LINKING JOKULHLAUPS WITH KETTLES AND THE STEILACOOM GRAVEL

The study area is located in the vicinity of Puyallup, WA, 35 miles south of Seattle. Terraced fluvial channels cut through cobbles and pebbles; several lakes are found to the southwest of the channels. Wide spread deposits of clean cobbles, pebbles, and sand were the initial interest in the area and are thought to be of flood deposition. To investigate the topography and geologic units construction borehole data was entered into a GIS database for spatial analysis and cross section construction. Small subglacial outburst floods, jokulhlaups, have been observed in Alaska while large events occur in Iceland due to basal heating by volcanism and create deposits consistent with those mapped in the Puget Sound region. A series of flooding events, kettle creation, and Puget Sound Ice Lobe kinematics and dynamics are proposed.