Hydrology and Bed Topography of the Greenland Ice Sheet : Last known surroundings
The increased temperatures in the Arctic accelerate the loss of land based ice stored in glaciers. The Greenland Ice Sheet is the largest ice mass in the Northern Hemisphere and holds ~10% of all the freshwater on Earth, equivalent to ~7 metres of global sea level rise. A few decades ago, the mass b...
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Uppsala universitet, Luft-, vatten- och landskapslära
2015
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ftuppsalauniv:oai:DiVA.org:uu-259076 2023-05-15T15:19:11+02:00 Hydrology and Bed Topography of the Greenland Ice Sheet : Last known surroundings Lindbäck, Katrin 2015 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-259076 eng eng Uppsala universitet, Luft-, vatten- och landskapslära Uppsala Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1651-6214 1265 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-259076 urn:isbn:978-91-554-9280-9 info:eu-repo/semantics/openAccess climate change Greenland Ice Sheet radio-echo sounding digital elevation models ice thickness bed topography spectral analysis roughness subglacial hydrology water piracy englacial features drainage catchments meltwater runoff ice dynamics klimatförändringar Grönlands inlandsis markbaserad radar digitala höjdmodeller istjocklek bottentopografi spektralanalys subglacial hydrologi englaciala strukturer avrinningsområden isdynamik Physical Geography Naturgeografi Doctoral thesis, comprehensive summary info:eu-repo/semantics/doctoralThesis text 2015 ftuppsalauniv 2023-02-23T21:52:08Z The increased temperatures in the Arctic accelerate the loss of land based ice stored in glaciers. The Greenland Ice Sheet is the largest ice mass in the Northern Hemisphere and holds ~10% of all the freshwater on Earth, equivalent to ~7 metres of global sea level rise. A few decades ago, the mass balance of the Greenland Ice Sheet was poorly known and assumed to have little impact on global sea level rise. The development of regional climate models and remote sensing of the ice sheet during the past decade have revealed a significant mass loss. To monitor how the Greenland Ice Sheet will affect sea levels in the future requires understanding the physical processes that govern its mass balance and movement. In the southeastern and central western regions, mass loss is dominated by the dynamic behaviour of ice streams calving into the ocean. Changes in surface mass balance dominate mass loss from the Greenland Ice Sheet in the central northern, southwestern and northeastern regions. Little is known about what the hydrological system looks like beneath the ice sheet; how well the hydrological system is developed decides the water’s impact on ice movement. In this thesis, I have focused on radar sounding measurements to map the subglacial topography in detail for a land-terminating section of the western Greenland Ice Sheet. This knowledge is a critical prerequisite for any subglacial hydrological modelling. Using the high-resolution ice thickness and bed topography data, I have made the following specific studies: First, I have analysed the geological setting and glaciological history of the region by comparing proglacial and subglacial spectral roughness. Second, I have analysed the subglacial water drainage routing and revealed a potential for subglacial water piracy between adjacent subglacial water catchments with changes in the subglacial water pressure regime. Finally, I have looked in more detail into englacial features that are commonly observed in radar sounding data from western Greenland. In all, the ... Doctoral or Postdoctoral Thesis Arctic Climate change Greenland Ice Sheet Inlandsis Uppsala University: Publications (DiVA) Arctic Greenland |
institution |
Open Polar |
collection |
Uppsala University: Publications (DiVA) |
op_collection_id |
ftuppsalauniv |
language |
English |
topic |
climate change Greenland Ice Sheet radio-echo sounding digital elevation models ice thickness bed topography spectral analysis roughness subglacial hydrology water piracy englacial features drainage catchments meltwater runoff ice dynamics klimatförändringar Grönlands inlandsis markbaserad radar digitala höjdmodeller istjocklek bottentopografi spektralanalys subglacial hydrologi englaciala strukturer avrinningsområden isdynamik Physical Geography Naturgeografi |
spellingShingle |
climate change Greenland Ice Sheet radio-echo sounding digital elevation models ice thickness bed topography spectral analysis roughness subglacial hydrology water piracy englacial features drainage catchments meltwater runoff ice dynamics klimatförändringar Grönlands inlandsis markbaserad radar digitala höjdmodeller istjocklek bottentopografi spektralanalys subglacial hydrologi englaciala strukturer avrinningsområden isdynamik Physical Geography Naturgeografi Lindbäck, Katrin Hydrology and Bed Topography of the Greenland Ice Sheet : Last known surroundings |
topic_facet |
climate change Greenland Ice Sheet radio-echo sounding digital elevation models ice thickness bed topography spectral analysis roughness subglacial hydrology water piracy englacial features drainage catchments meltwater runoff ice dynamics klimatförändringar Grönlands inlandsis markbaserad radar digitala höjdmodeller istjocklek bottentopografi spektralanalys subglacial hydrologi englaciala strukturer avrinningsområden isdynamik Physical Geography Naturgeografi |
description |
The increased temperatures in the Arctic accelerate the loss of land based ice stored in glaciers. The Greenland Ice Sheet is the largest ice mass in the Northern Hemisphere and holds ~10% of all the freshwater on Earth, equivalent to ~7 metres of global sea level rise. A few decades ago, the mass balance of the Greenland Ice Sheet was poorly known and assumed to have little impact on global sea level rise. The development of regional climate models and remote sensing of the ice sheet during the past decade have revealed a significant mass loss. To monitor how the Greenland Ice Sheet will affect sea levels in the future requires understanding the physical processes that govern its mass balance and movement. In the southeastern and central western regions, mass loss is dominated by the dynamic behaviour of ice streams calving into the ocean. Changes in surface mass balance dominate mass loss from the Greenland Ice Sheet in the central northern, southwestern and northeastern regions. Little is known about what the hydrological system looks like beneath the ice sheet; how well the hydrological system is developed decides the water’s impact on ice movement. In this thesis, I have focused on radar sounding measurements to map the subglacial topography in detail for a land-terminating section of the western Greenland Ice Sheet. This knowledge is a critical prerequisite for any subglacial hydrological modelling. Using the high-resolution ice thickness and bed topography data, I have made the following specific studies: First, I have analysed the geological setting and glaciological history of the region by comparing proglacial and subglacial spectral roughness. Second, I have analysed the subglacial water drainage routing and revealed a potential for subglacial water piracy between adjacent subglacial water catchments with changes in the subglacial water pressure regime. Finally, I have looked in more detail into englacial features that are commonly observed in radar sounding data from western Greenland. In all, the ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Lindbäck, Katrin |
author_facet |
Lindbäck, Katrin |
author_sort |
Lindbäck, Katrin |
title |
Hydrology and Bed Topography of the Greenland Ice Sheet : Last known surroundings |
title_short |
Hydrology and Bed Topography of the Greenland Ice Sheet : Last known surroundings |
title_full |
Hydrology and Bed Topography of the Greenland Ice Sheet : Last known surroundings |
title_fullStr |
Hydrology and Bed Topography of the Greenland Ice Sheet : Last known surroundings |
title_full_unstemmed |
Hydrology and Bed Topography of the Greenland Ice Sheet : Last known surroundings |
title_sort |
hydrology and bed topography of the greenland ice sheet : last known surroundings |
publisher |
Uppsala universitet, Luft-, vatten- och landskapslära |
publishDate |
2015 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-259076 |
geographic |
Arctic Greenland |
geographic_facet |
Arctic Greenland |
genre |
Arctic Climate change Greenland Ice Sheet Inlandsis |
genre_facet |
Arctic Climate change Greenland Ice Sheet Inlandsis |
op_relation |
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1651-6214 1265 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-259076 urn:isbn:978-91-554-9280-9 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766349364019593216 |