Sea Ice and the Alaska Transportable Array

Date: 4/26/2019

Time: 06:00 PM

Room: Grand Ballroom

The northern coastal seismic stations of the National Science Foundation sponsored EarthScope Alaska Transportable Array are well-positioned to record the seasonal changes in microseism due to the formation and break-up of sea ice. We examine the correlation between noise levels around the 1 Hz frequency band at these stations and sea ice concentration. Power spectral densities and noise spectrograms are requested from the IRIS DMC MUSTANG metric service and sea ice concentrations measurements are obtained from the National Snow and Ice Data Center. Formation of continuous sea ice corresponds to a significant drop in noise at coastal stations, up to a ~25 dB decrease in less than 24 hours. This drop in noise amplitude coincides with the formation of near-shore ice locally, with station A36M exhibiting an earlier drop in noise than A19K which is further to the southwest where sea ice forms later in the season. We can use data from multiple stations recording multiple cycles of sea ice formation and breakup to build on previous investigations both in the Arctic (Tsai and McNamara, 2011) and in the Antarctic (Anthony et al., 2017). Additional datasets for near-shore ice conditions including in-situ observations can also be incorporated to better understand the effect of sea ice on seismic noise.

Presenting Author: Kasey Aderhold

Authors