Analyzing seismic data recorded from a debris flow at Mount Rainier National Park

Debris flows are some of the most dangerous volcanic hazards and may occur at any time, even during periods of volcanic rest. Often called lahars at volcanoes, debris flows are water-saturated landslides that move rapidly and can travel large distances. Debris flows often occur in remote locations and are difficult to predict, making it challenging to study and collect data on the events. Efforts are being made to collect data with instruments such as seismometers to better understand debris flow dynamics, estimate hazard, and provide warning when communities are threatened. Tahoma Creek, a stream on the southwestern slopes of Mount Rainier, is prone to small debris flows and provides an excellent location to study flow processes. We deployed monitoring equipment including temporary seismometers along Tahoma Creek drainage and recorded a small debris flow on 15 August 2023. We plan to use the collected data to model the debris flow and attempt to link the data to properties of the event, such as velocity or volume. The ability to interpret aspects of a debris flow from recorded seismic data would allow warning systems to better inform threatened communities about the hazard represented by individual events.

Avery Conner
University of Oregon

Presentation given at North Coast & Cascades Science Days, 2024
go.nps.gov/sciencedays
[MORA]