scholarly journals Cascadia megathrust earthquake rupture model constrained by geodetic fault locking

2020 ◽  
Author(s):  
Duo Li ◽  
Yajing Liu
Keyword(s):  
Earthquake Rupture ◽  
Megathrust Earthquake ◽  
Rupture Model ◽  
Fault Locking

scholarly journals Cascadia megathrust earthquake rupture model constrained by geodetic fault locking

2021 ◽  
Vol 379 (2196) ◽  
pp. 20200135 ◽  
Author(s):  
Duo Li ◽  
Yajing Liu
Keyword(s):  
Subduction Zone ◽  
Subduction Zones ◽  
Seismogenic Zone ◽  
Cascadia Subduction Zone ◽  
Earthquake Rupture ◽  
Megathrust Earthquake ◽  
Fracture Dynamics ◽  
Coastal Marine ◽  
Rate And State Friction ◽  
Fault Locking

Paleo-earthquakes along the Cascadia subduction zone inferred from offshore sediments and Japan coastal tsunami deposits approximated to M9+ and ruptured the entire margin. However, due to the lack of modern megathrust earthquake records and general quiescence of subduction fault seismicity, the potential megathrust rupture scenario and influence of downdip limit of the seismogenic zone are still obscure. In this study, we present a numerical simulation of Cascadia subduction zone earthquake sequences in the laboratory-derived rate-and-state friction framework to investigate the potential influence of the geodetic fault locking on the megathrust sequences. We consider the rate-state friction stability parameter constrained by geodetic fault locking models derived from decadal GPS records, tidal gauge and levelling-derived uplift rate data along the Cascadia margin. We incorporate historical coseismic subsidence inferred from coastal marine sediments to validate our coseismic rupture scenarios. Earthquake rupture pattern is strongly controlled by the downdip width of the seismogenic, velocity-weakening zone and by the earthquake nucleation zone size. In our model, along-strike heterogeneous characteristic slip distance is required to generate margin-wide ruptures that result in reasonable agreement between the synthetic and observed coastal subsidence for the AD 1700 Cascadia Mw∼9.0 megathrust rupture. Our results suggest the geodetically inferred fault locking model can provide a useful constraint on earthquake rupture scenarios in subduction zones. This article is part of the theme issue ‘Fracture dynamics of solid materials: from particles to the globe’.

scholarly journals Bayesian inference of earthquake rupture models using polynomial chaos expansion

2018 ◽  
Vol 11 (7) ◽  
pp. 3071-3088 ◽  
Author(s):  
Hugo Cruz-Jiménez ◽  
Guotu Li ◽  
Paul Martin Mai ◽  
Ibrahim Hoteit ◽  
Omar M. Knio
Keyword(s):  
Bayesian Inference ◽  
Surrogate Model ◽  
Polynomial Chaos ◽  
Fault Plane ◽  
Dominant Role ◽  
Prediction Equation ◽  
Peak Ground Velocity ◽  
Earthquake Rupture ◽  
Physical Constraints ◽  
Rupture Model

Abstract. In this paper, we employed polynomial chaos (PC) expansions to understand earthquake rupture model responses to random fault plane properties. A sensitivity analysis based on our PC surrogate model suggests that the hypocenter location plays a dominant role in peak ground velocity (PGV) responses, while elliptical patch properties only show secondary impact. In addition, the PC surrogate model is utilized for Bayesian inference of the most likely underlying fault plane configuration in light of a set of PGV observations from a ground-motion prediction equation (GMPE). A restricted sampling approach is also developed to incorporate additional physical constraints on the fault plane configuration and to increase the sampling efficiency.

scholarly journals Global variations of large megathrust earthquake rupture characteristics

2018 ◽  
Vol 4 (3) ◽  
pp. eaao4915 ◽  
Author(s):  
Lingling Ye ◽  
Hiroo Kanamori ◽  
Thorne Lay
Keyword(s):  
Earthquake Rupture ◽  
Megathrust Earthquake

scholarly journals Linked 3-D modelling of megathrust earthquake-tsunami events: from subduction to tsunami run up

2020 ◽  
Vol 224 (1) ◽  
pp. 487-516 ◽  
Author(s):  
E H Madden ◽  
M Bader ◽  
J Behrens ◽  
Y van Dinther ◽  
A-A Gabriel ◽  
...  
Keyword(s):  
Stress Drop ◽  
Earthquake Source ◽  
Time Dependent ◽  
Tsunami Source ◽  
Earthquake Rupture ◽  
Temporal Behaviour ◽  
Coastal Inundation ◽  
Megathrust Earthquake ◽  
Run Up ◽  
Earthquake Characteristics

SUMMARY How does megathrust earthquake rupture govern tsunami behaviour? Recent modelling advances permit evaluation of the influence of 3-D earthquake dynamics on tsunami genesis, propagation, and coastal inundation. Here, we present and explore a virtual laboratory in which the tsunami source arises from 3-D coseismic seafloor displacements generated by a dynamic earthquake rupture model. This is achieved by linking open-source earthquake and tsunami computational models that follow discontinuous Galerkin schemes and are facilitated by highly optimized parallel algorithms and software. We present three scenarios demonstrating the flexibility and capabilities of linked modelling. In the first two scenarios, we use a dynamic earthquake source including time-dependent spontaneous failure along a 3-D planar fault surrounded by homogeneous rock and depth-dependent, near-lithostatic stresses. We investigate how slip to the trench influences tsunami behaviour by simulating one blind and one surface-breaching rupture. The blind rupture scenario exhibits distinct earthquake characteristics (lower slip, shorter rupture duration, lower stress drop, lower rupture speed), but the tsunami is similar to that from the surface-breaching rupture in run-up and length of impacted coastline. The higher tsunami-generating efficiency of the blind rupture may explain how there are differences in earthquake characteristics between the scenarios, but similarities in tsunami inundation patterns. However, the lower seafloor displacements in the blind rupture result in a smaller displaced volume of water leading to a narrower inundation corridor inland from the coast and a 15 per cent smaller inundation area overall. In the third scenario, the 3-D earthquake model is initialized using a seismo-thermo-mechanical geodynamic model simulating both subduction dynamics and seismic cycles. This ensures that the curved fault geometry, heterogeneous stresses and strength and material structure are consistent with each other and with millions of years of modelled deformation in the subduction channel. These conditions lead to a realistic rupture in terms of velocity and stress drop that is blind, but efficiently generates a tsunami. In all scenarios, comparison with the tsunamis sourced by the time-dependent seafloor displacements, using only the time-independent displacements alters tsunami temporal behaviour, resulting in later tsunami arrival at the coast, but faster coastal inundation. In the scenarios with the surface-breaching and subduction-initialized earthquakes, using the time-independent displacements also overpredicts run-up. In the future, the here presented scenarios may be useful for comparison of alternative dynamic earthquake-tsunami modelling approaches or linking choices, and can be readily developed into more complex applications to study how earthquake source dynamics influence tsunami genesis, propagation and inundation.

Probabilistic Fault Displacement Hazards for the Southern San Andreas Fault Using Scenarios and Empirical Slips

2011 ◽  
Vol 27 (2) ◽  
pp. 293-313 ◽  
Author(s):  
Rui Chen ◽  
Mark D. Petersen
Keyword(s):  
San Andreas Fault ◽  
Probabilistic Method ◽  
Hazard Mapping ◽  
Regression Equations ◽  
Earthquake Rupture ◽  
Hazard Maps ◽  
Mapping Accuracy ◽  
San Andreas ◽  
Rupture Model ◽  
Fault Displacement

We apply a probabilistic method to develop fault displacement hazard maps and profiles for the southern San Andreas Fault. Two slip models are applied: (1) scenario slip, defined by the ShakeOut rupture model, and (2) empirical slip, calculated using regression equations relating global slip to earthquake magnitude and distance along the fault. The hazard is assessed using a range of magnitudes defined by the Uniform California Earthquake Rupture Forecast and the ShakeOut. For hazard mapping we develop a methodology to partition displacement among multiple fault branches based on geological observations. Estimated displacement hazard extends a few kilometers wide in areas of multiple mapped fault branches and poor mapping accuracy. Scenario and empirical displacement hazard differs by a factor of two or three, particularly along the southernmost section of the San Andreas Fault. We recommend the empirical slip model with site-specific geological data to constrain uncertainties for engineering applications.

scholarly journals Bayesian inference of earthquake rupture models using polynomial chaos expansion

2018 ◽  
Author(s):  
Hugo Cruz-Jiménez ◽  
Guotu Li ◽  
Paul Martin Mai ◽  
Ibrahim Hoteit ◽  
Omar M. Knio
Keyword(s):  
Bayesian Inference ◽  
Surrogate Model ◽  
Polynomial Chaos ◽  
Fault Plane ◽  
Dominant Role ◽  
Prediction Equation ◽  
Peak Ground Velocity ◽  
Earthquake Rupture ◽  
Physical Constraints ◽  
Rupture Model

Abstract. In this paper we employed polynomial chaos (PC) expansions to understand earthquake rupture model responses to random fault plane properties. A sensitivity analysis based on our PC surrogate model suggests that the hypocenter location plays a dominant role in peak ground velocity (PGV) responses, while elliptical patch properties only show secondary impact. In addition, the PC surrogate model is utilized for Bayesian inference of the most likely underlying fault plane configuration in light of a set of PGV observations from a ground motion prediction equation (GMPE). A restricted sampling approach is also developed to incorporate additional physical constraints on the fault plane configuration, and to increase the sampling efficiency.

A subducted oceanic ridge influencing the Nankai megathrust earthquake rupture

2004 ◽  
Vol 217 (1-2) ◽  
pp. 77-84 ◽  
Author(s):  
Jin-Oh Park ◽  
Gregory F Moore ◽  
Tetsuro Tsuru ◽  
Shuichi Kodaira ◽  
Yoshiyuki Kaneda
Keyword(s):  
Earthquake Rupture ◽  
Megathrust Earthquake ◽  
Oceanic Ridge

scholarly journals The influence of depth-varying elastic properties of the upper plate on megathrust earthquake rupture dynamics and tsunamigenesis

2021 ◽  
Author(s):  
Manel Prada ◽  
Percy Galvez ◽  
Jean-Paul Ampuero ◽  
Valenti Sallares ◽  
Carlos Sánchez-Linares ◽  
...  
Keyword(s):  
Elastic Properties ◽  
Earthquake Rupture ◽  
Megathrust Earthquake ◽  
Rupture Dynamics ◽  
Earthquake Rupture Dynamics
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