Variability of the Late Pleistocene-Early Holocene Oxygen-Minimum Zone off Northern California

  1. David H. Peterson
  1. Roger Y. Anderson1,
  2. James V. Gardner2 and
  3. Eileen Hemphill-Haley2

Published Online: 23 MAR 2013

DOI: 10.1029/GM055p0075

Aspects of Climate Variability in the Pacific and the Western Americas

Aspects of Climate Variability in the Pacific and the Western Americas

How to Cite

Anderson, R. Y., Gardner, J. V. and Hemphill-Haley, E. (1989) Variability of the Late Pleistocene-Early Holocene Oxygen-Minimum Zone off Northern California, in Aspects of Climate Variability in the Pacific and the Western Americas (ed D. H. Peterson), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM055p0075

Author Information

  1. 1

    Department of Geology, University Of New Mexicoalbuquerque, Nm 87131

  2. 2

    U.S. Geological Surveyms-999, Menlo Park, Ca 94025

Publication History

  1. Published Online: 23 MAR 2013
  2. Published Print: 1 JAN 1989

ISBN Information

Print ISBN: 9780875900728

Online ISBN: 9781118664285

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Keywords:

  • Climatic changes—Pacific Area.;
  • Paleoclimatology—Pacific Area.;
  • Climatic changes—West (U.S.);
  • Paleoclimatology—West (U.S.);
  • Atmospheric carbon dioxide.

Summary

Late Pleistocene-Holocene sediments along the upper continental slope off northern California, at water depths between 600 and 1500 m, contain zones of varves that alternate with bioturbated intervals that reflect past variations in the intensity of the oxygen-minimum zone (OMZ). Varves and three types of oxygen-dependent bioturbation are used to derive an OMZ index (OMZI) that quantifies past changes in the OMZ. Major fluctuations are sustained for hundreds of years and represent changes in dissolved oxygenconcentration from near anoxic to fully oxidizing conditions. The spatial distributions of OMZI values along 400 km of the continental slope approximately coincides with the present pattern of upwelling. Past increases in the intensity of the OMZ are most likely correlated to changes in productivity and circulation associated with variability in the wind-stress regime.