scholarly journals Long-period ground motion simulation using centroid moment tensor inversion solutions based on the regional three-dimensional model in the Kanto region, Japan

2020 ◽  
Author(s):  
Shunsuke Takemura ◽  
Kazuo Yoshimoto ◽  
Katsuhiko Shiomi
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Moment Tensor ◽  
Three Dimensional ◽  
Centroid Moment Tensor ◽  
Velocity Models ◽  
Long Period ◽  
Ground Motion Simulations ◽  
Kanto Basin ◽  
Long Period Ground Motion

Abstract We conducted centroid moment tensor (CMT) inversions of moderate ( Mw 4.5–6.5) earthquakes in the Kanto region, Japan, using a local three-dimensional (3D) model. We then investigated the effects of our 3D CMT solutions on long-period ground motion simulations. Grid search CMT inversions were conducted using displacement seismograms for periods of 25–100 s. By comparing our 3D CMT solutions with those from the local one-dimensional (1D) catalog, we found that our 3D CMT inversion systematically provides magnitudes smaller than those in the 1D catalog. The Mw differences between 3D and 1D catalogs tend to be significant for earthquakes within the oceanic slab. By comparing ground motion simulations between 1D and 3D velocity models, we confirmed that observed Mw differences could be explained by differences in the rigidity structures around the source regions between 3D and 1D velocity models. The 3D velocity structures (especially oceanic crust and mantle) are important for estimating seismic moments in intraslab earthquakes, which are related to fault size estimation. A detailed discussion for intraslabe seismicity can be conducted by using the 3D CMT catalog. The seismic moments also directly affect the amplitudes of ground motions. The 3D CMT catalog allows us to directly conduct the precise forward and inverse modeling of long-period ground motion without adjusting source models, which have been typically applied in the cases using the 1D CMT catalog. We also conducted long-period ground motion simulations using our 3D CMT solutions to evaluate the reproducibility of long-period ground motions at stations within the Kanto Basin. The simulations of our 3D CMT solutions well-reproduced observed ground motions for periods longer than 10 s, even at stations within the Kanto Basin. The reproducibility of simulations was improved from those using solutions in the 1D catalog.

scholarly journals Long-Period Ground Motion Simulation Based on Three-dimensional Centroid Moment Tensor Inversion Solutions in the Kanto Region, Japan

2020 ◽  
Author(s):  
Shunsuke Takemura ◽  
Kazuo Yoshimoto ◽  
Katsuhiko Shiomi
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Moment Tensor ◽  
Three Dimensional ◽  
Centroid Moment Tensor ◽  
Velocity Models ◽  
Long Period ◽  
Ground Motion Simulations ◽  
Kanto Basin ◽  
Long Period Ground Motion

Abstract We conducted centroid moment tensor (CMT) inversions of moderate (Mw 4.5–6.5) earthquakes in the Kanto region, Japan, using a local three-dimensional (3D) model. We then investigated the effects of our 3D CMT solutions on long-period ground motion simulations. Grid search CMT inversions were conducted using displacement seismograms for periods of 25–100 s. By comparing our 3D CMT solutions with those from the local one-dimensional (1D) catalog, we found that our 3D CMT inversion systematically provides magnitudes smaller than those in the 1D catalog. The Mw differences between 3D and 1D catalogs tend to be significant for earthquakes within the oceanic slab. By comparing ground motion simulations between 1D and 3D velocity models, we confirmed that observed Mw differences could be explained by differences in the rigidity structures around the source regions between 3D and 1D velocity models. The 3D velocity structures (especially oceanic crust and mantle) are important for estimating seismic moments in intraslab earthquakes. The seismic moments directly affect the amplitudes of ground motions. Thus, 3D CMT solutions are essential for the precise forward and inverse modeling of long-period ground motion. We also conducted long-period ground motion simulations using our 3D CMT solutions to evaluate reproducibility of long-period ground motions at stations within the Kanto Basin. The simulations of our 3D CMT inversion well-reproduced observed ground motions for periods longer than 10 s, even at stations within the Kanto Basin.

scholarly journals Long-period ground motion simulation using centroid moment tensor inversion solutions based on the regional three-dimensional model in the Kanto region, Japan

2020 ◽  
Author(s):  
Shunsuke Takemura ◽  
Kazuo Yoshimoto ◽  
Katsuhiko Shiomi
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Moment Tensor ◽  
Three Dimensional ◽  
Centroid Moment Tensor ◽  
Velocity Models ◽  
Long Period ◽  
Ground Motion Simulations ◽  
Kanto Basin ◽  
Long Period Ground Motion

Abstract We conducted centroid moment tensor (CMT) inversions of moderate (Mw 4.5–6.5) earthquakes in the Kanto region, Japan, using a local three-dimensional (3D) model. We then investigated the effects of our 3D CMT solutions on long-period ground motion simulations. Grid search CMT inversions were conducted using displacement seismograms for periods of 25–100 s. By comparing our 3D CMT solutions with those from the local one-dimensional (1D) catalog, we found that our 3D CMT inversion systematically provides magnitudes smaller than those in the 1D catalog. The Mw differences between 3D and 1D catalogs tend to be significant for earthquakes within the oceanic slab. By comparing ground motion simulations between 1D and 3D velocity models, we confirmed that observed Mw differences could be explained by differences in the rigidity structures around the source regions between 3D and 1D velocity models. The 3D velocity structures (especially oceanic crust and mantle) are important for estimating seismic moments in intraslab earthquakes, which are related to fault size estimation. A detailed discussion for intraslabe seismicity can be conducted by using the 3D CMT catalog. The seismic moments also directly affect the amplitudes of ground motions. The 3D CMT catalog allows us to directly conduct the precise forward and inverse modeling of long-period ground motion without adjusting source models, which have been typically applied in the cases using the 1D CMT catalog. We also conducted long-period ground motion simulations using our 3D CMT solutions to evaluate the reproducibility of long-period ground motions at stations within the Kanto Basin. The simulations of our 3D CMT solutions well-reproduced observed ground motions for periods longer than 10 s, even at stations within the Kanto Basin. The reproducibility of simulations was improved from those using solutions in the 1D catalog.

scholarly journals Long-period ground motion simulation using centroid moment tensor inversion solutions based on the regional three-dimensional model in the Kanto region, Japan

2020 ◽  
Author(s):  
Shunsuke Takemura ◽  
Kazuo Yoshimoto ◽  
Katsuhiko Shiomi
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Moment Tensor ◽  
Three Dimensional ◽  
Centroid Moment Tensor ◽  
Long Period ◽  
Ground Motion Simulations ◽  
Kanto Basin ◽  
Long Period Ground Motion ◽  
Kanto Region

Abstract We conducted centroid moment tensor (CMT) inversions of moderate (Mw 4.5–6.5) earthquakes in the Kanto region, Japan, using a local three-dimensional (3D) model. We then investigated the effects of our 3D CMT solutions on long-period ground motion simulations. Grid search CMT inversions were conducted using displacement seismograms for the periods of 25–100 s. By comparing our 3D CMT solutions with those from the local one-dimensional (1D) catalog, we found that our 3D CMT inversion systematically provides magnitudes smaller than those in the 1D catalog. The Mw differences between 3D and 1D catalogs tend to be significant for earthquakes within the oceanic slab. By comparing the ground motion simulations of the 1D and 3D velocity models, we confirmed that the observed Mw differences could be explained by the differences in the rigidity structures around the source regions in the two models. The 3D velocity structures (especially oceanic crust and mantle) are important for estimating seismic moments in intraslab earthquakes. The seismic moments directly affect the amplitudes of ground motions. Thus, 3D CMT solutions are essential for precise forward and inverse modeling of long-period ground motion. We also conducted long-period ground motion simulations using our 3D CMT solutions to evaluate the reproducibility of long-period ground motions at stations within the Kanto Basin. The simulations of our 3D CMT solutions well-reproduced observed ground motions for periods longer than 10 s, even at stations within the Kanto Basin. The reproducibility of simulations using our 3D CMT solutions was better than those based on the solutions in the 1D catalog.

Three-dimensional finite-difference simulations of long-period strong motions in the Tokyo metropolitan area during the 1990 Odawara earthquake (MJ 5.1) and the great 1923 Kanto earthquake (MS 8.2) in Japan

1999 ◽  
Vol 89 (3) ◽  
pp. 579-607 ◽  
Author(s):  
Toshiaki Sato ◽  
Robert W. Graves ◽  
Paul G. Somerville
Keyword(s):  
Finite Difference ◽  
Ground Motions ◽  
Three Dimensional ◽  
Velocity Model ◽  
Tokyo Metropolitan Area ◽  
Long Period ◽  
Kanto Earthquake ◽  
3D Velocity Model ◽  
Kanto Basin ◽  
Dominant Period

Abstract Utilizing a crustal velocity model that includes the complexity of the irregular subsurface structure of the Kanto basin, we have performed three-dimensional (3D) finite-difference (FD) simulations of near-source long-period strong ground motions in the Tokyo metropolitan area for the 1990 Odawara (MJ 5.1) and the 1923 Kanto (MS 8.2) earthquakes. Constraints on the development of the 3D velocity model come from available geological and geophysical data, as well as our previous 1D waveform modeling results (Sato et al., 1998a). The simulation of the moderate-sized Odawara earthquake demonstrates that the 3D velocity model works quite well at reproducing the recorded long-period (T > 3.33 sec) strong motions, including basin-generated surface waves, for a number of sites located throughout the Kanto basin region. Using this validated 3D model along with the variable-slip rupture model of Wald and Somerville (1995), we then simulate the long-period (T > 4 sec) ground motions in this region for the 1923 Kanto earthquake. The simulation results for the 1923 event show that the largest ground motions occur east of the epicenter along the central and southern part of the Boso Peninsula. These large motions arise from strong rupture directivity effects and are comprised of relatively simple, source-controlled pulses with a dominant period of about 10 sec. North of the epicentral region, in the Tokyo area, 3D basin-generated phases are quite significant, and these phases produce large-amplitude late-arriving pulses in the ground motions. At station Hongo (HNG), which is the only site having digitized and restored near-fault strong-motion records for this event, our 3D simulations compare quite well with the ground motions of the restored Imamura seismogram. For the restored Ewing record, our 3D simulations reproduce the phase and amplitude of the initial pulses of motion; however, the dominant period of the large-amplitude later phases is noticeably shorter in the simulations (about 5 to 6 sec) than in the observation (13 sec). These results suggest that the restored Imamura seismogram may be a better representation of the gross features of the actual motion than the restored Ewing seismogram, although the first (clipped and restored) part of the Imamura seismogram may still underestimate the strength of the actual motion.

Study on Long-Period Inelastic Spectra of near-Fault Pulse-Like Strong Ground Modeled Using Analytical Model

2011 ◽  
Vol 374-377 ◽  
pp. 2316-2319
Author(s):  
Chun Feng Li ◽  
Wei Xin Tian ◽  
Zhuo Lin
Keyword(s):  
Ground Motion ◽  
Analytical Model ◽  
Ground Motions ◽  
Near Field ◽  
Near Fault ◽  
Long Period ◽  
Acceleration Time Histories ◽  
Long Period Ground Motion ◽  
Ground Motion Records ◽  
Strong Ground

Because the parameters of Mavroeidis analytical model of pulse-like strong ground motion have an unambiguous physical meaning, the analytical model has been calibrated using a large number of actual near-field ground-motion records, and It can successfully simulate available near-fault pulse-like acceleration time histories, in this paper, we synthesize ground motions using the model to investigate elasto-plastic earthquake responses of long period single-degree-of-freedom system to the pulse-like ground motions, revealing the elasto-plastic long-period ground motion characteristics of pulse-like ground motion.

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