Rapid Refreezing of a Marginal Ice Zone Across a Seafloor Distributed Acoustic Sensor

Abstract

Seismic instruments such as broadband seismometers and distributed acoustic sensors (DAS) have a demonstrated potential for wide-scale and continuous in situ monitoring of near-surface environmental and anthropogenic processes. DAS is attractive for development as a multi-geophysical observatory due to the prevalence of existing fiber infrastructure in regions with environmental, cultural, or strategic significance. Here we present results from a multi-seasonal acquisition of DAS data on a seafloor cable in the Beaufort Sea, Alaska. During a November 2021 data collect we captured the rapid transition of ambient noise characteristics from an “ice-free” state to an “ice-bound” state. A sea ice formation front was plainly visible on the DAS record and was observed to propagate 20 km seaward over a period of 8 hr. Satellite-based instrumentation were unable to record this event due to cloud cover, low light conditions, and orbital frequency.