California El NiñOs and Related Changes of the California Current System from Recent And Fossil Radiolarian Records

  1. David H. Peterson
  1. Richard E. Casey,
  2. Amy L. Weinheimer and
  3. Carl O. Nelson

Published Online: 23 MAR 2013

DOI: 10.1029/GM055p0085

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

Casey, R. E., Weinheimer, A. L. and Nelson, C. O. (1989) California El NiñOs and Related Changes of the California Current System from Recent And Fossil Radiolarian Records, 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/GM055p0085

Author Information

  1. Marine Studies, University of San Diegoalcala Park, San Diego, Ca 92110

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

Radiolarian data from plankton and modern sediments coupled with physical oceanographic data reveal that California El Niños can be distinguished as “weak” and “strong”. The dynamics of the physical oceanography of each “type” of El Niño determine the radiolarian distribution characteristics in the water column and in the recent sediments below. These “weak” and “strong” types of El Niños can be recognized in the laminated sediments of the anoxic southern California basins. Radiolarian and physical oceanographic evidence also suggest that these “weak” and “strong” California El Niños may be northerly (weak) and southerly (strong) manifestations of a single El Niño event. “Strong” El Niños as opposed to “weak” El Niños are reflected by an increase in the oxygen content of the Santa Barbara Basin waters below sill depth and by a contraction of the oxygen minimum zone in general. Similar oceanographic events (El Niños) and effects (basin oxygénation) can also be recognized in the fossil record. El Niño-like events have been recognized as far north as the Humboldt Basin at least 8 million years ago. El Niño events, such as the modern California El Niños, appear to have been present at least 5.5 million years ago.