Macroscopic methods (FEM, FD, PS, SE) of earthquake faulting and waves
Convenors: K. Hirahara (Japan), D. Komatitsch (USA)
Session Overview: Kazuro Hirahara, Nagoya University (15 minutes)
Numerical simulation of earthquake faulting and wave propagation in realistic media, that include laterally heterogeneous elastic and viscoelastic complexity with several scales, requires highly sophisticated numerical techniques. The objective of this session 3.1 is to study computational methods and algorithms for the simulation models, common tools and routines for their implementation on super-parallel computer systems for large-scale problems, discussion of efficient methods for mesh design in 3D for real structures, and visualization and evaluation strategy of simulation results. We examine the present status in this subject and discuss future directions. In this session, we would like to explore the following three issues:
1. Towards large-scale computing:
For large-scale problems with typically 100 million degrees of freedom or more, special simulation techniques are required, especially when using parallel computers. These new techniques are discussed and analyzed.
2. Towards more realistic simulation of earthquake cycle and earthquake faulting:
We discuss technical problems related to the quasi-static simulation of earthquake cycle on plate interfaces and inland faults due to relative plate motions, which are in particular the introduction and correct representation of the fault interface, the allowance of a large amount of slip on the interface, the implementation of friction laws, anelastic properties, and so on. Problems related to dynamic simulation of earthquake faulting are also examined.
3. Towards realistic simulation of wave propagation in large-scale complex media:
As observed for instance during the 1995 Kobe earthquake, abnormally strong ground motion, which is caused by the interaction of complex surface structure and waves emitted from the propagating rupture of earthquake faulting, causes great disaster. We discuss technical problems related to realistic simulation of wave propagation in such basin structures, as well as in faulting regions.
Session Plenary: (1 Hour)
Genki Yagawa, Hiroshi Okuda, and Hisashi Nakamura (30 minutes, including. 10 minutes discussion) Development of High-Performance Parallel Finite Element System for Solid Earth -GeoFEM Project Jacobo Bielak and Omar Ghattas (30 minutes, including 10 minutes for discussion) Computational Challenges in Seismology
Detailed Session: (2.5 Hours)
1. Towards large-scale computing Kazuteru Garatani (15 minutes) Feasibility Study of GeoFEM for Solving 100 Million DOF Problems Kengo Nakajima (15 minutes) Convergence Acceleration Method of Large-Scale Parallel Iterative Solvers for Heterogeneous Properties Comments and discussions (20 minutes) 2. Towards more realistic simulation of earthquake cycle and earthquake faulting Kazuro Hirahara (15 minutes) Quasi-static simulation of seismic cycle of great inter-plate earthquakes following a friction law in laterally heterogeneous viscoelastic medium under gravitation - FEM Approach Z. Guo, A. Makinouchi, and T.Fujimoto (15 minutes) FEM Simulation of Dynamic Sliding of Faults Connecting Static Deformation Process to Dynamic Process Mikio Iizuka (15 minutes) Nonlinear Structural Subsystem of GeoFEM for Fault Zone Analysis Comments and discussions (20 minutes) 3. Towards realistic simulation of wave propagation in large-scale complex media Dimitri Komatitsch, Christophe Barnes, and Jeroen Tromp (15 minutes) A spectral element method for wave propagation simulation applied to 3D basins, and to a fluid-solid interface Comments and discussions (20 minutes)