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Transoceanic infragravity waves impacting Antarctic ice shelves
Author(s) -
Bromirski Peter D.,
Sergienko Olga V.,
MacAyeal Douglas R.
Publication year - 2010
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2009gl041488
Subject(s) - geology , swell , infragravity wave , ice shelf , sea ice , forcing (mathematics) , oceanography , fast ice , lead (geology) , antarctic sea ice , drift ice , wind wave , seismology , continental shelf , arctic ice pack , geophysics , climatology , wave propagation , longitudinal wave , geomorphology , cryosphere , mechanical wave , physics , quantum mechanics
Long‐period oceanic infragravity (IG) waves ( ca. [250, 50] s period) are generated along continental coastlines by nonlinear wave interactions of storm‐forced shoreward propagating swell. Seismic observations on the Ross Ice Shelf show that free IG waves generated along the Pacific coast of North America propagate transoceanically to Antarctica, where they induce a much higher amplitude shelf response than ocean swell ( ca. [30, 12] s period). Additionally, unlike ocean swell, IG waves are not significantly damped by sea ice, and thus impact the ice shelf throughout the year. The response of the Ross Ice Shelf to IG‐wave induced flexural stresses is more than 60 dB greater than concurrent ground motions measured at nearby Scott Base. This strong coupling suggests that IG‐wave forcing may produce ice‐shelf fractures that enable abrupt disintegration of ice shelves that are also affected by strong surface melting. Bolstering this hypothesis, each of the 2008 breakup events of the Wilkins Ice Shelf coincides with wave‐model‐estimated arrival of IG‐wave energy from the Patagonian coast.