Computational Modelling of Coupled Heat Transport between the Heterogeneous Earth and an Overlying Ice Sheet
Due to a complex interplay between the Earth and overlying ice sheets, a large variety of subglacial landforms developed. One example is the in the North German Basin widely spread phenomenon of tunnel valleys. An observed correlation to underlying salt structures is often explained mechanically. We...
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ftsubggeo:oai:e-docs.geo-leo.de:11858/8303 2023-05-15T16:40:45+02:00 Computational Modelling of Coupled Heat Transport between the Heterogeneous Earth and an Overlying Ice Sheet Bodenburg, Sascha Reiche, Sönke Blachut, Wojciech Hübscher, Christian Kowalski, Julia 2021 https://doi.org/10.23689/fidgeo-3963 http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/8303 eng eng 81. Jahrestagung der Deutschen Geophysikalischen Gesellschaft (DGG), 01.-05.03.2021, Kiel doi:10.23689/fidgeo-3963 http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/8303 CC::CC BY 4.0 CC-BY ddc:550 doc-type:conferenceObject 2021 ftsubggeo https://doi.org/10.23689/fidgeo-3963 2022-12-04T23:12:17Z Due to a complex interplay between the Earth and overlying ice sheets, a large variety of subglacial landforms developed. One example is the in the North German Basin widely spread phenomenon of tunnel valleys. An observed correlation to underlying salt structures is often explained mechanically. We focus on an alternative hypothesis based on thermodynamic processes: As salt better conducts heat than the surrounding rocks, the geothermal heat flux is augmented above salt structures. This leads to melting processes at the interface between the Earth and the ice sheet. The subglacial rivers finally erode the tunnel valleys. To test this hypothesis, we model related hydrothermal processes by means of a finite-difference open-source code (SHEMAT-Suit). The model accounts for heat conduction, groundwater flows, processes in the glaciothermal system such as the motion and spatiotemporal temperature evolution within the ice, and finally the coupling of both at the subglacial interface to account for the feedback mechanisms. Glaciothermal system and coupling processes are incorporated based on an idealized 1D model for the ice cover. We present a scaling analysis to discuss dominant processes. Our results show that a purely conductive subsurface (complete absence of groundwater flow) leads to a very moderate increase of the geothermal heat flux above salt structures. This implies a slight increase of the melting rates, which by itself is not enough to trigger tunnel valley erosion. Additional hydrothermal flows e.g. through fault zones may increase the subglacial melting rates. In this contribution, we will present results from a case study in the Southern North Sea. A 2D seismic section includes two tunnel valleys above salt structures. To model the state prior to erosion and sedimentation during and after the Quaternary glaciations, the Quaternary strata is replaced by strata with the same physical properties and thicknesses than the Paleocene to Miocene strata. Simulation runs with SHEMAT-Suite calculated the ... Conference Object Ice Sheet GEO-LEOe-docs (FID GEO) |
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English |
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ddc:550 Bodenburg, Sascha Reiche, Sönke Blachut, Wojciech Hübscher, Christian Kowalski, Julia Computational Modelling of Coupled Heat Transport between the Heterogeneous Earth and an Overlying Ice Sheet |
topic_facet |
ddc:550 |
description |
Due to a complex interplay between the Earth and overlying ice sheets, a large variety of subglacial landforms developed. One example is the in the North German Basin widely spread phenomenon of tunnel valleys. An observed correlation to underlying salt structures is often explained mechanically. We focus on an alternative hypothesis based on thermodynamic processes: As salt better conducts heat than the surrounding rocks, the geothermal heat flux is augmented above salt structures. This leads to melting processes at the interface between the Earth and the ice sheet. The subglacial rivers finally erode the tunnel valleys. To test this hypothesis, we model related hydrothermal processes by means of a finite-difference open-source code (SHEMAT-Suit). The model accounts for heat conduction, groundwater flows, processes in the glaciothermal system such as the motion and spatiotemporal temperature evolution within the ice, and finally the coupling of both at the subglacial interface to account for the feedback mechanisms. Glaciothermal system and coupling processes are incorporated based on an idealized 1D model for the ice cover. We present a scaling analysis to discuss dominant processes. Our results show that a purely conductive subsurface (complete absence of groundwater flow) leads to a very moderate increase of the geothermal heat flux above salt structures. This implies a slight increase of the melting rates, which by itself is not enough to trigger tunnel valley erosion. Additional hydrothermal flows e.g. through fault zones may increase the subglacial melting rates. In this contribution, we will present results from a case study in the Southern North Sea. A 2D seismic section includes two tunnel valleys above salt structures. To model the state prior to erosion and sedimentation during and after the Quaternary glaciations, the Quaternary strata is replaced by strata with the same physical properties and thicknesses than the Paleocene to Miocene strata. Simulation runs with SHEMAT-Suite calculated the ... |
format |
Conference Object |
author |
Bodenburg, Sascha Reiche, Sönke Blachut, Wojciech Hübscher, Christian Kowalski, Julia |
author_facet |
Bodenburg, Sascha Reiche, Sönke Blachut, Wojciech Hübscher, Christian Kowalski, Julia |
author_sort |
Bodenburg, Sascha |
title |
Computational Modelling of Coupled Heat Transport between the Heterogeneous Earth and an Overlying Ice Sheet |
title_short |
Computational Modelling of Coupled Heat Transport between the Heterogeneous Earth and an Overlying Ice Sheet |
title_full |
Computational Modelling of Coupled Heat Transport between the Heterogeneous Earth and an Overlying Ice Sheet |
title_fullStr |
Computational Modelling of Coupled Heat Transport between the Heterogeneous Earth and an Overlying Ice Sheet |
title_full_unstemmed |
Computational Modelling of Coupled Heat Transport between the Heterogeneous Earth and an Overlying Ice Sheet |
title_sort |
computational modelling of coupled heat transport between the heterogeneous earth and an overlying ice sheet |
publishDate |
2021 |
url |
https://doi.org/10.23689/fidgeo-3963 http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/8303 |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_relation |
81. Jahrestagung der Deutschen Geophysikalischen Gesellschaft (DGG), 01.-05.03.2021, Kiel doi:10.23689/fidgeo-3963 http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/8303 |
op_rights |
CC::CC BY 4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.23689/fidgeo-3963 |
_version_ |
1766031173876711424 |