Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.
Collapse of the California Current During Glacial Maxima Linked to Climate Change on Land
T. D. Herbert,1*J. D. Schuffert,1D. Andreasen,2L. Heusser,3M. Lyle,4A. Mix,5A. C. Ravelo,2L. D. Stott,6J. C. Herguera7
Time series of alkenone unsaturation indices gathered along the
California margin reveal large (4° to 8°C) glacial-interglacialchanges in sea surface temperature (SST) over the past 550,000years. Interglacial times with SSTs equal to or exceeding thatof the
Holocene contain peak abundances in the pollen of redwood,the
distinctive component of the temperate rainforest of the northwestcoast of California. In the region now dominated by the CaliforniaCurrent, SSTs warmed 10,000 to 15,000 years in advance of deglaciationat each of the past five glacial maxima. SSTs did not rise inadvance
of deglaciation south of the modern California Currentfront. Glacial
warming along the California margin therefore isa regional signal of
the weakening of the California Current duringtimes when large ice
sheets reorganized wind systems over theNorth Pacific. Both the timing
and magnitude of the SST estimatessuggest that the Devils Hole
(Nevada) calcite record representsregional but not global
paleotemperatures, and hence does notpose a fundamental challenge to
the orbital ("Milankovitch") theoryof the Ice Ages.
1 Department of Geological Sciences, Brown
University, Providence, RI 02912, USA.
2 University
of California, Santa Cruz, CA 95064, USA.
3 Lamont-Doherty Earth Observatory, Palisades, NY
10964, USA.
4 Center for Geophysical Investigation
of the Shallow Subsurface, Boise State University, Boise, ID 83725, USA.
5 Oregon State University, Corvallis, OR 97331, USA.
6 University of Southern California, Los
Angeles, CA 90089, USA.
7 Centro de
Investigación Científica y de Educación Superior de
Ensenada, Ensenada 22860, Mexico.
*
To whom correspondence should be addressed.
The editors suggest the following Related Resources on Science sites:
In Science Magazine
PERSPECTIVES
David W. Lea (6 July 2001) Science293 (5527), 59.
[DOI: 10.1126/science.1061078] |Summary »|Full Text »
THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Eelgrass Meadows in the California Channel Islands and Adjacent Coast Reveal a Mosaic of Two Species, Evidence for Introgression and Variable Clonality.
J. A. Coyer, K. A. Miller, J. M. Engle, J. Veldsink, A. Cabello-Pasini, W. T. Stam, and J. L. Olsen (2008)
Ann. Bot.
101, 73-87
|Abstract »|Full Text »|PDF »
Diversification Before the Most Recent Glaciation in Balanus glandula.
Structure of the penultimate deglaciation along the California margin and implications for Milankovitch theory.
(2005)
Geology
33, 157-160
Carbon starvation in glacial trees recovered from the La Brea tar pits, southern California.
J. K. Ward, J. M. Harris, T. E. Cerling, A. Wiedenhoeft, M. J. Lott, M.-D. Dearing, J. B. Coltrain, and J. R. Ehleringer (2005)
PNAS
102, 690-694
|Abstract »|Full Text »|PDF »
Assessing the Causes of Late Pleistocene Extinctions on the Continents.
A. D. Barnosky, P. L. Koch, R. S. Feranec, S. L. Wing, and A. B. Shabel (2004)
Science
306, 70-75
|Abstract »|Full Text »|PDF »
The last interglacial period on the Pacific Coast of North America: Timing and paleoclimate.
D. R. Muhs, K. R. Simmons, G. L. Kennedy, and T. K. Rockwell (2002)
GSA Bulletin
114, 569-592
|Abstract »|Full Text »|PDF »
The California Current, Devils Hole, and Pleistocene Climate.
I. J. Winograd, T. D. Herbert, J. D. Schuffert, D. Andreasen, L. Heusser, M. Lyle, A. Mix, A. C. Ravelo, L. D. Stott, and J. C. Herguera (2002)
Science
296, 7a
|Full Text »|PDF »
Direct Determination of the Timing of Sea Level Change During Termination II.
C. D. Gallup, H. Cheng, F. W. Taylor, and R. L. Edwards (2002)
Science
295, 310-313
|Abstract »|Full Text »|PDF »
Interglacial theme and variations: 500 k.y. of orbital forcing and associated responses from the terrestrial and marine biosphere, U.S. Pacific Northwest.
