Inferring mantle viscosity through data assimilation of relative sea level observations in a glacial isostatic adjustment model
We suggest to apply data assimilation in glacial isostatic adjustment (GIA) to constrain the mantle viscosity structure based on sea level observations. We apply the Parallel Data Assimilation Framework (PDAF) to assimilate sea level data into the time-domain spectral-finite element code VILMA in or...
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ftoceanrep:oai:oceanrep.geomar.de:55527 2023-05-15T16:12:10+02:00 Inferring mantle viscosity through data assimilation of relative sea level observations in a glacial isostatic adjustment model Schachtschneider, Reyko Saynisch-Wagner, Jan Klemann, Volker Bagge, Meike Thomas, Maik 2021 text https://oceanrep.geomar.de/id/eprint/55527/ https://oceanrep.geomar.de/id/eprint/55527/1/EGU21_1261_presentation.pdf https://doi.org/10.5194/egusphere-egu21-1261 en eng https://oceanrep.geomar.de/id/eprint/55527/1/EGU21_1261_presentation.pdf Schachtschneider, R. , Saynisch-Wagner, J., Klemann, V., Bagge, M. and Thomas, M. (2021) Inferring mantle viscosity through data assimilation of relative sea level observations in a glacial isostatic adjustment model. Open Access [PICO] In: EGU General Assembly 2021. , 19.-30.03.2021, Online . DOI 10.5194/egusphere-egu21-1261 <https://doi.org/10.5194/egusphere-egu21-1261>. doi:10.5194/egusphere-egu21-1261 cc_by_4.0 info:eu-repo/semantics/openAccess Conference or Workshop Item NonPeerReviewed 2021 ftoceanrep https://doi.org/10.5194/egusphere-egu21-1261 2023-04-07T16:01:26Z We suggest to apply data assimilation in glacial isostatic adjustment (GIA) to constrain the mantle viscosity structure based on sea level observations. We apply the Parallel Data Assimilation Framework (PDAF) to assimilate sea level data into the time-domain spectral-finite element code VILMA in order to obtain better estimates of the mantle viscosity structure. In a first step, we reduce to a spherically symmetric earth structure and prescribe the glaciation history. A particle filter is used to propagate an ensemble of models in time. At epochs when observations are available, each particle's performance is estimated and the particles are resampled based on their performance to form a new ensemble that better resembles the true viscosity distribution. Using this algorithm, we show the ability to recover mantle viscosities from a set of synthetic relative sea level observations. Those synthetic observations are obtained from a reference run with a given viscosity structure that defines the target viscosity values in our experiments. The viscosity estimation is applied to a three-layer model with an elastic lithosphere and two mantle layers, and to a multi-layer model with a smoother viscosity profile. We use various subsets of realistic observation locations (e.g. only observations from Fennoscandia) and show that it is possible to obtain the target viscosity values in those cases. We also vary the time from which observations are available to evolve the test cases towards a realistic scenario for the availability of relative sea level observations. The most relevant cases start at 26.5ka BP and at 10ka BP as they mark the beginning of the maximum glaciation and the end of deglaciation with a larger amount of observations following, respectively, and end at present day. Conference Object Fennoscandia OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
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Open Polar |
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OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
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ftoceanrep |
language |
English |
description |
We suggest to apply data assimilation in glacial isostatic adjustment (GIA) to constrain the mantle viscosity structure based on sea level observations. We apply the Parallel Data Assimilation Framework (PDAF) to assimilate sea level data into the time-domain spectral-finite element code VILMA in order to obtain better estimates of the mantle viscosity structure. In a first step, we reduce to a spherically symmetric earth structure and prescribe the glaciation history. A particle filter is used to propagate an ensemble of models in time. At epochs when observations are available, each particle's performance is estimated and the particles are resampled based on their performance to form a new ensemble that better resembles the true viscosity distribution. Using this algorithm, we show the ability to recover mantle viscosities from a set of synthetic relative sea level observations. Those synthetic observations are obtained from a reference run with a given viscosity structure that defines the target viscosity values in our experiments. The viscosity estimation is applied to a three-layer model with an elastic lithosphere and two mantle layers, and to a multi-layer model with a smoother viscosity profile. We use various subsets of realistic observation locations (e.g. only observations from Fennoscandia) and show that it is possible to obtain the target viscosity values in those cases. We also vary the time from which observations are available to evolve the test cases towards a realistic scenario for the availability of relative sea level observations. The most relevant cases start at 26.5ka BP and at 10ka BP as they mark the beginning of the maximum glaciation and the end of deglaciation with a larger amount of observations following, respectively, and end at present day. |
format |
Conference Object |
author |
Schachtschneider, Reyko Saynisch-Wagner, Jan Klemann, Volker Bagge, Meike Thomas, Maik |
spellingShingle |
Schachtschneider, Reyko Saynisch-Wagner, Jan Klemann, Volker Bagge, Meike Thomas, Maik Inferring mantle viscosity through data assimilation of relative sea level observations in a glacial isostatic adjustment model |
author_facet |
Schachtschneider, Reyko Saynisch-Wagner, Jan Klemann, Volker Bagge, Meike Thomas, Maik |
author_sort |
Schachtschneider, Reyko |
title |
Inferring mantle viscosity through data assimilation of relative sea level observations in a glacial isostatic adjustment model |
title_short |
Inferring mantle viscosity through data assimilation of relative sea level observations in a glacial isostatic adjustment model |
title_full |
Inferring mantle viscosity through data assimilation of relative sea level observations in a glacial isostatic adjustment model |
title_fullStr |
Inferring mantle viscosity through data assimilation of relative sea level observations in a glacial isostatic adjustment model |
title_full_unstemmed |
Inferring mantle viscosity through data assimilation of relative sea level observations in a glacial isostatic adjustment model |
title_sort |
inferring mantle viscosity through data assimilation of relative sea level observations in a glacial isostatic adjustment model |
publishDate |
2021 |
url |
https://oceanrep.geomar.de/id/eprint/55527/ https://oceanrep.geomar.de/id/eprint/55527/1/EGU21_1261_presentation.pdf https://doi.org/10.5194/egusphere-egu21-1261 |
genre |
Fennoscandia |
genre_facet |
Fennoscandia |
op_relation |
https://oceanrep.geomar.de/id/eprint/55527/1/EGU21_1261_presentation.pdf Schachtschneider, R. , Saynisch-Wagner, J., Klemann, V., Bagge, M. and Thomas, M. (2021) Inferring mantle viscosity through data assimilation of relative sea level observations in a glacial isostatic adjustment model. Open Access [PICO] In: EGU General Assembly 2021. , 19.-30.03.2021, Online . DOI 10.5194/egusphere-egu21-1261 <https://doi.org/10.5194/egusphere-egu21-1261>. doi:10.5194/egusphere-egu21-1261 |
op_rights |
cc_by_4.0 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/egusphere-egu21-1261 |
_version_ |
1765997409571176448 |