SCEC Award Number 13190 View PDF
Proposal Category Collaborative Proposal (Integration and Theory)
Proposal Title Simulation and Validation of Long-Period Earthquake Ground Motion in the Kanto Basin in Japan
Investigator(s)
Name Organization
Jacobo Bielak Carnegie Mellon University Ricardo Taborda
Other Participants
SCEC Priorities 6 SCEC Groups GMSV
Report Due Date 03/15/2014 Date Report Submitted N/A
Project Abstract
 This report presents simulations of the 2004 Chuetsu earthquake performed with two available seismic velocity models of Japan for a maximum frequency of 1 Hz and minimum S-wave velocity of 500 m/s. This project is part of the VISES program, and has been conducted with the participation of Professor Tsuyoshi Ichimura of the Earthquake Research Institute of the University of Tokyo. Employing a kinematic source model from an independent inversion study and material models that are developed by National Research Institute for Earth Science and Disaster Prevention (NIED) and Japan Seismic Hazard Information Station (JSHIS), we carried out the simulations using a highly efficient finite element simulator developed to model anelastic wave propagation in large-scale heterogeneous media. Qualitative and quantitative comparisons of the synthetics with the real seismic network data and the analysis of vibration characteristics of the Kanto basin form the two major components of the research presented here. Our validation studies indicate that overall, JSHIS model performs better than NIED model which changes locally in the Kanto basin where NIED model outperforms JSHIS model. Additionally, we demonstrate the wave propagation patterns within the Kanto basin with efficient waveguides in and around it on a graphical basis and elucidate the vibration characteristics of it employing H/V spectral ratio method.
Intellectual Merit Improvement in the understanding of the substructure geological features is critical to study the vibration characteristics of sedimentary basins and access the impacts of possible future earthquakes. Large-scale deterministic numerical simulations of past earthquakes are quite critical to serve to this purpose. The conducted research demonstrates the weak and strong points of two publicly available seismic velocity models of Japan within the context of the 2004 Chuetsu earthquake simulations. Additionally, analysis of the ground motion in the Kanto basin elucidates the characteristics and the variation of the vibration in this region where more than 35 million people reside.
Broader Impacts Knowledge of the ground motion that a structure might experience during its lifetime is the first, critical, step toward the design or retrofit of the structures to withstand future earthquakes. Results of this project provide insight into the spatial distribution of ground motion and how this ground motion can affect the behavior of long-period structures, such as tall buildings and bridges. As part of this project we also examined the coupling of the ground motion in the solid Earth with the ocean water. Results from such analyses will be useful for studying the inception of tsunamis, applications to early warning systems and for estimating the height of the tsunami waves as they get close to the shore. Such information can then be used as the input for studying the run-up and flooding in coastal regions.
Exemplary Figure Figure 5 ( Presented as exemplary figure in the report)