Figure 1 (IMAGE)
Caption
The March 22, 2014 SR530 landslide near Oso, Washington, caused 43 fatalities, destroyed a neighborhood, blocked a state highway, and temporarily dammed the North Fork Stillaguamish River. This photo was taken the day after the catastrophic slide, before the river cut through the landslide deposit. Here, several geomorphological components of the landslide are visible, with a hummock field in the foreground transitioning upslope to larger slices of deposit separated by multiple scarps, which then transition to a fallen-tree covered, back-rotated block downdropped from the headscarp in the far field. Nearly the entire landslide deposit exhibits indications of extension. Collins and Reid attribute extensional hummock formation to widespread basal liquefaction of underlying alluvial sediments in the river valley. Photo by Stephen Slaughter (Washington Geological Survey, Washington Department of Natural Resources).
Credit
Stephen Slaughter (Washington Geological Survey, Washington Department of Natural Resources)
Usage Restrictions
Stephen Slaughter (Washington Geological Survey, Washington Department of Natural Resources)
License
Licensed content