Forecasting and Seismic Detection of Proglacial Debris Flows at Mount Rainier National Park, Washington, USA

Abstract

The glaciated Mount Rainier volcano in southwestern Washington State (United States) has a rich history of outburst floods and debris flows that have adversely impacted infrastructure at Mount Rainier National Park in the 20th and 21st centuries. Retreating glaciers leave behind vast amounts of unconsolidated till that is easily mobilized during high-precipitation-intensity storms in the fall months, and during outburst floods during warm summer months. Over 60 debris flows and outburst floods have been documented between 1926 and 2019 at Mount Rainier. Debris-flow activity has led to the closure of campgrounds and visitor destinations, which has limited visitor access to large swaths of the park. This paper documents efforts to characterize and seismically monitor debris flows, map hazards, and develop forecasting approaches for wet and dry weather debris flows. Using the day-of and historic antecedent weather conditions on past debris-flow days, we developed a debris-flow hazard model to help predict those days with a higher relative hazard for debris-flow activity park-wide based on prevailing and forecasted weather conditions. Debris flows are detected in near-real-time using the U.S. Geological Survey Real-time Seismic Amplitude Measurement (RSAM) tool. If an event is detected, we can then provide evacuation alerts to employees and visitors working and recreating in the areas downstream. Our goal is to accurately forecast the debris-flow hazards up to 7 days ahead of time and then use RSAM to detect debris flows within minutes of their genesis.

Quantifying sediment connectivity: Moving toward a holistic assessment through a mixed methods approach

“…Events causing rapid geomorphic change continue to occur as glaciers retreat and the landscape adjusts to present conditions. Historical records, while incomplete, indicate that at least 33 debris flow events originating at or near the South Tahoma Glacier terminus have occurred since 1967 (Beason et al, 2019; Crandell, 1971; Legg et al, 2014; Richardson, 1968; Walder & Driedger, 1994a, 1994b). Additionally, four debris flows have been recorded 8.5 km below the glacier originating from Dry Creek.…”

Spatial Patterns of Disconnectivity Explain Catchment‐Scale Sediment Dynamics and Transfer Efficiencies

“…Beason et al. (2019) describe the debris flow hazard model used at Mount Rainier to forecast both dry and wet weather debris flows with some success.…”

“…Today, the Tahoma Creek watershed is prone to frequent non‐cohesive debris flows, typically on the order of 10 4 –10 5 m 3 in volume, that enact rapid geomorphic change (Walder & Driedger, 1994b). At least 35 debris flow events have occurred since 1967 (Beason et al., 2019; Crandell, 1971; Legg et al., 2014; Richardson, 1968; Walder & Driedger, 1994a, 1994b). These events often originate as glacial outburst floods or failure of proglacial gully walls during hydrological events (Legg et al., 2014; Walder & Driedger, 1994b).…”

“…These events often originate as glacial outburst floods or failure of proglacial gully walls during hydrological events (Legg et al, 2014;Walder & Driedger, 1994b). Beason et al (2019) describe the debris flow hazard model used at Mount Rainier to forecast both dry and wet weather debris flows with some success.…”

Inventory of glaciers and perennial snowfields of the coterminous USA

“…">IntroductionGlaciers are an important feature of the landscape for several reasons. Geologically, they modify the landscape through erosion and deposition (Alley et al, 2019;Benn & Evans, 2010).Although these processes are typically slow, sudden episodes can occur such as moraine failure due to fluvial erosion resulting in catastrophic debris flows (Beason et al, 2018;Chiarle et al, 2007;O'Connor et al, 2001). Hydrologically, glaciers can be viewed as frozen reservoirs of water that naturally regulate streamflow on seasonal to decadal time scales (Dussaillant et al, 2019;Fountain & Tangborn, 1985; Moore et al, 2009).…”