GLACIAL GEOLOGIC MAPPING AND RETREAT RATES AT MOUNT RAINIER, WASHINGTON

Mount Rainier is a glaciated peak in the Central Cascade Mountain Range with 25 major glaciers that provide water and hydropower to areas in western Washington. We use published glacial geologic studies, field mapping, and satellite imagery to locate moraine sequences deposited by Carbon, Emmons, Inter, Nisqually, Tahoma, and Williwakas Glaciers. Published studies of glacial retreat on Mount Rainier identify late-Holocene moraine chronologies, and calculate decadal retreat using remote sensing. We enhance and integrate existing work by (1) interpreting and digitizing published moraine locations, and (2) mapping more recent recessional moraines with high-precision GPS. Satellite imagery and computer-based mapping will aid in the mapping of inaccessible locations. Past studies suggest an accelerated rate of ice loss in some valleys, while retreat in other valleys may be slowed by debris cover due to rockfall. This study will provide improved glacial retreat chronologies by combining mapped moraine sequences and remote sensing analysis to compare retreat rates across multiple time scales.