In-situ temperature measurements for deriving geothermal heat flux in the Amundsen Sea Embayment
Elevated and/or spatially variable geothermal heat flux (GHF) is suspected to affect basal conditions of ice sheets, i.e. basal melting and subglacial hydrology. Thermomechanical models demonstrate the influential boundary condition of geothermal heat flux for (paleo) ice sheet stability. Due to a c...
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ftawi:oai:epic.awi.de:45884 2023-05-15T13:23:52+02:00 In-situ temperature measurements for deriving geothermal heat flux in the Amundsen Sea Embayment Dziadek, Ricarda Gohl, Karsten Kaul, Norbert 2017-09-20 https://epic.awi.de/id/eprint/45884/ https://hdl.handle.net/10013/epic.51976 unknown Dziadek, R. , Gohl, K. orcid:0000-0002-9558-2116 and Kaul, N. (2017) In-situ temperature measurements for deriving geothermal heat flux in the Amundsen Sea Embayment , DFG Koordinationsworkshop SPP 1158, Erlangen, 20 September 2017 - 22 September 2017 . hdl:10013/epic.51976 EPIC3DFG Koordinationsworkshop SPP 1158, Erlangen, 2017-09-20-2017-09-22 Conference notRev 2017 ftawi 2021-12-24T15:43:25Z Elevated and/or spatially variable geothermal heat flux (GHF) is suspected to affect basal conditions of ice sheets, i.e. basal melting and subglacial hydrology. Thermomechanical models demonstrate the influential boundary condition of geothermal heat flux for (paleo) ice sheet stability. Due to a complex tectonic and magmatic history of West Antarctica, the region is suspected to exhibit strong heterogeneous geothermal heat flux variations [e.g. Schroeder et al., 2014; Fisher et al., 2015]. Although the maximum ice extent has retreated from the shelf since the last glacial maximum, the trends of offshore GHF patterns and the overall order of magnitude are hypothetically related to those areas onshore where the West Antarctic Ice Sheet (WAIS) rests on geologically related structures. High-resolution GHF will aid the understanding of the paleo-retreat of the ice sheet in this sector. The problem with testing these possibilities is that direct observations of GHF in Antarctica are so sparse that it is accounted for the greatest source of uncertainty in ice sheet studies for the continent [Larour et al., 2012]. This presentation builds on our previous studies in which we discussed geothermal heat flux based on 26 in-situ temperature measurements that were conducted in 2010 in the Amundsen Sea Embayment (ASE) in West Antarctica. We found, that the shallow (3 m) in-situ temperature measurements were likely influenced by inter-annual bottom-water temperature variability, leading to GHF estimates biased towards lower values (mean = 33 mWm-²). In contrast, our numerical models of geothermal heat fluxes, based on Depth-to-the-Bottom-of-the-Magnetic-Source estimates, suggest that GHF spatially varies from 68 to 110 mWm-². During RV Polarstern expedition PS104 in early 2017 we collected additional 28 in-situ temperature measurements in marine sediments (up to 11 m probe depth) for deriving geothermal heat flux in the ASE, which will overall improve the spatial coverage of this region. We present GHF results of this novel data set and discuss challenges of measuring in-situ temperatures for GHF in the Amundsen Sea Embayment. Conference Object Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet West Antarctica Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Amundsen Sea Antarctic West Antarctic Ice Sheet West Antarctica |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
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ftawi |
language |
unknown |
description |
Elevated and/or spatially variable geothermal heat flux (GHF) is suspected to affect basal conditions of ice sheets, i.e. basal melting and subglacial hydrology. Thermomechanical models demonstrate the influential boundary condition of geothermal heat flux for (paleo) ice sheet stability. Due to a complex tectonic and magmatic history of West Antarctica, the region is suspected to exhibit strong heterogeneous geothermal heat flux variations [e.g. Schroeder et al., 2014; Fisher et al., 2015]. Although the maximum ice extent has retreated from the shelf since the last glacial maximum, the trends of offshore GHF patterns and the overall order of magnitude are hypothetically related to those areas onshore where the West Antarctic Ice Sheet (WAIS) rests on geologically related structures. High-resolution GHF will aid the understanding of the paleo-retreat of the ice sheet in this sector. The problem with testing these possibilities is that direct observations of GHF in Antarctica are so sparse that it is accounted for the greatest source of uncertainty in ice sheet studies for the continent [Larour et al., 2012]. This presentation builds on our previous studies in which we discussed geothermal heat flux based on 26 in-situ temperature measurements that were conducted in 2010 in the Amundsen Sea Embayment (ASE) in West Antarctica. We found, that the shallow (3 m) in-situ temperature measurements were likely influenced by inter-annual bottom-water temperature variability, leading to GHF estimates biased towards lower values (mean = 33 mWm-²). In contrast, our numerical models of geothermal heat fluxes, based on Depth-to-the-Bottom-of-the-Magnetic-Source estimates, suggest that GHF spatially varies from 68 to 110 mWm-². During RV Polarstern expedition PS104 in early 2017 we collected additional 28 in-situ temperature measurements in marine sediments (up to 11 m probe depth) for deriving geothermal heat flux in the ASE, which will overall improve the spatial coverage of this region. We present GHF results of this novel data set and discuss challenges of measuring in-situ temperatures for GHF in the Amundsen Sea Embayment. |
format |
Conference Object |
author |
Dziadek, Ricarda Gohl, Karsten Kaul, Norbert |
spellingShingle |
Dziadek, Ricarda Gohl, Karsten Kaul, Norbert In-situ temperature measurements for deriving geothermal heat flux in the Amundsen Sea Embayment |
author_facet |
Dziadek, Ricarda Gohl, Karsten Kaul, Norbert |
author_sort |
Dziadek, Ricarda |
title |
In-situ temperature measurements for deriving geothermal heat flux in the Amundsen Sea Embayment |
title_short |
In-situ temperature measurements for deriving geothermal heat flux in the Amundsen Sea Embayment |
title_full |
In-situ temperature measurements for deriving geothermal heat flux in the Amundsen Sea Embayment |
title_fullStr |
In-situ temperature measurements for deriving geothermal heat flux in the Amundsen Sea Embayment |
title_full_unstemmed |
In-situ temperature measurements for deriving geothermal heat flux in the Amundsen Sea Embayment |
title_sort |
in-situ temperature measurements for deriving geothermal heat flux in the amundsen sea embayment |
publishDate |
2017 |
url |
https://epic.awi.de/id/eprint/45884/ https://hdl.handle.net/10013/epic.51976 |
geographic |
Amundsen Sea Antarctic West Antarctic Ice Sheet West Antarctica |
geographic_facet |
Amundsen Sea Antarctic West Antarctic Ice Sheet West Antarctica |
genre |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet West Antarctica |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet West Antarctica |
op_source |
EPIC3DFG Koordinationsworkshop SPP 1158, Erlangen, 2017-09-20-2017-09-22 |
op_relation |
Dziadek, R. , Gohl, K. orcid:0000-0002-9558-2116 and Kaul, N. (2017) In-situ temperature measurements for deriving geothermal heat flux in the Amundsen Sea Embayment , DFG Koordinationsworkshop SPP 1158, Erlangen, 20 September 2017 - 22 September 2017 . hdl:10013/epic.51976 |
_version_ |
1766375975194460160 |