seismo-thermo-mechanical models; megathrust earthquakes; subduction zones; off-megathrust seismicity; earthquake source physics
Gerya Taras (2019), Introduction to Numerical Geodynamic Modelling
, Cambridge University Press, Cambridge, United Kingdom.
Herrendörfer Robert, Gerya Taras, van Dinther Ylona (2018), An Invariant Rate- and State-Dependent Friction Formulation for Viscoeastoplastic Earthquake Cycle Simulations, in Journal of Geophysical Research: Solid Earth
, 123(6), 5018-5051.
Gerya Taras (2016), Origin, evolution, seismicity and models of oceanic and continental transform boundaries., in Duarte J. Schellart W. (ed.), John Wiley & Sons, American Geophysical Union, 39.
Malatesta Cristina, Gerya Taras, Crispini Laura, Federico Laura, Capponi Giovanni (2016), Interplate deformation at early-stage oblique subduction: 3-D thermomechanical numerical modelingThree-Dimensional Modeling of Interplate Deformation, in Tectonics
, 35(7), 1610-1625.
Gerya T. (2015), Tectonic overpressure and underpressure in lithospheric tectonics and metamorphism, in Journal of Metamorphic Geology
, 33(8), 785-800.
Herrendoerfer R. van Dinther Y. Gerya T. Dalguer L. A. (2015), Earthquake supercycle in subduction zones controlled by the width of the seismogenic zone, in Nature Geoscience
, 8, 471-474.
Corbi F. Herrendoerfer R. Funiciello F. Van Dinther Y., Controls of seismogenic zone width and subduction velocity on interplate seismicity: insights from analog and numerical models, in Geophysical Research Letters
The catastrophic occurrence of the 2011 M9.0 Tohoku and 2004 M9.2 Sumatra earthquakes illustrated the disastrous human and economic impact of megathrust earthquakes (Mw>8.5) and our limited physical understanding of where and when these megathrust earthquakes may strike. The necessary improvement of long-term seismic hazard assessment requires a better physical understanding of the spatiotemporal variability of subduction zone seismicity. Numerical models have the potential to overcome the main obstacle that limits our understanding: restricted, direct observations in both time and space. One promising numerical modeling approach is the recently developed seismo-thermo-mechanical modeling approach (STM). This continuum-mechanics based, visco-elasto-plastic approach combines the long-term subduction dynamics and associated short-term seismicity in a physically consistent manner. Additional advantages of this STM approach include the physically-consistent emergence of rupture paths, both on- and off-megathrust, and the inclusion of three key ingredients for seismic cycling; rate-dependent friction, slow tectonic loading and visco-elastic relaxation. This with SNSF-support developed state-of-the-art methodology (SNSF-project 200021-125274 4) is here proposed to be explored and applied by a highly qualified PhD student. He will be supervised by the original team of distinguished, complementary expertise in geodynamic numerical modeling, earthquake seismology and seismic hazard assessment. The objective of this multi-disciplinary research is to delineate the role of the relevant physical parameters characterizing subduction zones that are responsible for the spatiotemporal variability of subduction zone seismicity, both on- and off- the megathrust. Through a systematic parameter study, this research intends to provide a physical basis for answering the key seismological question along which subduction zone segments megathrust earthquakes are more likely to happen. By step-wise increasing the complexity of the model setup, we will subsequently analyze a) the 2D spatial variability of megathrust seismicity as a function of subduction velocity, slab age, sediment thickness, overriding plate Moho depth, and serpentinite thickness, b) the 2D spatiotemporal variability of physically-consistently evolving outerrise and splay faulting events as a function of the first three before mentioned parameters, and c) extend these results to three dimensions and analyze the role of upper plate strain (UPS) and sediment thickness and apply these results to analyze the long-term seismicity in northeastern Japan. These interseismic, coseismic and postseismic results will be compared to a by our collaborators developed global database, which includes both these geodynamic properties and different classes of megathrust, oceanic slab and overriding plate seismicity data. By combining these anticipated results, we propose to deliver a global map highlighting the potential modelling-based long-term seismicity regimes of the 62 subduction zone segments spanning the globe. This map could latter be used for long-term seismic hazard assessment purposes. To accomplish this we request funding to for three years cover one PhD student and related research costs.