日時：2024年 6月 24日 (月) 16:00 - [ Date & Time: June 24th, 16:00- ]
場所：防災研究所 地震災害研究センター セミナー室 200 [Place: C200 in EQHZ building, DPRI]
Title：Modeling the Episodic Behavior and Along-Fault Variability of Slow Earthquakes through Viscoelastic and Damage Rheology
Speaker：Dr. Sina Massoumi
Postdoc researcher, Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes, Grenoble, France
Abstract：
Slow earthquakes, characterized by episodic slips and correlated tectonic tremors, are primarily identified at transitional zones between locked and stable slip regions. Their characteristics, such as slip/tremor magnitude and recurrence interval, vary along the fault line and are influenced by changes in fault-zone rheology associated with depth-dependent thermo-mechanical conditions and rock composition. This study investigates the episodic behavior and along-fault variability of slow earthquakes using finite element numerical modeling, employing a novel approach that integrates Maxwell viscoelasticity and damage rheology. Unlike conventional rate-and-state modeling, which assumes negligible fault thickness with frictional laws, our method incorporates finite fault thickness that varies over time through a damage mechanism and healing effects, allowing the prediction of both displacements and seismic tremors.
Using a continuum volumetric rheology approach, this study explores the effects of along-fault variations in mechanical parameters such as viscosity, shear strength, and healing on slow slip and tremors. Furthermore, it demonstrates that pore-pressure variations significantly impact the damage mechanism and healing processes. The research provides insights into the spatial and temporal changes in displacement and tremor activities during slow earthquakes. The model successfully replicates observed recurrence times, displacement gradients, and synchronous occurrences of slow slip and tremors. Additionally, it can predict the concentration of tremor energy observed at specific depths in the Cascadia and Mexican subduction zones, underscoring its efficacy in capturing real-world dynamics.
日時：2024年 6月 24日 (月) 16:00 - [ Date & Time: June 24th, 16:00- ]
場所：防災研究所 地震災害研究センター セミナー室 200 [Place: C200 in EQHZ building, DPRI]
Title：Modeling the Episodic Behavior and Along-Fault Variability of Slow Earthquakes through Viscoelastic and Damage Rheology
Speaker：Dr. Sina Massoumi
Postdoc researcher, Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes, Grenoble, France
Abstract：
Slow earthquakes, characterized by episodic slips and correlated tectonic tremors, are primarily identified at transitional zones between locked and stable slip regions. Their characteristics, such as slip/tremor magnitude and recurrence interval, vary along the fault line and are influenced by changes in fault-zone rheology associated with depth-dependent thermo-mechanical conditions and rock composition. This study investigates the episodic behavior and along-fault variability of slow earthquakes using finite element numerical modeling, employing a novel approach that integrates Maxwell viscoelasticity and damage rheology. Unlike conventional rate-and-state modeling, which assumes negligible fault thickness with frictional laws, our method incorporates finite fault thickness that varies over time through a damage mechanism and healing effects, allowing the prediction of both displacements and seismic tremors.
Using a continuum volumetric rheology approach, this study explores the effects of along-fault variations in mechanical parameters such as viscosity, shear strength, and healing on slow slip and tremors. Furthermore, it demonstrates that pore-pressure variations significantly impact the damage mechanism and healing processes. The research provides insights into the spatial and temporal changes in displacement and tremor activities during slow earthquakes. The model successfully replicates observed recurrence times, displacement gradients, and synchronous occurrences of slow slip and tremors. Additionally, it can predict the concentration of tremor energy observed at specific depths in the Cascadia and Mexican subduction zones, underscoring its efficacy in capturing real-world dynamics.
© Research Center for Earthquake Hazards.
© Research Center for Earthquake Hazards.
