Ross ice shelf icequakes associated with ocean gravity wave activity

• Published in: Geophysical Research Letters
• Main Authors: Chen, Zhao, Bromirski, Peter D., Gerstoft, Peter, Stephen, Ralph A., Lee, Won Sang, Yun, Sukyoung, Olinger, Seth D., Aster, Richard C., Wiens, Douglas A., Nyblade, Andrew A.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Geophysical Union 2019
• Subjects: Icequake; Ice shelf; Gravity wave; Transfer function; Austral; Ross Ice Shelf; Ice Shelf; Ice Shelves; Sea ice
• Online Access: https://hdl.handle.net/1912/24863

Author Posting. © American Geophysical Union, 2019. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 46(15), (2019): 8893-8902, doi:10.1029/2019GL084123. Gravity waves impacting ice shelves illicit a suite of responses that can affect ice shelf integrity. Broadband seismometers deployed on the Ross Ice Shelf, complemented by a near‐icefront seafloor hydrophone, establish the association of strong icequake activity with ocean gravity wave amplitudes (AG) below 0.04 Hz. The Ross Ice Shelf‐front seismic vertical displacement amplitudes (ASV) are well correlated with AG, allowing estimating the frequency‐dependent transfer function from gravity wave amplitude to icefront vertical displacement amplitude (TGSV(f)). TGSV(f) is 0.6–0.7 at 0.001–0.01 Hz but decreases rapidly at higher frequencies. Seismicity of strong icequakes exhibits spatial and seasonal associations with different gravity wave frequency bands, with the strongest icequakes observed at the icefront primarily during the austral summer when sea ice is minimal and swell impacts are strongest. Bromirski, Gerstoft, and Chen were supported by NSF grant PLR‐1246151. Bromirski also received support from NSF grant OPP‐1744856 and CAL‐DPR‐C1670002. Stephen, Wiens, Aster, and Nyblade were supported under NSF grants PLR‐1246416, 1142518, 1141916, and 1142126, respectively. Lee and Yun were support by a research grant from the Korean Ministry of Oceans and Fisheries (KIMST20190361; PM19020). Seismic instruments and on‐ice support were provided by the Incorporated Research Institutions for Seismology (IRIS) through the PASSCAL Instrument Center at New Mexico Tech. The RIS and KPDR seismic data are archived at the IRIS Data Management Center, http://ds.iris.edu/ds/nodes/dmc/, with network codes XH and KP, respectively. The facilities of the IRIS Consortium are supported by the National Science Foundation under Cooperative Agreement ...