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Spatio-temporal variability of subduction zone seismicity from 2D and 3D seismo-thermo-mechanical models

English title Spatio-temporal variability of subduction zone seismicity from 2D and 3D seismo-thermo-mechanical modelses
Applicant Gerya Taras
Number 169880
Funding scheme Project funding
Research institution Institut für Geophysik ETH Zürich
Institution of higher education ETH Zurich - ETHZ
Main discipline Geophysics
Start/End 01.04.2017 - 31.03.2018
Approved amount 96'322.00
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Keywords (5)

subduction zones; seismo-thermo-mechanical models; megathrust earthquakes; earthquake source physics; off-megathrust seismicity

Lay Summary (German)

Lead
Subduktionszonen, in denen eine tektonische Platte entlang der Megaüberschiebungsverwerfung unter eine andere geschoben wird, generierten die stärksten Erdbeben im letzten Jahrhundert. Unser Verständnis starker Erdbeben ist eingeschränkt aufgrund fehlender Beobachtungen und limitierter Computermodelle. Wir entwickeln ein Computermodell weiter für die Identifizierung lang dauernder und grossräumiger Prozesse, welche die Entstehung von Erdbeben entscheidend beeinflussen.
Lay summary

Wir setzen das SNF Forschungsprojekt Nr. 153524 fort, welches das Ziel verfolgte, mit Computermodellen Erdbeben zusammen mit der Entstehung von Subduktionszonen zu simulieren. Wir entwickeln unsere Methode weiter, um  Erdbeben zeitlich und räumlich in einem zwei- und dreidimensionalem Modell aufzulösen. Dazu benutzen wir ein etabliertes, auf Laboruntersuchungen basiertes Reibungskonzept. Mit dem weiterentwickelten und optimierten Modell untersuchen wir in Parameter- und Fallstudien lang dauernde und grossräumiger Prozesse in den beiden Platten (die Zugkraft, Unebenheit und Sedimentdicke der abtauchenden Platte und Deformationsstatus der oberen Platte) und deren Einfluss auf die Entstehung von grossen Erdbeben und auf die Entwicklung des Verfwerfungssystems.  

In diesem Projekt  arbeiten wir daran, die enorm unterschiedlichen Zeit- und Längenskalen in den Fragestellungen der Geodynamik und der Erdbebenphysik zu überbrücken. Ein erfolgreicher Abschluss dieses Projekts wird eine Forschungsrichtung an der Schnittstelle dieser Wissenschaftsgemeinden ermöglichen. Die Ergebnisse aus dieser Forschung werden auf längerer Sicht Lücken in der für die Gesellschaft wichtigen Gefährdungseinschätzung schliessen.

 

Direct link to Lay Summary Last update: 08.02.2017

Responsible applicant and co-applicants

Employees

Publications

Publication
Seismic behaviour of mountain belts controlled by plate convergence rate
Luca Dal Zilio Ylona van Dinther Taras V. Gerya Casper C. Pranger (2018), Seismic behaviour of mountain belts controlled by plate convergence rate, in Earth and Planetary Science Letters, 482, 81-92.
Crustal rheology controls on the Tibetan plateau formation during India-Asia convergence
Lin Chen Fabio A. Capitanio Lijun Liu Taras V. Gerya (2017), Crustal rheology controls on the Tibetan plateau formation during India-Asia convergence, in Nature Communications, 8, 15992.
Toward 4D modeling of orogenic belts: Example from the transpressive Zagros Fold Belt
Jonas B. Ruh Taras Gerya Jean-Pierre Burg (2017), Toward 4D modeling of orogenic belts: Example from the transpressive Zagros Fold Belt, in Tectonophysics, 702, 82-89.
An invariant rate- and state-dependent friction formulation for visco-elasto-plastic earthquake cycle simulations
Herrendörfer R. Gerya T. van Dinther Y., An invariant rate- and state-dependent friction formulation for visco-elasto-plastic earthquake cycle simulations, in Journal of Geophysical Research, xxx.
Dynamics of terrane accretion during seaward continental drifting and oceanic subduction: Numerical modeling and implications for the Jurassic crustal growth of the Lhasa Terrane, Tibet
Shao-Hua Yang Zhong-Hai Li Taras Gerya Zhi-Qin Xue Yao-Lin Shi, Dynamics of terrane accretion during seaward continental drifting and oceanic subduction: Numerical modeling and implications for the Jurassic crustal growth of the Lhasa Terrane, Tibet, in Tectonophysics, xxx.
Subduction initiation in nature and models: A review
Robert J. Sterna Taras Gerya, Subduction initiation in nature and models: A review, in Tectonophysics, xxx.

Collaboration

Group / person Country
Types of collaboration
Prof. Dr. Andreas Fichtner, ETH-Zurich Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
Dr. Jonas Ruh, CSIC Institut de Cincies del Mar, Barcelona Spain (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Prof. Chen Lin, State Key Laboratory of Lithospheric Evolution, Chinese Academy of Sciences China (Asia)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Prof. Zhong-Hai Li, Key Laboratory of Continental Tectonics and Dynamics, Chinese Academy of Sci China (Asia)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Dr. David May, ETH-Zurich Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Dr. Laetitia Le Pourhiet, University of Pierre and Marie Curie (Paris VI) France (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Prof. Robert Stern, University of Texas, Dallas United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
AGU Fall Meeting 2017 Talk given at a conference Seismic and Aseismic Slip on Mature and Evolving Faults Simulated with Rate-and-State Friction in a Continuum 11.12.2017 New Orleans, United States of America Herrendörfer Robert; van Dinther Ylona; Gerya Taras;
EGU General Assembly 2017 Talk given at a conference Earthquakes as plastic failure on spontaneously evolving faults 23.04.2017 Vienna, Austria van Dinther Ylona; Pranger Casper; Herrendörfer Robert; Gerya Taras;
EGU General Assembly 2017 Talk given at a conference Simulating spontaneous aseismic and seismic slip events on evolving faults 23.04.2017 Vienna, Austria van Dinther Ylona; Gerya Taras; Herrendörfer Robert; Pranger Casper;


Associated projects

Number Title Start Funding scheme
125274 Genesis of mega-thrust earthquakes events at convergent plate boundaries: 3D modelling of seismic coupling combining geodynamic and earthquake-faulting models 01.06.2009 Project funding
182069 Numerical modelling of rheological controls for nucleation, evolution and seismicity of tectonic plate boundaries 01.02.2019 Project funding
153524 Spatio-temporal variability of subduction zone seismicity from seismo-thermo-mechanical models 01.04.2014 Project funding

Abstract

In 2014 SNSF funded project 153524 to support PhD candidate Robert Herrendörfer. The goal of the project was to delineate how relevant physical parameters lead to spatio-temporal variability of subduction zone seismicity. We proposed a systematic parameter study involving three key objectives, maintained in this proposal.In key objective 1 we analyzed spatial variability of megathrust seismicity and demonstrated the control of seismogenic zone width on supercycles in Nature Geoscience (Herrendörfer et al., 2015). A stress evolution mechanism was observed to event-wise increase earthquakes up to thus far not observed super-events for larger than average width subduction zones, such as the Antilles or Kamchatka. In a co-authored manuscript, we found that a subduction segments maximum magnitude is not affected by subduction velocity, as opposed to suggestions from time-limited natural observations (Corbi et al., to be submitted April 2016).Subsequently, we undertook the four numerical challenges delineated in our proposal (adaptive time stepping, 3D, wave propagation, and rate-and-state friction). Their novel implementation is nearly finished, but the time needed for 2D and 3D numerical code development and validation was distinctly underestimated. Thus creating the need for one-year funding extension for Robert Herrendörfer. As originally planned, the very challenging 3D seismo-thermo-mechanical (STM) code development has been undertaken full-time by a second PhD student (Casper Pranger), who was originally funded for a maximum of three years by EU project ZIP. To successfully finalize and exploit his still on-going 3D code development efforts and to be able to accomplish all three objectives of our original SNSF project, we also request one-year funding for this second PhD student.In key objective 2 we analyzed the spatio-temporal variability of on- and off-megathrust seismicity. To resolve the temporal interaction, including aseismic and slow slip, we implemented rate-and-state friction and adaptive time stepping. Its validation is almost finished and we are currently assessing the role of off-megathrust rate-and-state friction parameters. We further plan to analyze the role of sea floor roughness and slab pull.In key objective 3 we will extend our results to 3D upon finishing the development of a MPI-parallel, dynamic 3D STM code this year. This allows us to truly bridge geodynamic and seismic time scales and answer our longstanding challenges more convincingly. Lateral propagation is particularly important for the to be analyzed sea floor roughness and upper plate strain. Besides assessing these physical mechanisms for self-consistent megathrust segmentation, we will deliver two key deliverables by assessing seismicity in northeastern Japan in 3D and updating our initiated global map of long-term seismicity regimes (Herrendörfer et al., 2015).This continuation proposal, requesting one-year salary for 2 PhD students, is submitted to successfully finalize this innovative and interdisciplinary research, which gained momentum by almost overcoming the major numerical challenges. These developments will be published in high-level two papers this year. With one-year extension for both PhD students, we can enter the production stage and achieve all original project objectives through four high-impact papers. Both PhD students will be then able to successfully defend their PhD theses. Beyond this proposal, the adequately executed developments could trigger a snowball effect in which the 8-person informal STM group, led by the co-applicants, can distinctly impact and assist the geodynamic and seismological communities and ultimately influence the seismic hazard community and society.
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