Role of poroelasticity during the early postseismic deformation of the 2010 Maule megathrust earthquake
- Megathrust earthquakes impose changes of differential stress and pore pressure in the lithosphere-asthenosphere system that are transiently relaxed during the postseismic period primarily due to afterslip, viscoelastic and poroelastic processes. Especially during the early postseismic phase, however, the relative contribution of these processes to the observed surface deformation is unclear. To investigate this, we use geodetic data collected in the first 48 days following the 2010 Maule earthquake and a poro-viscoelastic forward model combined with an afterslip inversion. This model approach fits the geodetic data 14% better than a pure elastic model. Particularly near the region of maximum coseismic slip, the predicted surface poroelastic uplift pattern explains well the observations. If poroelasticity is neglected, the spatial afterslip distribution is locally altered by up to +/- 40%. Moreover, we find that shallow crustal aftershocks mostly occur in regions of increased postseismic pore-pressure changes, indicating thatMegathrust earthquakes impose changes of differential stress and pore pressure in the lithosphere-asthenosphere system that are transiently relaxed during the postseismic period primarily due to afterslip, viscoelastic and poroelastic processes. Especially during the early postseismic phase, however, the relative contribution of these processes to the observed surface deformation is unclear. To investigate this, we use geodetic data collected in the first 48 days following the 2010 Maule earthquake and a poro-viscoelastic forward model combined with an afterslip inversion. This model approach fits the geodetic data 14% better than a pure elastic model. Particularly near the region of maximum coseismic slip, the predicted surface poroelastic uplift pattern explains well the observations. If poroelasticity is neglected, the spatial afterslip distribution is locally altered by up to +/- 40%. Moreover, we find that shallow crustal aftershocks mostly occur in regions of increased postseismic pore-pressure changes, indicating that both processes might be mechanically coupled.…
Author details: | Carlos PeñaORCiD, Sabrina MetzgerORCiDGND, Oliver HeidbachORCiDGND, Jonathan BedfordORCiDGND, Bodo BookhagenORCiDGND, Marcos Moreno, Onno OnckenGND, Fabrice CottonORCiDGND |
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DOI: | https://doi.org/10.1029/2022GL098144 |
ISSN: | 0094-8276 |
ISSN: | 1944-8007 |
Title of parent work (English): | Geophysical research letters |
Publisher: | Wiley |
Place of publishing: | Hoboken, NJ |
Publication type: | Article |
Language: | English |
Date of first publication: | 2022/04/26 |
Publication year: | 2022 |
Release date: | 2024/05/31 |
Tag: | Chilean subduction zone; GNSS; InSAR; afterslip inversion; poroelasticity; power-law rheology |
Volume: | 49 |
Issue: | 9 |
Article number: | e2022GL098144 |
Number of pages: | 11 |
Funding institution: | Initiative and Networking Fund of the Helmholtz Association; University; of Potsdam through the Bridge Program; ANID PIA Anillo [ACT192169];; Millennium Scientific Initiative [NC160025]; National Research Center; for Integrated Natural Disaster Management (CIGIDEN); [CONICYT/FONDAP/15110017] |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
DDC classification: | 5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften |
Peer review: | Referiert |
Publishing method: | Open Access / Hybrid Open-Access |
License (German): | CC-BY - Namensnennung 4.0 International |