Physical Sciences and Mathematics Commons^™

The Nature And Transport Of The Fine-Grained Component Of Swift Creek Landslide, Northwest Washington, Tovah M. (Tovah Michelle) Bayer

WWU Graduate School Collection

Extreme sedimentation in Swift Creek, located in the Cascades foothills in NW Washington (48°55’N, 122°16’W), results from erosion of the oversteepened, unvegetated toe of a large (0.55 km²) active earthflow. The amount of bedload in the creek has necessitated several mitigation projects in the channel including annual dredging and temporary sediment traps in an attempt to reduce the risk of flooding and damage to manmade structures downstream.

The bedload and suspended sediment in the creek are a direct result of the weathering process of the serpentinitic bedrock, in which the landslide is rooted. The serpentinite weathers to asbestiform …