0825322 and OCE-1255194. 238 refs.; illus., incl. 5 tables, sketch maps
Summary: Climate-driven Oxygen Minimum Zone (OMZ) expansions in the geologic record provide an opportunity to characterize the spatial and temporal scales of OMZ change. Here we investigate OMZ expansion through the global-scale warming event of the most recent deglaciation (18-11 ka), an event with clear relevance to understanding modern anthropogenic climate change. Deglacial marine sediment records were compiled to quantify the vertical extent, intensity, surface area and volume impingements of hypoxic waters upon continental margins. By integrating sediment records (183-2,309 meters below sea level; mbsl) containing one or more geochemical, sedimentary or microfossil oxygenation proxies integrated with analyses of eustatic sea level rise, we reconstruct the timing, depth and intensity of seafloor hypoxia. The maximum vertical OMZ extent during the deglaciation was variable by region: Subarctic Pacific (∼600-2,900 mbsl), California Current (∼330-1,500 mbsl), Mexico Margin (∼330-830 mbsl), and the Humboldt Current and Equatorial Pacific (∼110-3,100 mbsl). The timing of OMZ expansion is regionally coherent but not globally synchronous. Subarctic Pacific and California Current continental margins exhibit tight correlation to the oscillations of Northern Hemisphere deglacial events (Termination IA, Bolling-Allerod, Younger Dryas and Termination IB). Southern regions (Mexico Margin and the Equatorial Pacific and Humboldt Current) exhibit hypoxia expansion prior to Termination IA (∼14.7 ka), and no regional oxygenation oscillations. Our analyses provide new evidence for the geographically and vertically extensive expansion of OMZs, and the extreme compression of upper-ocean oxygenated ecosystems during the geologically recent deglaciation.
Year of Publication: 2015
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Bathymetry; Benguela Current; California Current; Cenozoic; Chemical composition; DSDP Site 480; Deep Sea Drilling Project; Deglaciation; East Pacific; Equatorial Pacific; Foraminifera; Gulf of California; Humboldt Current; IPOD; Indian Ocean; Invertebrata; Leg 146; Leg 167; Leg 202; Leg 64; Marine environment; Microfossils; North Pacific; Northeast Pacific; ODP Site 1017; ODP Site 1019; ODP Site 1242; ODP Site 893; Ocean Drilling Program; Oxygen minimum zone; Pacific Ocean; Paleo-oceanography; Paleoclimatology; Paleoenvironment; Pleistocene; Protista; Quaternary; Santa Barbara Basin; Sedimentary structures; Upper Pleistocene
Coordinates: N275406 N275406 W1103921 W1103921
N075100 N075100 W0833600 W0833600
N341715 N343205 W1200211 W1210625
N414058 N414058 W1245559 W1245559
Record ID: 2015081265
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