Latest Pleistocene to Holocene hydroclimates from Lake Elsinore, California Kirby, M.E.; Feakins, S.J.; Bonuso, N.; Fantozzi, J.M.; Hiner, C.A. Kirby, M.E. Feakins, S.J. Bonuso, N. Fantozzi, J.M. Hiner, C.A. Younger Dryas hydrology earth science/paleoclimate/paleolimnology (mass magnetic susceptibility,sediment,null,cubic meter per kilogram,null,paleolimnology,null,null,N,x10-7 units) earth science/paleoclimate/paleolimnology (clay,sediment,null,percent,null,paleolimnology,null,laser particle size analysis,N,null) earth science/paleoclimate/paleolimnology (depth,null,null,centimeter,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (sand,sediment,null,percent,null,paleolimnology,null,laser particle size analysis,N,null) earth science/paleoclimate/paleolimnology (delta 2H,C28 n-alkanoic acid,null,per mil VSMOW,null,paleolimnology,averaged,null,N,null) earth science/paleoclimate/paleolimnology (delta 2H,C28 n-alkanoic acid,one standard deviation,per mil VSMOW,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (organic matter,sediment,null,percent,null,paleolimnology,null,loss on ignition,N,loss on ignition at 550 degrees C) earth science/paleoclimate/paleolimnology (silt,sediment,null,percent,null,paleolimnology,null,laser particle size analysis,N,null) earth science/paleoclimate/paleolimnology (carbonate,sediment,null,percent,null,paleolimnology,null,loss on ignition,N,loss on ignition at 950 degrees C) earth science/paleoclimate/paleolimnology (carbon/nitrogen,sediment,null,dimensionless,null,paleolimnology,null,elemental analysis,N,total organic carbon/total nitrogen) earth science/paleoclimate/paleolimnology (age,null,null,calendar year before present,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology earth science/paleoclimate/paleolimnology earth science/paleoclimate/paleolimnology (Lake Elsinore>LATITUDE 33.6733>LONGITUDE -117.3542) The hydroclimate of the southwestern United States (US) region changed abruptly during the latest Pleistocene as the continental ice sheets over North America retreated from their most southerly extent. To investigate the nature of this change, we present a new record from Lake Elsinore, located 36 km inland from the Pacific Ocean in Southern California and evaluate it in the context of records across the coastal and interior southwest United States, including northwest Mexico. The sediment core recovered from Lake Elsinore provides a continuous sequence with multi-decadal resolution spanning 19e9 ka BP. Sedimentological and geochemical analyses reveal hydrologic variability. In particular, sand and carbonate components indicate abrupt changes at the Oldest Dryas (OD), BøllingeAllerød (BA), and Younger Dryas (YD) transitions, consistent with the timing in Greenland. Hydrogen isotope analyses of the C28 nalkanoic acids from plant leaf waxes (dDwax) reveal a long term trend toward less negative values across 19-9 ka BP. dDwax values during the OD suggest a North Pacific moisture source for precipitation, consistent with the dipping westerlies hypothesis. We find no isotopic evidence for the North American Monsoon reaching as far west as Lake Elsinore; therefore, we infer that wet/dry changes in the coastal southwest were expressed through winter-season precipitation, consistent with modern climatology. Comparing Lake Elsinore to other southwest records (notably Cave of Bells and Fort Stanton) we find coincident timing of the major transitions (OD to BA, BA to YD) and hydrologic responses during the OD and BA. The hydrologic response, however, varied during the YD consistent with a dipole between the coastal and interior southwest. The coherent pattern of hydrologic responses across the interior southwest US and northwest Mexico during the OD (wet), the BA (drier), and YD (wet) follows changes in the Atlantic Meridional Overturning Circulation, presumably via its combined influence on North Pacific winter storm tracks and the extent/magnitude of the North American Monsoon. In contrast, Lake Elsinore and the coastal southwest experiences a deglacial drying trend punctuated by abrupt change at the OD to BA and BA to YD transitions. This trend tracks rising greenhouse gases through the deglacial, with an apparent southward shift in westerly moisture sources adjusting to the retreating ice sheet. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Kirby, M.E. Investigator : Feakins, S.J. Investigator : Bonuso, N. Investigator : Fantozzi, J.M. Investigator : Hiner, C.A. 2013-05-22 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/15934 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/california/elsinore2013sediment.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/california/elsinore2013isotope.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/california/elsinore2013sediment.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/california/elsinore2013isotope.txt English https://www.ncdc.noaa.gov/paleo/study/15934 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/california/elsinore2013sediment.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/california/elsinore2013isotope.txt Matthew E. Kirby, Sarah J. Feakins, Nicole Bonuso, Joanna M. Fantozzi, Christine A. Hiner2013Latest Pleistocene to Holocene hydroclimates from Lake Elsinore, CaliforniaQuaternary Science Reviews761-15http://dx.doi.org/10.1016/j.quascirev.2013.05.023 START YEAR: 18695 cal yr BP * END YEAR: 9228 cal yr BP -117.3542 33.6733 -117.3542 33.6733