Force Budget Analysis of Glacier Flow : Ice Dynamical Studies on Storglaciären, Sweden, and Ice Flow Investigations of Outlet Glaciers in Dronning Maud Land, Antarctica
This thesis contributes to the understanding of glacier response to climate change by ice dynamical studies on Storglaciären, Sweden, and Bonnevie-Svendsenbreen, Kibergbreen and Plogbreen in Dronning Maud Land, Antarctica. Ice surface velocities, ice geometry and temperature information is fed throu...
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Institutionen för geovetenskaper
2004
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ftuppsalauniv:oai:DiVA.org:uu-4219 2023-05-15T13:51:30+02:00 Force Budget Analysis of Glacier Flow : Ice Dynamical Studies on Storglaciären, Sweden, and Ice Flow Investigations of Outlet Glaciers in Dronning Maud Land, Antarctica Kraftbudgetanalys av glacialt flöde : Isdynamiska studier på Storglaciären, Sverige, och isflödesundersökningar av utlöparglaciärer i Drottning Maud Land, Antarktis Hedfors, Jim 2004 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4219 eng eng Institutionen för geovetenskaper Uppsala : Acta Universitatis Upsaliensis Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1104-232X 963 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4219 urn:isbn:91-554-5936-6 info:eu-repo/semantics/openAccess Physical geography and sedimentology force budget ice flux ice dynamics mass balance strain heating climate change Storglaciären Dronning Maud Land Antarctica Naturgeografi och sedimentologi Physical Geography Naturgeografi Doctoral thesis, comprehensive summary info:eu-repo/semantics/doctoralThesis text 2004 ftuppsalauniv 2023-02-23T21:58:35Z This thesis contributes to the understanding of glacier response to climate change by ice dynamical studies on Storglaciären, Sweden, and Bonnevie-Svendsenbreen, Kibergbreen and Plogbreen in Dronning Maud Land, Antarctica. Ice surface velocities, ice geometry and temperature information is fed through a force budget model to calculate ice mass outflux of these glacial systems via three-dimensional stress distributions for a flux-gate. Field data were collected through repeated DGPS and GPR observations on Storglaciären between July 2000 to September 2001 and on Kibergbreen and Plobreen during the SWEDARP 2002/03 expedition to Antarctica. The work was strongly supported by remotely-sensed information. The results from Storglaciären show a strength in the force budget model to discern both spatial and temporal variability in ice dynamical patterns. It highlights the influence of seasonality and bedrock topography upon glacier flow. A modeling experiment on Bonnevie-Svendsenbreen suggested that ice temperature increases substantially under conditions of high stress (≥0.4 MPa) due to strain-heating. This provides a positive feedback loop, increasing ice deformation, as long as it overcomes the advection of cool ice from the surface. These results explain, to some extent, the mechanism behind fast flowing ice streams. Mass flux caclulations from Bonnevie-Svendsenbreen suggest that the outflux given from force budget calculations can be used as a gauge for influx assuming steady state conditions. Plogbreen receives an influx of 0.48±0.1 km3 a-1 and expedites a discharge volume of 0.55±0.05 km3 a-1. This indicative negative mass balance is explained by a falling trend in upstream accumulation and the recent rise in global sea level, as it is likely to induce glacier acceleration due to a reduction in resistive forces at the site of the gate. This result is comparable with other Antarctic studies reporting negative mass balances, e.g. from WAIS, as caused by changes in the global atmospheric circulation pattern. Doctoral or Postdoctoral Thesis Antarc* Antarctic Antarctica Antarktis* Dronning Maud Land SWEDARP Uppsala University: Publications (DiVA) Antarctic Bonnevie-Svendsenbreen ENVELOPE(-11.450,-11.450,-74.813,-74.813) Dronning Maud Land Kibergbreen ENVELOPE(-11.800,-11.800,-74.867,-74.867) Plogbreen ENVELOPE(16.202,16.202,76.787,76.787) Storglaciären ENVELOPE(18.560,18.560,67.904,67.904) Svendsenbreen ENVELOPE(15.733,15.733,78.117,78.117) The Gate ENVELOPE(-124.937,-124.937,61.417,61.417) |
institution |
Open Polar |
collection |
Uppsala University: Publications (DiVA) |
op_collection_id |
ftuppsalauniv |
language |
English |
topic |
Physical geography and sedimentology force budget ice flux ice dynamics mass balance strain heating climate change Storglaciären Dronning Maud Land Antarctica Naturgeografi och sedimentologi Physical Geography Naturgeografi |
spellingShingle |
Physical geography and sedimentology force budget ice flux ice dynamics mass balance strain heating climate change Storglaciären Dronning Maud Land Antarctica Naturgeografi och sedimentologi Physical Geography Naturgeografi Hedfors, Jim Force Budget Analysis of Glacier Flow : Ice Dynamical Studies on Storglaciären, Sweden, and Ice Flow Investigations of Outlet Glaciers in Dronning Maud Land, Antarctica |
topic_facet |
Physical geography and sedimentology force budget ice flux ice dynamics mass balance strain heating climate change Storglaciären Dronning Maud Land Antarctica Naturgeografi och sedimentologi Physical Geography Naturgeografi |
description |
This thesis contributes to the understanding of glacier response to climate change by ice dynamical studies on Storglaciären, Sweden, and Bonnevie-Svendsenbreen, Kibergbreen and Plogbreen in Dronning Maud Land, Antarctica. Ice surface velocities, ice geometry and temperature information is fed through a force budget model to calculate ice mass outflux of these glacial systems via three-dimensional stress distributions for a flux-gate. Field data were collected through repeated DGPS and GPR observations on Storglaciären between July 2000 to September 2001 and on Kibergbreen and Plobreen during the SWEDARP 2002/03 expedition to Antarctica. The work was strongly supported by remotely-sensed information. The results from Storglaciären show a strength in the force budget model to discern both spatial and temporal variability in ice dynamical patterns. It highlights the influence of seasonality and bedrock topography upon glacier flow. A modeling experiment on Bonnevie-Svendsenbreen suggested that ice temperature increases substantially under conditions of high stress (≥0.4 MPa) due to strain-heating. This provides a positive feedback loop, increasing ice deformation, as long as it overcomes the advection of cool ice from the surface. These results explain, to some extent, the mechanism behind fast flowing ice streams. Mass flux caclulations from Bonnevie-Svendsenbreen suggest that the outflux given from force budget calculations can be used as a gauge for influx assuming steady state conditions. Plogbreen receives an influx of 0.48±0.1 km3 a-1 and expedites a discharge volume of 0.55±0.05 km3 a-1. This indicative negative mass balance is explained by a falling trend in upstream accumulation and the recent rise in global sea level, as it is likely to induce glacier acceleration due to a reduction in resistive forces at the site of the gate. This result is comparable with other Antarctic studies reporting negative mass balances, e.g. from WAIS, as caused by changes in the global atmospheric circulation pattern. |
format |
Doctoral or Postdoctoral Thesis |
author |
Hedfors, Jim |
author_facet |
Hedfors, Jim |
author_sort |
Hedfors, Jim |
title |
Force Budget Analysis of Glacier Flow : Ice Dynamical Studies on Storglaciären, Sweden, and Ice Flow Investigations of Outlet Glaciers in Dronning Maud Land, Antarctica |
title_short |
Force Budget Analysis of Glacier Flow : Ice Dynamical Studies on Storglaciären, Sweden, and Ice Flow Investigations of Outlet Glaciers in Dronning Maud Land, Antarctica |
title_full |
Force Budget Analysis of Glacier Flow : Ice Dynamical Studies on Storglaciären, Sweden, and Ice Flow Investigations of Outlet Glaciers in Dronning Maud Land, Antarctica |
title_fullStr |
Force Budget Analysis of Glacier Flow : Ice Dynamical Studies on Storglaciären, Sweden, and Ice Flow Investigations of Outlet Glaciers in Dronning Maud Land, Antarctica |
title_full_unstemmed |
Force Budget Analysis of Glacier Flow : Ice Dynamical Studies on Storglaciären, Sweden, and Ice Flow Investigations of Outlet Glaciers in Dronning Maud Land, Antarctica |
title_sort |
force budget analysis of glacier flow : ice dynamical studies on storglaciären, sweden, and ice flow investigations of outlet glaciers in dronning maud land, antarctica |
publisher |
Institutionen för geovetenskaper |
publishDate |
2004 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4219 |
long_lat |
ENVELOPE(-11.450,-11.450,-74.813,-74.813) ENVELOPE(-11.800,-11.800,-74.867,-74.867) ENVELOPE(16.202,16.202,76.787,76.787) ENVELOPE(18.560,18.560,67.904,67.904) ENVELOPE(15.733,15.733,78.117,78.117) ENVELOPE(-124.937,-124.937,61.417,61.417) |
geographic |
Antarctic Bonnevie-Svendsenbreen Dronning Maud Land Kibergbreen Plogbreen Storglaciären Svendsenbreen The Gate |
geographic_facet |
Antarctic Bonnevie-Svendsenbreen Dronning Maud Land Kibergbreen Plogbreen Storglaciären Svendsenbreen The Gate |
genre |
Antarc* Antarctic Antarctica Antarktis* Dronning Maud Land SWEDARP |
genre_facet |
Antarc* Antarctic Antarctica Antarktis* Dronning Maud Land SWEDARP |
op_relation |
Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1104-232X 963 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4219 urn:isbn:91-554-5936-6 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766255376144007168 |