Tidal bending and strand cracks at the Kamb Ice Stream groun

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TitleTidal bending and strand cracks at the Kamb Ice Stream grounding line, West AntarcticaAbstractAn extensive set of shore-parallel fractures are observed at the grounding line of Kamb Ice Stream (KIS) in West Antarctica. Seismicity measured in the grounding zone is, as elsewhere around Antarctica, tidally forced and moreover strand cracks propagate nearly exclusively on the falling tide. Measured surface deflection and a model of fracture propagation are used to conclude that bending on the falling tide favors propagation while bending on the rising tide suppresses propagation. Without the perturbation due to tidal bending, strand cracks would be rare and appear farther downstream than observed. We speculate that the very large number of cracks observed at KIS is due to the stagnant-to-floating transition at that grounding line, which allows cyclic bending of the same ice and relatively large stretching rates. Copyright The Author(s) 2016.AcknowledgementsWe thank Laurie Padman for the tide prediction and Harm Van Avendonk for the geophones of opportunity. We thank Doug MacAyeal for his council regarding the geophone data and two reviewers who asked important clarifying questions. The KIS and WIS strain grid data were used by Fiona Seifert in her MSc thesis, Origin of Surface Undulations at the Kamb Ice Stream Grounding Line, West Antarctica, at Portland State University. The field work was supported by NSF OPP grants ANT 05-38015 to Hulbe and ANT 05- 38120 to Catania. Support for data analysis was provided to Hulbe by the University of Otago. We appreciate the support of the University of Wisconsin Automatic Weather Station Program (NSF grants number ARC-0713843, ANT- 0944018, and/or ANT-1141908) where the atmospheric pressure data are archived.Funding DetailsANT-0944018, NSF, National Science Foundation; ANT-1141908, NSF, National Science Foundation; ARC-0713843, NSF, National Science Foundation

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1st AuthorHulbe, C.AuthorHulbe, C.Klinger, M.Masterson, M.Catania, G.Cruikshank, K.Bugni, A.Year2016JournalJournal of GlaciologyVolume62Number235Pages816-824DOI10.1017/jog.2016.74URLhttps://www.scopus.com/inward/recor.....b8e15383d574668b4e80fc1c6Keywordsrank1Author KeywordsGrounding lineIce fracture propagationIce shelves

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TypeArticleCitationHulbe, C., Klinger, M., Masterson, M., Catania, G., Cruikshank, K. and Bugni, A. (2016). Tidal bending and strand cracks at the Kamb Ice Stream grounding line, West Antarctica. Journal of Glaciology, 62(235): 816-824IdentifierHulbe2016aRelevancerank1