Role of Lower Crust in the Postseismic Deformation of the 2010 Maule Earthquake: Insights from a Model with Power-Law Rheology
- The surface deformation associated with the 2010 M-w 8.8 Maule earthquake in Chile was recorded in great detail before, during and after the event. The high data quality of the continuous GPS (cGPS) observations has facilitated a number of studies that model the postseismic deformation signal with a combination of relocking, afterslip and viscoelastic relaxation using linear rheology for the upper mantle. Here, we investigate the impact of using linear Maxwell or power-law rheology with a 2D geomechanical-numerical model to better understand the relative importance of the different processes that control the postseismic deformation signal. Our model results reveal that, in particular, the modeled cumulative vertical postseismic deformation pattern in the near field (< 300 km from the trench) is very sensitive to the location of maximum afterslip and choice of rheology. In the model with power-law rheology, the afterslip maximum is located at 20-35 km rather than > 50 km depth as suggested in previous studies. The explanation for thisThe surface deformation associated with the 2010 M-w 8.8 Maule earthquake in Chile was recorded in great detail before, during and after the event. The high data quality of the continuous GPS (cGPS) observations has facilitated a number of studies that model the postseismic deformation signal with a combination of relocking, afterslip and viscoelastic relaxation using linear rheology for the upper mantle. Here, we investigate the impact of using linear Maxwell or power-law rheology with a 2D geomechanical-numerical model to better understand the relative importance of the different processes that control the postseismic deformation signal. Our model results reveal that, in particular, the modeled cumulative vertical postseismic deformation pattern in the near field (< 300 km from the trench) is very sensitive to the location of maximum afterslip and choice of rheology. In the model with power-law rheology, the afterslip maximum is located at 20-35 km rather than > 50 km depth as suggested in previous studies. The explanation for this difference is that in the model with power-law rheology the relaxation of coseismically imposed differential stresses occurs mainly in the lower crust. However, even though the model with power-law rheology probably has more potential to explain the vertical postseismic signal in the near field, the uncertainty of the applied temperature field is substantial, and this needs further investigations and improvements.…
Author details: | Carlos PenaORCiD, Oliver HeidbachORCiDGND, Marcos MorenoORCiD, Jonathan BedfordGND, Moritz 0. ZieglerORCiDGND, Andres Ollero TassaraORCiDGND, Onno OnckenORCiDGND |
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DOI: | https://doi.org/10.1007/s00024-018-02090-3 |
ISSN: | 0033-4553 |
ISSN: | 1420-9136 |
Title of parent work (English): | Pure and applied geophysics |
Publisher: | Springer |
Place of publishing: | Basel |
Publication type: | Article |
Language: | English |
Date of first publication: | 2019/01/22 |
Publication year: | 2019 |
Release date: | 2020/11/15 |
Volume: | 176 |
Issue: | 9 |
Number of pages: | 16 |
First page: | 3913 |
Last Page: | 3928 |
Funding institution: | German Academic Exchange Service (DAAD)Deutscher Akademischer Austausch Dienst (DAAD); National Commission for Scientific and Technological Research (CONICYT-Becas Chile); German Science Foundation (DFG)German Research Foundation (DFG) [MO-2310/3-1]; Chilean National Fund for Development of Science and Technology (FONDECYT)Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT)CONICYT FONDECYT [1181479]; Millennium Scientific Initiative (ICM) grant [NC160025]; National Research Center for Integrated Natural Disaster Management (CIGIDEN), CONICYT/FONDAP [15110017]; National Fund for Scientific and Technological Development, FONDECYTComision Nacional de Investigacion Cientifica y Tecnologica (CONICYT)CONICYT FONDECYT [1151175] |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
DDC classification: | 5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften |