An approach for constraining mantle viscosities through assimilation of palaeo sea level data into a glacial isostatic adjustment model
Glacial isostatic adjustment is largely governed by the rheological properties of the Earth's mantle. Large mass redistributions in the ocean–cryosphere system and the subsequent response of the viscoelastic Earth have led to dramatic sea level changes in the past. This process is ongoing, and...
Published in: | Nonlinear Processes in Geophysics |
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Copernicus Publications (EGU)
2022
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Online Access: | https://oceanrep.geomar.de/id/eprint/55503/ https://oceanrep.geomar.de/id/eprint/55503/1/npg_29_53_2022.pdf https://doi.org/10.5194/npg-29-53-2022 |
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ftoceanrep:oai:oceanrep.geomar.de:55503 2023-05-15T16:12:11+02:00 An approach for constraining mantle viscosities through assimilation of palaeo sea level data into a glacial isostatic adjustment model Schachtschneider, Reyko Saynisch-Wagner, Jan Klemann, Volker Bagge, Meike Thomas, Maik 2022-02-17 text https://oceanrep.geomar.de/id/eprint/55503/ https://oceanrep.geomar.de/id/eprint/55503/1/npg_29_53_2022.pdf https://doi.org/10.5194/npg-29-53-2022 en eng Copernicus Publications (EGU) https://oceanrep.geomar.de/id/eprint/55503/1/npg_29_53_2022.pdf Schachtschneider, R., Saynisch-Wagner, J., Klemann, V., Bagge, M. and Thomas, M. (2022) An approach for constraining mantle viscosities through assimilation of palaeo sea level data into a glacial isostatic adjustment model. Open Access Nonlinear Processes in Geophysics, 29 (1). pp. 53-75. DOI 10.5194/npg-29-53-2022 <https://doi.org/10.5194/npg-29-53-2022>. doi:10.5194/npg-29-53-2022 cc_by_4.0 info:eu-repo/semantics/openAccess Article PeerReviewed 2022 ftoceanrep https://doi.org/10.5194/npg-29-53-2022 2023-04-07T16:01:26Z Glacial isostatic adjustment is largely governed by the rheological properties of the Earth's mantle. Large mass redistributions in the ocean–cryosphere system and the subsequent response of the viscoelastic Earth have led to dramatic sea level changes in the past. This process is ongoing, and in order to understand and predict current and future sea level changes, the knowledge of mantle properties such as viscosity is essential. In this study, we present a method to obtain estimates of mantle viscosities by the assimilation of relative sea level rates of change into a viscoelastic model of the lithosphere and mantle. We set up a particle filter with probabilistic resampling. In an identical twin experiment, we show that mantle viscosities can be recovered in a glacial isostatic adjustment model of a simple three-layer Earth structure consisting of an elastic lithosphere and two mantle layers of different viscosity. We investigate the ensemble behaviour on different parameters in the following three set-ups: (1) global observations data set since last glacial maximum with different ensemble initialisations and observation uncertainties, (2) regional observations from Fennoscandia or Laurentide/Greenland only, and (3) limiting the observation period to 10 ka until the present. We show that the recovery is successful in all cases if the target parameter values are properly sampled by the initial ensemble probability distribution. This even includes cases in which the target viscosity values are located far in the tail of the initial ensemble probability distribution. Experiments show that the method is successful if enough near-field observations are available. This makes it work best for a period after substantial deglaciation until the present when the number of sea level indicators is relatively high. Article in Journal/Newspaper Fennoscandia Greenland OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Greenland Nonlinear Processes in Geophysics 29 1 53 75 |
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Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
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ftoceanrep |
language |
English |
description |
Glacial isostatic adjustment is largely governed by the rheological properties of the Earth's mantle. Large mass redistributions in the ocean–cryosphere system and the subsequent response of the viscoelastic Earth have led to dramatic sea level changes in the past. This process is ongoing, and in order to understand and predict current and future sea level changes, the knowledge of mantle properties such as viscosity is essential. In this study, we present a method to obtain estimates of mantle viscosities by the assimilation of relative sea level rates of change into a viscoelastic model of the lithosphere and mantle. We set up a particle filter with probabilistic resampling. In an identical twin experiment, we show that mantle viscosities can be recovered in a glacial isostatic adjustment model of a simple three-layer Earth structure consisting of an elastic lithosphere and two mantle layers of different viscosity. We investigate the ensemble behaviour on different parameters in the following three set-ups: (1) global observations data set since last glacial maximum with different ensemble initialisations and observation uncertainties, (2) regional observations from Fennoscandia or Laurentide/Greenland only, and (3) limiting the observation period to 10 ka until the present. We show that the recovery is successful in all cases if the target parameter values are properly sampled by the initial ensemble probability distribution. This even includes cases in which the target viscosity values are located far in the tail of the initial ensemble probability distribution. Experiments show that the method is successful if enough near-field observations are available. This makes it work best for a period after substantial deglaciation until the present when the number of sea level indicators is relatively high. |
format |
Article in Journal/Newspaper |
author |
Schachtschneider, Reyko Saynisch-Wagner, Jan Klemann, Volker Bagge, Meike Thomas, Maik |
spellingShingle |
Schachtschneider, Reyko Saynisch-Wagner, Jan Klemann, Volker Bagge, Meike Thomas, Maik An approach for constraining mantle viscosities through assimilation of palaeo sea level data into a glacial isostatic adjustment model |
author_facet |
Schachtschneider, Reyko Saynisch-Wagner, Jan Klemann, Volker Bagge, Meike Thomas, Maik |
author_sort |
Schachtschneider, Reyko |
title |
An approach for constraining mantle viscosities through assimilation of palaeo sea level data into a glacial isostatic adjustment model |
title_short |
An approach for constraining mantle viscosities through assimilation of palaeo sea level data into a glacial isostatic adjustment model |
title_full |
An approach for constraining mantle viscosities through assimilation of palaeo sea level data into a glacial isostatic adjustment model |
title_fullStr |
An approach for constraining mantle viscosities through assimilation of palaeo sea level data into a glacial isostatic adjustment model |
title_full_unstemmed |
An approach for constraining mantle viscosities through assimilation of palaeo sea level data into a glacial isostatic adjustment model |
title_sort |
approach for constraining mantle viscosities through assimilation of palaeo sea level data into a glacial isostatic adjustment model |
publisher |
Copernicus Publications (EGU) |
publishDate |
2022 |
url |
https://oceanrep.geomar.de/id/eprint/55503/ https://oceanrep.geomar.de/id/eprint/55503/1/npg_29_53_2022.pdf https://doi.org/10.5194/npg-29-53-2022 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Fennoscandia Greenland |
genre_facet |
Fennoscandia Greenland |
op_relation |
https://oceanrep.geomar.de/id/eprint/55503/1/npg_29_53_2022.pdf Schachtschneider, R., Saynisch-Wagner, J., Klemann, V., Bagge, M. and Thomas, M. (2022) An approach for constraining mantle viscosities through assimilation of palaeo sea level data into a glacial isostatic adjustment model. Open Access Nonlinear Processes in Geophysics, 29 (1). pp. 53-75. DOI 10.5194/npg-29-53-2022 <https://doi.org/10.5194/npg-29-53-2022>. doi:10.5194/npg-29-53-2022 |
op_rights |
cc_by_4.0 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/npg-29-53-2022 |
container_title |
Nonlinear Processes in Geophysics |
container_volume |
29 |
container_issue |
1 |
container_start_page |
53 |
op_container_end_page |
75 |
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1765997432514019328 |