Postdoctoral Fellowship: EAR-PF: Expansion and validation of a robust global seismic debris flow model

Debris flows are destructive, fast-moving mixtures of water, mud, rocks, and other debris that threaten communities, transportation corridors, and critical infrastructure in mountainous regions worldwide. These events often occur in remote and inaccessible terrain, making direct monitoring impractical. This postdoctoral fellowship project will advance the use of environmental seismology for natural-hazard monitoring by developing methods to estimate key debris-flow properties directly from seismic observations. Improved characterization of debris flows will support the national interest by helping scientists better understand how these hazards evolve and will support future efforts to improve hazard assessment and early-warning capabilities. Additionally, the project will support the development of teaching materials on debris flow hazards and the mentoring undergraduate researchers, helping to prepare the next generation of geoscientists. This postdoctoral fellowship project will expand and validate a physics-based mathematical seismic model of debris flows, originally developed for idealized conditions, and adapt it to naturally occurring debris flows in variable, complex channel conditions, as found in natural settings. The research will investigate how variations in grain-size distributions, flow velocity, channel slope, and sediment-bed interactions influence the seismic power generated by debris flows. The project will proceed through three stages: (1) calibration and testing using highly instrumented experiments from the US Geological Survey Experimental Debris-Flow Flume in Oregon, (2) application to well-characterized natural debris flows recorded at Tahoma Creek on Mount Rainier, and (3) generalization of the model using debris flow events compiled in the Exotic Seismic Events Catalog and related global datasets. By integrating seismic observations, geomorphic measurements, and numerical modeling, the postdoctoral fellow will develop a framework to estimate debris flow characteristics from seismic data in settings where direct observations are limited or unavailable. The expected outcomes of this project include improved understanding of the physical controls on debris flow seismic signals and a transferable modeling approach that links seismic observations to debris flow dynamics across various channelized environments. These advances will strengthen the scientific foundation for remote monitoring of hazardous mass movements and contribute to more resilient early warning systems for communities facing natural-hazard risks. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.