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dc.contributor.advisor Heermance, Richard V. en
dc.contributor.author Graham, Joshua Tate en
dc.date.accessioned 2014-01-02T16:28:18Z en
dc.date.available 2014-01-02T16:28:18Z en
dc.date.copyright 2013 en
dc.date.issued 2014-01-02 en
dc.date.submitted 2013-12 en
dc.identifier.uri http://hdl.handle.net/10211.2/4849 en
dc.description Includes bibliographical references (pages 58-65) en
dc.description California State University, Northridge. Department of Geological Sciences. en
dc.description.abstract The well‐preserved moraines in the cirque at the head of Grizzly Creek, Klamath Mountains, California, provide the most complete record of late‐Holocene glacier fluctuations yet documented in this region. Two separate moraine complexes lie below the modern glacier, within the cirque, only one of which supports substantial tree growth. 10Be cosmogenic ages of scoured bedrock surfaces and moraine boulders, as well as tree‐ring ages indicate the approximate timing of glacial maxima in the Grizzly Valley cirque. The combination of the detailed climate record, provided by tree‐ring widths, and the estimated moraine ages, determined from dendrochronology and cosmogenic dating, allows for an accurate reconstruction of the Grizzly Valley Glacier fluctuations over the last 1,000 years. Nine new cosmogenic exposure ages, combined with dendrochronology, constrain the timing of glacier maxima to ~690, ~150 and ~130 years before present (ybp). Around 690 ybp, the equilibrium‐line altitude (ELA) was depressed ~160 meters relative to the ELA of the modern glacier. Using local temperature and precipitation lapse rates and the elevation of the contemporary glacier, we found that in comparison with modern climate conditions, the mean summer temperature during the ~690 ybp glacier maximum was ~0.9°C less and winter precipitation was ~95 cm in snow water equivalent (SWE) greater. During the -150 and ~130 ybp glacier maxima, the ELA was ~67 meters lower than the modern ELA. The mean summer temperature corresponding to this glacier maximum was ~0.4°C cooler and winter precipitation was ~44 cm greater in comparison with modern climate. The climate regime over the last 1,000 years in the Klamath Mountain region seems to be cool and exceptionally wet. The ~690 ybp glacier maximum in the Klamath Mountains is not apparent in the Sierra Nevada or Cascade Ranges. Also, glaciers in the Sierra Nevada and Cascade Ranges retreated from their most recent LIA maxima ~20-30 years before the glaciers of the equivalent advance in the Klamath Mountains. The climate in the Klamath Mountains likely varies from the Sierra Nevada and Cascade ranges due to the proximity to the Pacific Ocean. The chronology of Grizzly Valley Glacier fluctuations, determined in this study, suggests that in California the regional response to large‐scale climate regimes can vary over relatively short lateral distances. en
dc.description.statementofresponsibility by Joshua Tate Graham en
dc.format application/pdf en
dc.format.extent x, 124 pages en
dc.language.iso en en
dc.publisher California State University, Northridge en
dc.rights.uri http://scholarworks.csun.edu/xmlui/handle/10211.2/286 en
dc.subject Climate change en
dc.subject Climate fluctuations en
dc.subject Moraines en
dc.subject Cosmogenic exposure dating en
dc.subject Dendrochronology en
dc.subject Little Ice Age en
dc.subject Holocene en
dc.subject climate en
dc.subject Klamath Mountains en
dc.subject Glaciers en
dc.subject.other Dissertations, Academic -- CSUN -- Geology. en
dc.title Late Holocene glacial advances in the Klamath Mountains, northern California, determined from 10Be cosmogenic exposure dating and dendrochronology en
dc.type Thesis en
dc.date.updated 2014-01-02T16:28:20Z en
dc.contributor.department Geological Sciences en
dc.description.degree M.S. en
dc.contributor.committeemember Laity, Julie E. en
dc.contributor.committeemember Yule, John D. en
dc.contributor.committeemember Hayes, James en
dc.rights.license By signing and submitting this license, you the author grant permission to CSUN Graduate Studies to submit your thesis or dissertation, and any additional associated files you provide, to CSUN ScholarWorks, the institutional repository of the California State University, Northridge, on your behalf. You grant to CSUN ScholarWorks the non-exclusive right to reproduce and/or distribute your submission worldwide in electronic or any medium for non-commercial, academic purposes. You agree that CSUN ScholarWorks may, without changing the content, translate the submission to any medium or format, as well as keep more than one copy, for the purposes of security, backup and preservation. You represent that the submission is your original work, and that you have the right to grant the rights contained in this license. You also represent that your submission does not, to the best of your knowledge, infringe upon anyone's copyright. If the submission contains material for which you do not hold copyright, or for which the intended use is not permitted, or which does not reasonably fall under the guidelines of fair use, you represent that you have obtained the unrestricted permission of the copyright owner to grant CSUN ScholarWorks the rights required by this license, and that such third-party owned material is clearly identified and acknowledged within the text or content of the submission. If the submission is based upon work that has been sponsored or supported by an agency or organization other than the California State University, Northridge, you represent that you have fulfilled any right of review or other obligations required by such contract or agreement. CSUN ScholarWorks will clearly identify your name(s) as the author(s) or owner(s) of the submission, and will not make any alterations, other than those allowed by this license, to your submission. en


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