Forecasting and seismic detection of debris flows at Mount Rainier National Park

Debris flows occur as a result of glacial outburst floods or intense fall storms prior to snow accumulations and occur commonly at the glaciated Mount Rainier, WA. Over 60 such events have been documented since 1928, 35+ of which have occurred in Tahoma Creek on the southwest side of the park.

A well-documented debris flow in 2015 showed that visitors were in areas immediately adjacent to a debris flow that could have been detected two hours prior. Since that time, the park has developed

1. A quantitative daily forecast for debris-flow hazards;
2. A real-time debris-flow detection algorithm utilizing pattern analysis of seismic spectra on four seismographs on the south and southwest side of Mount Rainier National Park.

The algorithm successfully detected a debris flow in Tahoma Creek on August 15, 2023. The goal of this system is to provide advance warning of debris-flow conditions several days prior to the event and then detect debris-flow events in real-time so that visitors and employees can be evacuated from areas downstream of the debris flows.