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dc.contributor.authorGimbert, Florent
dc.contributor.authorTsai, Victor C.
dc.contributor.authorAmundson, Jason M.
dc.contributor.authorBartholomaus, Timothy, C.
dc.contributor.authorWalter, Jacob I.
dc.date.accessioned2020-07-22T19:13:42Z
dc.date.available2020-07-22T19:13:42Z
dc.date.issued2016-04-07
dc.identifier.citationGimbert, F., V. C. Tsai, J. M. Amundson, T. C. Bartholomaus, and J. I. Walter (2016), Subseasonal changes observed in subglacial channel pressure, size, and sediment transport, Geophys. Res. Lett., 43, doi:10.1002/2016GL068337.en_US
dc.identifier.urihttp://hdl.handle.net/11122/11192
dc.descriptionWater that pressurizes the base of glaciers and ice sheets enhances glacier velocities and modulates glacial erosion. Predicting ice flow and erosion therefore requires knowledge of subglacial channel evolution, which remains observationally limited.en_US
dc.description.abstractWater that pressurizes the base of glaciers and ice sheets enhances glacier velocities and modulates glacial erosion. Predicting ice flow and erosion therefore requires knowledge of subglacial channel evolution, which remains observationally limited. Here we demonstrate that detailed analysis of seismic ground motion caused by subglacial water flow at Mendenhall Glacier (Alaska) allows for continuous measurement of daily to subseasonal changes in basal water pressure gradient, channel size, and sediment transport. We observe intermittent subglacial water pressure gradient changes during the melt season, at odds with common assumptions of slowly varying, low-pressure channels. These observations indicate that changes in channel size do not keep pace with changes in discharge. This behavior strongly affects glacier dynamics and subglacial channel erosion at Mendenhall Glacier, where episodic periods of high water pressure gradients enhance glacier surface velocity and channel sediment transport by up to 30% and 50%, respectively. We expect the application of this framework to future seismic observations acquired at glaciers worldwide to improve our understanding of subglacial processes.en_US
dc.description.sponsorshipThis study was funded by NSF grant EAR-1453263. We thank Flavien Beaud and an anonymous reviewer for thorough reviews that improved the manuscript. We also thank Michael Lamb, Olivier Gagliardini, Jean-Philippe Avouac, Gael Durand and Adrien Gilbert for fruitful discussions.en_US
dc.language.isoen_USen_US
dc.publisherAmerican Geophysical Unionen_US
dc.subjectsubglacial channel evolutionen_US
dc.subjectglacial erosionen_US
dc.subjectMendenhall Glacieren_US
dc.subjectsubglacial water pressueen_US
dc.subjectglacier dynamicsen_US
dc.subjectsubglacial processessen_US
dc.titleSubseasonal changes observed in subglacial channel pressure, size, and sediment transporten_US
dc.title.alternativeResearch Letteren_US
dc.typeArticleen_US
dc.description.peerreviewYesen_US
refterms.dateFOA2020-07-22T19:13:42Z
dc.identifier.journalGeophysical Research Lettersen_US


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