Tree Throws, Spodosols, and Sand Flows: Analyzing Sand Flow Slides and Their Triggers , Haines, Alaska

ABSTRACT The Lutak Spur (LS) is a prominent deltaic landform near Haines, Alaska, formed during the retreat of the Cordilleran Ice Sheet from the Last Glacial Maximum. This study evaluates its geologic evolution, soil development, and slope stability response to a December 2020 atmospheric river (AR) event that triggered multiple landslides. We posit that LS formed as an ice-contact kame delta at the margin of a retreating valley glacier. Post-glacial isostatic rebound exposed the LS surface, al