Show simple item record

dc.contributor.authorYoung, Tun
dc.date.accessioned2018-08-28T10:17:55Z
dc.date.available2018-08-28T10:17:55Z
dc.date.issued2018-09-30
dc.date.submitted2018-08-28
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/279019
dc.description.abstractThe dynamic response of a faster-flowing Greenland Ice Sheet to climate change is modulated by feedbacks between ice flow and surface meltwater delivery to the basal environment. While supraglacial melt processes have been thoroughly examined and are well constrained, the response of the englacial and subglacial environment to these seasonal perturbations still represent the least-studied, understood, and parameterised processes of glacier dynamics due to a paucity of direct observation. To better understand these processes in the wake of a changing climate, novel in-situ geophysical experiments were undertaken on Store Glacier in west Greenland to quantify rates of englacial deformation and basal melting. The records produced from these experiments yield new insights into the thermodynamic setting of a major outlet glacier, and the physical mechanisms underlying and resulting from fast glacier motion. The deployment of autonomous phase-sensitive radio-echo sounders (ApRES) 30 km from the calving terminus of Store Glacier between 2014 and 2016 revealed high rates of both englacial deformation and basal melting, driven primarily by the dynamic response of the basal hydrological system to seasonal surface meltwater influxes. Thermodynamic modelling of this process revealed a convergence of large-scale basal hydrological pathways that aggregated large amounts of water towards the field site. The warm, turbulent water routed from surface melt contained and dissipated enough energy at the ice-bed interface to explain the observed high melt rates. Simultaneously, changes in the local strain field, involving seasonal variations in the morphology of internal layers, were found to be the result of far-field perturbations in downstream ice flow which propagated tens of kilometres upglacier through longitudinal stress coupling. When observed in multiple dimensions, the layer structure revealed complex internal reflection geometries, demonstrating ApRES as not just a monitor of depth changes in ice thickness, but also as an imaging instrument capable of characterising the subsurface environment within and beneath ice sheets. Altogether, the observations and analyses comprising this thesis provide new and significant insight and understanding into the structural, thermal, and mechanical processes tied to Store Glacier and its fast, complex, and dynamic ice flow.
dc.description.sponsorshipThis thesis was completed in conjunction with the NERC-funded Subglacial Access and Fast Ice Research Experiment (SAFIRE; NE/K005871/1) and a scholarship from Chung Wei Yi Co. Ltd.
dc.language.isoen
dc.rightsAttribution-NonCommercial 4.0 International (CC BY-NC 4.0)
dc.rights.urihttps://creativecommons.org/licenses/by-nc/4.0/
dc.subjectGreenland
dc.subjectGlaciology
dc.subjectRadioglaciology
dc.subjectRadar
dc.titleInvestigating fast flow of the Greenland Ice Sheet
dc.typeThesis
dc.type.qualificationlevelDoctoral
dc.type.qualificationnameDoctor of Philosophy (PhD)
dc.publisher.institutionUniversity of Cambridge
dc.publisher.departmentScott Polar Research Institute
dc.date.updated2018-08-23T12:29:34Z
dc.identifier.doi10.17863/CAM.26392
rioxxterms.licenseref.urihttps://creativecommons.org/licenses/by-nc/4.0/
dc.contributor.orcidYoung, Tun [0000-0001-5865-3459]
dc.publisher.collegeSt. Edmund's College
dc.type.qualificationtitlePhD in Polar Studies
cam.supervisorChristoffersen, Poul
cam.supervisor.orcidChristoffersen, Poul [0000-0003-2643-8724]
cam.supervisor.orcidNicholls, Keith W [0000-0002-2188-4509]
cam.thesis.fundingfalse
rioxxterms.freetoread.startdate2019-08-28


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record

Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
Except where otherwise noted, this item's licence is described as Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)