16 Understanding the Past and Present Cryosphere of the Rocky Mountains

Alpine snow and ice play seminal roles in the environmental, geomorphic, and hydrologic processes. This session welcomes abstracts on scientific studies of the past and present cryosphere in the Rocky Mountains and beyond.

Monday, 18 May 2026
3:00 PM - 5:30 PM
Alvarado C

Last Glacial Maximum Climate in the Southern Rocky Mountains: A Chillier LGM in the Region?

Paper number: 16-5
Program: Technical Sessions
Time: 4:40 PM – 5:00 PM

Authors

Abstract

Reconstruction of paleoglaciers in the southern Sangre de Cristo Mountains (Colorado and New Mexico), Latir Peak (New Mexico), and San Francisco Mountain (Arizona) formed the basis of temperature-index (TI) modeling to estimate the magnitude of regional temperature change during the Last Glacial Maximum (LGM) in the Southern Rocky Mountains. TI models are used to determine temperatures and precipitation that would maintain steady-state mass balance of glaciers at their maximum LGM extents. If precipitation was similar to that today, modeling suggests that LGM mean annual temperatures were between ~8.5 and 10.5 °C. Uncertainties, largely dependent on parameters used in the models and assumptions regarding possible changes in LGM precipitation, are on the order of ±1 °C. Thus the magnitude of regional temperature depression appears to be comparable to, or greater than, those similarly derived for the Middle and Northern Rocky Mountains. These results are somewhat in conflict with other studies that indicate estimates of temperature depressions in the Southern Rocky Mountains were of lesser magnitude. Moreover, they stand in contrast with climate models that suggest a general trend of a southward decrease of LGM cooling along the Rocky Mountains. These disparities might, however, be mitigated by several uncertainties, especially those in LGM precipitation. Nevertheless, the individual estimates of temperature depression presented here are consistent with regional-scale climate models as well as high-resolution downscaling of global LGM climate for their respective locations.

Geological Society of America Abstracts with Programs. Vol. 58, No. 4

doi: 10.1130/abs/2026RM-410577

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