posted on 2023-05-20, 11:46authored byZwinger, T, Grace Nield, Ruokolainen, J, Matt KingMatt King
We present a new, open-source viscoelastic solid earth deformation model, Elmer/Earth. Using the multi-physics finite-element package Elmer, a model to compute viscoelastic material deformation has been implemented into the existing linear elasticity solver routine. Unlike approaches often implemented in engineering codes, our solver accounts for the restoring force of buoyancy within a system of layers with depth-varying density. It does this by directly integrating the solution of the system rather than by applying stress-jump conditions in the form of Winkler foundations on inter-layer boundaries, as is usually needed when solving the minimization problem given by the stress divergence in commercial codes. We benchmarked the new model with results from a commercial finite-element engineering package (ABAQUS, v2018) and another open-source code that uses viscoelastic normal mode theory, TABOO, using a flat-earth setup loaded by a cylindrical disc of 100 km in diameter and 100 m in height at the density of ice. Evaluating the differences in predicted surface deformation at the centre of the load and two distinctive distances (100 and 200 km), average deviations of 7 and 2.7 cm of Elmer/Earth results to ABAQUS and TABOO, respectively, were observed. In view of more than 100 cm maximum vertical deformation and the different numerical methods and parameters, these are very encouraging results. Elmer is set up as a highly scalable parallel code and distributed under the (L)GPL license, meaning that large-scale computations can be made without any licensing restrictions. Scaling figures presented in this paper show good parallel performance of the new model. Additionally, the high-fidelity ice-sheet code Elmer/Ice utilizes the same source base as Elmer and thereby the new model opens the way to undertaking high-resolution coupled ice-flow–solid-earth deformation simulations, which are required for robust projections of future sea-level rise and glacial isostatic adjustment.
Funding
Australian Research Council
History
Publication title
Geoscientific Model Development
Volume
13
Pagination
1155-1164
ISSN
1991-959X
Department/School
School of Geography, Planning and Spatial Sciences
Publisher
Copernicus GmbH
Place of publication
Germany
Rights statement
Copyright 2020 the authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/