High basal melting forming a channel at the grounding line o
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TitleHigh basal melting forming a channel at the grounding line of Ross Ice Shelf, AntarcticaAbstractAntarctica's ice shelves are thinning at an increasing rate, affecting their buttressing ability. Channels in the ice shelf base unevenly distribute melting, and their evolution provides insight into changing subglacial and oceanic conditions. Here we used phase-sensitive radar measurements to estimate basal melt rates in a channel beneath the currently stable Ross Ice Shelf. Melt rates of 22.2 ± 0.2 m a-1 (greater than 2500% the overall background rate) were observed 1.7 km seaward of Mercer/Whillans Ice Stream grounding line, close to where subglacial water discharge is expected. Laser altimetry shows a corresponding, steadily deepening surface channel. Two relict channels to the north suggest recent subglacial drainage reorganization beneath Whillans Ice Stream approximately coincident with the shutdown of Kamb Ice Stream. This rapid channel formation implies that shifts in subglacial hydrology may impact ice shelf stability. Copyright 2015. American Geophysical Union. All Rights Reserved.AcknowledgementsThe authors would like to thank NSF and the WISSARD project (PLR 1439774and 0838854), NY Air National Guard,UNAVCO, and ASC for logistical support. Esteban Chaves and Sarah Neuhaus provided assistance with data collectionin the field. TerraSAR -X data were provided through the HYD2869 project. We thank NASA's ICESat Science Project and the NSIDC for distribution of ICESatdata. H.F. would like to thank the John Dove Isaacs Chair funds which supported much of this work. H.F. and M.S. were supported by NASA grantNNX13AP60G. The manuscript waswritten by O.M. with contributions from all authors. H.F., K.C., O.M., and M.S.conceived the study. O.M., M.S., and G.C.collected, processed, and analyzed phase-sensitive radar, GPS, and ice-penetrating radar data, respectively. O.M. and H.F. processed satellite data. H.C.and K.N. provided radar equipment and assisted O.M. with phase-sensitive radar processing and analysis. Data are available by contacting the authors directly.
1st AuthorMarsh, O.AuthorMarsh, O.Fricker, H.Siegfried, M.Christianson, K.Nicholls, K.Corr, H.Catania, G.Year2016JournalGeophysical Research LettersVolume43Number1Pages1/06/2017DOI10.1002/2015GL066612URLhttps://www.scopus.com/inward/recor.....893defa68ade242af93215326KeywordsGlacial geologyMeltingRadarRadar measurement, Channel formationIce shelvesIce streamsOceanic conditionsPhase sensitiveRoss ice shelvesSubglacial hydrologySubglacial waters, Ice, basal meltingchannelizationdischargedrainageglacial hydrologygrounding lineice shelflaser methodradarsubglacial environment, Antarctic Ice SheetAntarcticaKamb Ice StreamMercer Ice StreamRoss Ice ShelfWest Antarctic Ice SheetWest AntarcticaWhillans Ice Stream, rank3Author Keywordsice shelf channelsphase-sensitive radarWhillans Ice StreamProgrammeK001 - Past Antarctic Climate Programme (PAC)
TypeArticleCitationMarsh, O., Fricker, H., Siegfried, M., Christianson, K., Nicholls, K., Corr, H. and Catania, G. (2016). High basal melting forming a channel at the grounding line of Ross Ice Shelf, Antarctica. Geophysical Research Letters, 43(1): 1-6
Catania, G., High basal melting forming a channel at the grounding line o , [Marsh2016]. Antarctica NZ, accessed 30/01/2023, https://adam.antarcticanz.govt.nz/nodes/view/63644, 10.1002/2015GL066612