Adam R. Mosbrucker Kurt R. Spicer Charles Crisafulli V. Dale Jon J. Major 2018 <p><span>Exceptional sediment yields persist in Toutle River valley more than 30&nbsp;years after the major 1980 eruption of Mount St. Helens. Differencing of decadal-scale digital elevation models shows the elevated load comes largely from persistent lateral channel erosion across the debris-avalanche deposit. Since the mid-1980s, rates of channel-bed-elevation change have diminished, and magnitudes of lateral erosion have outpaced those of channel incision. A digital elevation model of difference from 1999 to 2009 shows erosion across the debris-avalanche deposit is more spatially distributed compared to a model from 1987 to 1999, in which erosion was strongly focused along specific reaches of the channel.</span></p> application/pdf 10.1007/978-1-4939-7451-1_2 en Springer Sediment erosion and delivery from Toutle River basin after the 1980 eruption of Mount St. Helens: A 30-year perspective chapter