Seasonal and spatial variations in the ocean-coupled ambient wavefield of the Ross Ice Shelf

Abstract The Ross Ice Shelf (RIS) is host to a broadband, multimode seismic wavefield that is excited in response to atmospheric, oceanic and solid Earth source processes. A 34-station broadband seismographic network installed on the RIS from late 2014 through early 2017 produced continuous vibratio...

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Bibliographic Details
Published inJournal of glaciology Vol. 65; no. 254; pp. 912 - 925
Main Authors Baker, Michael G., Aster, Richard C., Anthony, Robert E., Chaput, Julien, Wiens, Douglas A., Nyblade, Andrew, Bromirski, Peter D., Gerstoft, Peter, Stephen, Ralph A.
Format Journal Article
LanguageEnglish
Published Cambridge Cambridge University Press 01.12.2019
Subjects
Antarctic glaciology
Background levels
Baseline studies
Broadband
Earth
Earthquakes
Floating
Gravitational waves
Gravity
Ice
Ice front
Ice fronts
Ice shelves
Land ice
Noise
Ocean waves
Oceans
S waves
Sea ice
Seismography
Seismology
Signal processing
Spatial variations
Stations
Ross Sea
Antarctica
Roosevelt Island
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Summary:Abstract The Ross Ice Shelf (RIS) is host to a broadband, multimode seismic wavefield that is excited in response to atmospheric, oceanic and solid Earth source processes. A 34-station broadband seismographic network installed on the RIS from late 2014 through early 2017 produced continuous vibrational observations of Earth's largest ice shelf at both floating and grounded locations. We characterize temporal and spatial variations in broadband ambient wavefield power, with a focus on period bands associated with primary (10–20 s) and secondary (5–10 s) microseism signals, and an oceanic source process near the ice front (0.4–4.0 s). Horizontal component signals on floating stations overwhelmingly reflect oceanic excitations year-round due to near-complete isolation from solid Earth shear waves. The spectrum at all periods is shown to be strongly modulated by the concentration of sea ice near the ice shelf front. Contiguous and extensive sea ice damps ocean wave coupling sufficiently so that wintertime background levels can approach or surpass those of land-sited stations in Antarctica.
ISSN:0022-1430
1727-5652
DOI:10.1017/jog.2019.64