Winter Seismic Soundscape of the Parks Highway Corridor, Central Alaska

Abstract In February 2019, 302 nodal seismometers were deployed every 1 km along the Parks Highway in Alaska, from Nenana to Trapper Creek, for a period of 35 days. Concurrently, 95 seismometers were deployed away from the highway, in a 1.3 km array spanning the Denali fault. The Parks Highway seismometers recorded a variety of signals, including from local, regional, and teleseismic earthquakes, mining blasts, helicopters, planes, trains, and automobiles. Our overarching goal is to characterize the seismic soundscape for this region, composed of source types—defined by durations and frequency ranges—as well as temporal and spatial variations in ambient noise. We present several novel observations for this region, including air-to-ground coupled waves from mining blasts, loaded-versus-unloaded trains, the noise produced by a river frozen at its surface, and the influence of sedimentary basin structures on ambient noise. This documentation of events and noise provides a step toward quantifying the seismic soundscape, establishing distance-based detection limits for different source types, and providing guidance for future detailed studies and deployments in Alaska.