Debris flows are rapidly moving, water-saturated masses of rock and sediment that occur naturally on volcanoes like Mount Adams and Mount Hood. Small, storm-triggered debris flows occur routinely and commonly go unnoticed, but larger storm-triggered debris flows can wreak havoc on anything in their paths before depositing thick layers of rock, sand, and mud on valley floors. In November 2006, Mounts Adams and Hood experienced such debris flows. Far larger debris flows, the result of volcanic eruptions or large landslides, have occurred prehistorically on Mount Adams and Hood and have inundated the landscape along the entire lengths of the White Salmon and Hood Rivers. Join Richard Iverson, scientist emeritus at the U.S. Geological Survey’s Cascades Volcano Observatory, for a look at how scientists assess the what, where, how, and why of big debris flows and find out why it’s still so challenging to foretell when the next one will occur.
Richard (Dick) Iverson spent 34 years as a research scientist at the U.S. Geological Survey’s Cascades Volcano Observatory in Vancouver, Washington, and he remains affiliated with the observatory as a scientist emeritus. His work there has focused mostly on the dynamics of landslides and debris flows, with particular emphasis on evaluating hazards downstream from Cascades volcanoes. Iverson grew up in Iowa, received his Ph.D. from Stanford University, and moved from Vancouver to Hood River in 2018.