Please use this identifier to cite or link to this item: http://hdl.handle.net/1893/17619
Appears in Collections:Biological and Environmental Sciences Journal Articles
Peer Review Status: Refereed
Title: Mid-Holocene strengthening of the Southern westerlies in South America - Sedimentological evidences from Lago Cardiel, Argentina (49 degrees S)
Authors: Gilli, Adrian
Ariztegui, Daniel
Anselmetti, Flavio
McKenzie, Judith
Markgraf, Vera
Hajdas, Irka
McCulloch, Robert
Contact Email: robert.mcculloch@stir.ac.uk
Keywords: closed lake basin
magnetic susceptibility
wind intensity
Southern Westerlies
paleoclimate
Patagonia
Issue Date: Nov-2005
Publisher: Elsevier
Citation: Gilli A, Ariztegui D, Anselmetti F, McKenzie J, Markgraf V, Hajdas I & McCulloch R (2005) Mid-Holocene strengthening of the Southern westerlies in South America - Sedimentological evidences from Lago Cardiel, Argentina (49 degrees S), Global and Planetary Change, 49 (1-2), pp. 75-93.
Abstract: The paleoclimatic evolution of southern South America is characterized to a large extent by the behavior (strength and latitudinal position) of the storm tracks of the Southern Westerlies. Our study site, Lago Cardiel (49oS), lies within the modern influence of the Southern Westerlies and, therefore, is ideally located to track the past migrations of these storm tracks. With a coring strategy taking into account the lateral differences in sedimentation and an excellent core-to-core correlation using tephra layers, a composite sedimentological record of almost 25 m was established covering the last ~16,000 cal yr. Sedimentological and petrophysical analysis of the cores revealed the establishment of a dominant lake current since 6800 cal yr BP leading to a drift deposition, which is especially well-expressed in the sedimentary record by an increase in magnetic susceptibility values. As this pattern of currents is most likely induced by wind activity, we propose that the observed increase in magnetic susceptibility documents an intensification of the westerly storm tracks. This intensification occurred slightly earlier than previously suggested based on palynological evidence. The strengthening in the Southern Westerlies during the mid-Holocene is most likely caused by an increase in the temperature gradient as a result of enhanced influence and/or southward migration of the Southeast Pacific anticyclone and a larger Antarctic sea-ice extent.
Type: Journal Article
URI: http://hdl.handle.net/1893/17619
DOI Link: http://dx.doi.org/10.1016/j.gloplacha.2005.05.004
Rights: The publisher does not allow this work to be made publicly available in this Repository. Please use the Request a Copy feature at the foot of the Repository record to request a copy directly from the author. You can only request a copy if you wish to use this work for your own research or private study.
Affiliation: ETH Zurich
ETH Zurich
ETH Zurich
ETH Zurich
University of Colorado
ETH Zurich
Biological and Environmental Sciences

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