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Title: TRACKING DEEP-WATER OXYGENATION CHANGES OFFSHORE SOUTHERN CALIFORNIA
Upwelling systems on eastern boundaries of subtropical ocean basins are some of the most climatically dynamic regions of the oceans. Anthropogenic climate change has implications for these marine ecosystems, such as driving marine deoxygenation, driving ecosystem zonation, and driving the expansion of oxygen minimum zones (OMZ). There have been multiple studies evaluating drivers of marine oxygenation changes, yet there is still a need to understand surface processes and source waters influence on bottom-water oxygenation. The California continental margin is a well-studied upwelling system, where source water mixing of oxygen-rich subarctic waters to oxygen-poor subtropical waters is strongly influenced by the California Current, leading to one of the most primary production areas in the Pacific. Here we present data of redox sensitive trace metals to evaluate changes in the bottom water ventilation off the coast of Southern California due to climatic changes. Samples from several sediment cores were recovered via the RV Roger Revelle Expedition RV2206 during the summer of 2022. The sediment samples were digested applying a multi-acid digestion technique and analyzing together with pore water samples via inductively coupled plasma mass spectrometry. Interestingly, we observe a strong flux of specific heavy metals from the sediments into the overlying water column, likely impacting the benthic community and altering the primary metal-proxy signal at these sites with potential implications for the reconstruction of current ventilation through these geochemical and microfossil tracers. Overall, our preliminary results indicate fluctuations in the OMZ seaward expansion with implications for the oxygenation condition of the deeper water.  more » « less
Award ID(s):
1700920
PAR ID:
10487847
Author(s) / Creator(s):
; ; ; ; ;
Corporate Creator(s):
Editor(s):
none.
Publisher / Repository:
Geological Society of America South-Central Section
Date Published:
Journal Name:
Geological Society of America South-Central Section
Edition / Version:
0
Volume:
0
Issue:
0
Page Range / eLocation ID:
0
Subject(s) / Keyword(s):
deep-water oxygenation OMZ sediment geochemistry, Southern California Bight
Format(s):
Medium: X Size: 0 Other: 0
Size(s):
0
Location:
Stillwater, OK
Sponsoring Org:
National Science Foundation
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