Climate on the Blanca Massif, Sangre De Cristo Mountains, Colorado, USA, During the Last Glacial Maximum
quaternary Article Climate on the Blanca Massif, Sangre de Cristo Mountains, Colorado, USA, during the Last Glacial Maximum Keith A. Brugger 1,* , Eric M. Leonard 2, Kurt A. Refsnider 3 and Peter Dolan 4 1 Geology Discipline, University of Minnesota, Morris, MN 56267, USA 2 Department of Geology, Colorado College, Colorado Springs, CO 80903, USA; eleonard@coloradocollege.edu 3 101 W Goodwin St #3849, Prescott, AZ 86302, USA; kurt.refsnider@gmail.com 4 Statistics and Computer Science Disciplines, University of Minnesota, Morris, MN 56267, USA; dolan118@morris.umn.edu * Correspondence: bruggeka@morris.umn.edu Abstract: Temperature-index modeling is used to determine the magnitude of temperature de- pression on the Blanca Massif, Colorado, required to maintain steady-state mass balances of nine reconstructed glaciers at their extent during the Last Glacial Maximum (LGM). The mean temperature depression thus determined is ~8.6 +0.7/−0.9 ◦C where the uncertainties account for those inherent in the glacier reconstructions, in model parameters (e.g., melt factors), and possible modest changes in LGM precipitation. Associated equilibrium-line altitudes (ELAs) exhibit a statistically significant directional dependency being lower toward the north and east. Under the assumption that regional temperature change was uniform, required changes in precipitation vary systematically—also exhibit- ing a directional dependency coinciding with that in ELAs—and indicate increases (over modern) occurred on the eastern side of the massif while decreases occurred on the western side. This disparity represents a strengthening of a precipitation asymmetry, particularly winter precipitation, which Citation: Brugger, K.A.; Leonard, E.M.; Refsnider, K.A.; Dolan, P.
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