A look beneath the ice shelves of western Dronning Maud Land, East Antarctica: subglacial topography linked to ice shelf stability
Antarctica’s ice shelves play a key role in stabilizing their related ice sheets. The ice shelves of western Dronning Maud Land – including the Ekström, Atka, Jelbart, Fimbul and Vigrid ice shelves – currently buttress a catchment that comprises an ice volume equivalent to 0.95 meters of sea level....
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ftawi:oai:epic.awi.de:51884 2023-07-16T03:54:19+02:00 A look beneath the ice shelves of western Dronning Maud Land, East Antarctica: subglacial topography linked to ice shelf stability Eisermann, Hannes Eagles, Graeme Ruppel, Antonia Smith, Emma Clare Jokat, Wilfried 2020-04-27 https://epic.awi.de/id/eprint/51884/ https://hdl.handle.net/10013/epic.475f9743-3b40-489f-8536-4081c3603041 unknown Eisermann, H. orcid:0000-0002-5604-6484 , Eagles, G. orcid:0000-0001-5325-0810 , Ruppel, A. , Smith, E. C. orcid:0000-0002-8672-8259 and Jokat, W. orcid:0000-0002-7793-5854 , Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany, Federal Institute for Geosciences and Natural Resources, Hannover, Germany, Faculty of Geosciences, University of Bremen, Bremen, Germany (2020) A look beneath the ice shelves of western Dronning Maud Land, East Antarctica: subglacial topography linked to ice shelf stability , EGU2020: Sharing Geoscience Online, April 2020 - May 2020 . doi:10.5194/egusphere-egu2020-3261 <https://doi.org/10.5194/egusphere-egu2020-3261> , hdl:10013/epic.475f9743-3b40-489f-8536-4081c3603041 EPIC3EGU2020: Sharing Geoscience Online, 2020-04-2020-05 Conference notRev 2020 ftawi https://doi.org/10.5194/egusphere-egu2020-3261 2023-06-25T23:19:51Z Antarctica’s ice shelves play a key role in stabilizing their related ice sheets. The ice shelves of western Dronning Maud Land – including the Ekström, Atka, Jelbart, Fimbul and Vigrid ice shelves – currently buttress a catchment that comprises an ice volume equivalent to 0.95 meters of sea level. Any future increase in ice shelf mass loss, with basal melting likely being the main cause, will inevitably accelerate ice sheet drainage and contribute to global sea level rise. Since basal melting largely depends on ice-ocean interactions, it is crucial to attain reliable and consistent bathymetry models to estimate water and heat exchange beneath these ice shelves. We have constructed bathymetry models for an area of about 63,000 km2 beneath the ice shelves of western Dronning Maud Land by inverting airborne gravity data, tied to radar, seismic, and offshore depth reference points. New high-resolution airborne magnetic data across the ice shelves point to Jurassic intrusions and seaward-dipping reflectors originating from Gondwana breakup; enabling us to consider geological density variations as part of the bathymetry modelling process. Our bathymetric models reveal deep glacial troughs beneath the ice shelves, and sills close to the continental shelf breaks which currently limit the possible entry of Warm Deep Water from the Southern Ocean. The present-day average thermocline depth is comparable to the average depths of saddles along the sills, which present gateways into the sub-ice cavities. This leads us to suggest a high sensitivity for these ice shelves to changes in ocean temperature and especially thermocline depth in the future. Once a significant amount of warm water overtops the sills, the deep troughs will allow for fast access to the grounding line, after which it seems there may be little to stop basal melting from rapidly eroding the ice shelves of western Dronning Maud Land. Conference Object Antarc* Antarctica Dronning Maud Land East Antarctica Ice Sheet Ice Shelf Ice Shelves Southern Ocean Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Atka ENVELOPE(151.789,151.789,60.835,60.835) Buttress ENVELOPE(-57.083,-57.083,-63.550,-63.550) Dronning Maud Land East Antarctica Southern Ocean |
institution |
Open Polar |
collection |
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
Antarctica’s ice shelves play a key role in stabilizing their related ice sheets. The ice shelves of western Dronning Maud Land – including the Ekström, Atka, Jelbart, Fimbul and Vigrid ice shelves – currently buttress a catchment that comprises an ice volume equivalent to 0.95 meters of sea level. Any future increase in ice shelf mass loss, with basal melting likely being the main cause, will inevitably accelerate ice sheet drainage and contribute to global sea level rise. Since basal melting largely depends on ice-ocean interactions, it is crucial to attain reliable and consistent bathymetry models to estimate water and heat exchange beneath these ice shelves. We have constructed bathymetry models for an area of about 63,000 km2 beneath the ice shelves of western Dronning Maud Land by inverting airborne gravity data, tied to radar, seismic, and offshore depth reference points. New high-resolution airborne magnetic data across the ice shelves point to Jurassic intrusions and seaward-dipping reflectors originating from Gondwana breakup; enabling us to consider geological density variations as part of the bathymetry modelling process. Our bathymetric models reveal deep glacial troughs beneath the ice shelves, and sills close to the continental shelf breaks which currently limit the possible entry of Warm Deep Water from the Southern Ocean. The present-day average thermocline depth is comparable to the average depths of saddles along the sills, which present gateways into the sub-ice cavities. This leads us to suggest a high sensitivity for these ice shelves to changes in ocean temperature and especially thermocline depth in the future. Once a significant amount of warm water overtops the sills, the deep troughs will allow for fast access to the grounding line, after which it seems there may be little to stop basal melting from rapidly eroding the ice shelves of western Dronning Maud Land. |
format |
Conference Object |
author |
Eisermann, Hannes Eagles, Graeme Ruppel, Antonia Smith, Emma Clare Jokat, Wilfried |
spellingShingle |
Eisermann, Hannes Eagles, Graeme Ruppel, Antonia Smith, Emma Clare Jokat, Wilfried A look beneath the ice shelves of western Dronning Maud Land, East Antarctica: subglacial topography linked to ice shelf stability |
author_facet |
Eisermann, Hannes Eagles, Graeme Ruppel, Antonia Smith, Emma Clare Jokat, Wilfried |
author_sort |
Eisermann, Hannes |
title |
A look beneath the ice shelves of western Dronning Maud Land, East Antarctica: subglacial topography linked to ice shelf stability |
title_short |
A look beneath the ice shelves of western Dronning Maud Land, East Antarctica: subglacial topography linked to ice shelf stability |
title_full |
A look beneath the ice shelves of western Dronning Maud Land, East Antarctica: subglacial topography linked to ice shelf stability |
title_fullStr |
A look beneath the ice shelves of western Dronning Maud Land, East Antarctica: subglacial topography linked to ice shelf stability |
title_full_unstemmed |
A look beneath the ice shelves of western Dronning Maud Land, East Antarctica: subglacial topography linked to ice shelf stability |
title_sort |
look beneath the ice shelves of western dronning maud land, east antarctica: subglacial topography linked to ice shelf stability |
publishDate |
2020 |
url |
https://epic.awi.de/id/eprint/51884/ https://hdl.handle.net/10013/epic.475f9743-3b40-489f-8536-4081c3603041 |
long_lat |
ENVELOPE(151.789,151.789,60.835,60.835) ENVELOPE(-57.083,-57.083,-63.550,-63.550) |
geographic |
Atka Buttress Dronning Maud Land East Antarctica Southern Ocean |
geographic_facet |
Atka Buttress Dronning Maud Land East Antarctica Southern Ocean |
genre |
Antarc* Antarctica Dronning Maud Land East Antarctica Ice Sheet Ice Shelf Ice Shelves Southern Ocean |
genre_facet |
Antarc* Antarctica Dronning Maud Land East Antarctica Ice Sheet Ice Shelf Ice Shelves Southern Ocean |
op_source |
EPIC3EGU2020: Sharing Geoscience Online, 2020-04-2020-05 |
op_relation |
Eisermann, H. orcid:0000-0002-5604-6484 , Eagles, G. orcid:0000-0001-5325-0810 , Ruppel, A. , Smith, E. C. orcid:0000-0002-8672-8259 and Jokat, W. orcid:0000-0002-7793-5854 , Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany, Federal Institute for Geosciences and Natural Resources, Hannover, Germany, Faculty of Geosciences, University of Bremen, Bremen, Germany (2020) A look beneath the ice shelves of western Dronning Maud Land, East Antarctica: subglacial topography linked to ice shelf stability , EGU2020: Sharing Geoscience Online, April 2020 - May 2020 . doi:10.5194/egusphere-egu2020-3261 <https://doi.org/10.5194/egusphere-egu2020-3261> , hdl:10013/epic.475f9743-3b40-489f-8536-4081c3603041 |
op_doi |
https://doi.org/10.5194/egusphere-egu2020-3261 |
_version_ |
1771551530553442304 |