Biogeochemical cycling on the seafloor of two California margins

Will Berelson
University of Southern California, Los Angeles

Wednesday, September 2, 1998
3:00 p.m.— Pacific Forum

My research with in situ measurement and seafloor robotics spans the last fifteen years. In that time I have conducted research on nutrient fluxes, biogenic matter remineralization, trace metal, and DOM recycling on many patches of the seafloor—from San Francisco Bay to Moreton Bay (Australia), and from Big Sur to the equatorial Pacific. The questions I ask pertain to understanding the ocean above the seafloor and the sediments below it. My interests are equally divided between understanding modern ocean processes relating to physics, biology, and chemistry and to diagenesis and the paleoceanographic record.

In my presentation, I will introduce you to my efforts at deep-sea robotic engineering and describe the status of my measurement capabilities with some notice of future directions. I will discuss results of a time series of benthic flux measurements made in Monterey Bay between 1991 and 1995 and will compare seafloor measurements made off the central and southern California margins. The discussion will center on the diagenesis of biogenic matter on the seafloor in these regions. Further, central and southern California margins will be compared and contrasted to the equatorial Pacific. One goal of this talk will be to demonstrate how much we have to learn about the ocean by studying the seafloor. A second goal of this talk will be to demonstrate that our current understanding of deep-ocean chemistry and paleoceanographic proxies requires revision, given the results of recent studies of benthic geochemistry.

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