摘要：Nineteen former valley glaciers were reconstructed for their Last Glacial Maximum (LGM) extents in the northern Uinta Mountains, Utah, U.S.A. Mean equilibrium-line altitudes (ELAs) calculated by four methods (accumulation–area ratio, toe–headwall altitude ratio, lateral moraines and cirque floors) range from 3050 to 3300 m a.s.l. Modern mean summer temperatures ( T s) at the ELAs range from 8.7° to 11.2°C, while modern winter precipitation ( P ) ranges from 354 to 590 mm snow water equivalent (SWE). Based on the difference in elevation of mean ELAs across the range, LGM P values must have ranged from 940 to 3040 mm SWE, assuming the modern summer lapse rate was the same during the LGM. A T s depression of 5.5°C is required for these precipitation values to plot in the range of modern ELA values. The reconstructed increase in P at the western end of the range is 10 times the modern increase, reflecting the influence of pluvial Lake Bonneville. Assuming ELA depression (ΔELA) resulted from this P increase and a uniform 5.5°C T s decrease, the regional LGM ΔELA was approximately 900 m.
