Seismic Monitoring of Post-wildfire Debris Flows Following the 2019 Museum Fire, Arizona

Ryan Porter,Abraham E. Springer,John Spruell,Joseph Loverich,Taylor Joyal,Peter R. Robichaud,Aubrey LaPlante,Edward Schenk,Rebecca Beers,Ann Youberg

doi:10.3389/feart.2021.649938

Abstract

Seismic Monitoring of Post-wildfire Debris Flows Following the 2019 Museum Fire, Arizona

Highlights

The 2019 Museum Fire burned ∼8 km2 of ponderosa pine and mixed-conifer forests in mountainous terrain ∼2 km north of Flagstaff, Arizona, USA (Figure 1)
While the immediate threats posed by wildfire are substantial, another concern is often the post-wildfire debris flows caused by the removal of vegetation and ground cover, and creation of water repellent soil conditions following fire (e.g., Neary et al, 2012)
We present seismic data recorded by this network and additional rainfall and photographic data. These data provide a tool for examining post-wildfire debris flows in the southwestern US

Summary

INTRODUCTION

The 2019 Museum Fire burned ∼8 km of ponderosa pine and mixed-conifer forests in mountainous terrain ∼2 km north of Flagstaff, Arizona, USA (Figure 1). Following the Museum Fire, a small network of seismometers was deployed during the summers and falls of 2019 and 2020 The purpose of this network was to record seismic signals associated with debris flows that occurred within and downstream of the burn area. In northern Arizona, precipitation is concentrated in the winter as snowfall and late summer months as high-intensity monsoonal rain storms (July–September) (Jurwitz, 1953) These high-intensity monsoonal storms have a high probability to produce flooding and debris flows when they occur within recently burned areas in steep terrain. In addition to the seismic observations, other data types collected include precipitation measurements, downstream discharge, photo monitoring of debris flows, and hillslope infiltration measurements These data can be used in conjunction with seismic data in order to better calibrate the seismic observations allowing for accurate determination of debris flow magnitude, velocity, and grain size distribution. We present data from one major rainfall events and demonstrate some of the type of analyses useful for debris flow characterization

METHODS

SUMMARY STATEMENT

DATA AVAILABILITY STATEMENT