Abstract

Oxygen minimum zones (OMZs), located below highly productive marine regions, are sites of microbially-mediated denitrification and biogeochemical cycling that have global significance. The intensity of OMZs fluctuate naturally, however, the degree to which they fluctuate and a comprehensive understanding of the factors that drive these fluctuations on interannual to centennial time scales is lacking. A high-resolution (near annual) record of δ15Nsed from the Pescadero Slope in the Gulf of California (eastern tropical north Pacific, ETNP) suggests that the OMZ is self-regulating, capped by maximum (10.5‰) and minimum (8.0‰) δ15Nsed values which create hard ceilings and floors between which OMZ intensity has varied over the past 1200 years. A comparative analysis of the relationship between δ15NO3-and [O2] in Pescadero and nearby sites suggests the observed range of δ15Nsed values is equivalent to …

Date

2016

Authors

Caitlin Tems, William Berelson, Robert Thunell, Xiaomei Xu, Deborah Khider

Journal

American Geophysical Union, Ocean Sciences Meeting

Volume

2016

Pages

PC51A-03