We describe a large-scale simulation of the seismic wave propagation from the 2011 Tohoku-Oki earthquake. We combine structure models for topography, sediments, crust and subducting plates to construct a 3D structure model for the northeastern Japan area. Then we simulate the near-field wave propagation by using a FDTD method which is accelerated by the use of multi-GPUs (Graphics Processing Un...

We study the ground motion simulations based on three finite-source models for the 2007 Mw6.6 Niigata Chuetsu-oki, Japan, earthquake in order to discuss the performance of the input ground motion estimations for the near-field seismic hazard analysis. The three models include a kinematic source inverted from the regional accelerations, a dynamic source on a planar fault with three asperities in...

[1] Coseismic deformation of the ground can be measured from aerial views taken before and after an earthquake. We chose the area of the Kickapoo-Landers step over along the 1992 Landers earthquake zone, using air photos (scale 1:40,000) scanned at 0.4 m resolution. Two photos acquired after the earthquake are used to assess the accuracy and to evaluate various sources of noise. Optical distort...

[1] The complex geometry of faults, seismicity, and diversity of earthquake mechanisms suggest that the stress and strength in Earth’s crust are spatially heterogeneous. We investigated the degree of heterogeneity using the following two end-member models. In one end-member model, we assumed that the orientation of stress is uniform in the crust as is assumed in many stress inversion studies. I...

[1] The massive tsunami generated by the 11 March 2011 Tohoku earthquake (Mw 9.0) was widely recorded by GPS buoys, wave gauges, and ocean bottom pressure sensors around the source. Numerous inversions for finite‐fault slip time histories have been performed using seismic and/ or geodetic observations, yielding generally consistent patterns of large co‐seismic slip offshore near the hypocenter ...

[1] It’s uncertain whether more near-field earthquakes are triggered by static or dynamic stress changes. This ratio matters because static earthquake interactions are increasingly incorporated into probabilistic forecasts. Recent studies were unable to demonstrate all predictions from the static-stress-change hypothesis, particularly seismicity rate reductions. However, current dynamic stress ...

The near-surface areas of major faults commonly contain weak, phyllosilicate minerals, which, based on laboratory friction measurements, are assumed to creep stably. However, it is now known that shallow faults can experience tens of meters of earthquake slip and also host slow and transient slip events. Laboratory experiments are generally performed at least two orders of magnitude faster than...

The great Sumatra–Andaman earthquake of 26 December 2004 (UTC 00:58:53) was a momentous event, whether measured by scientific or human standards. Sadly, what is currently regarded as the third largest earthquake in recorded history led to the worst tsunami disaster in recorded history, with the loss of more than 200,000 lives and devastation throughout the Bay of Bengal. About three months late...

The on-site earthquake early warning system is under development for the area near the earthquake epicenter to provide information such as earthquake magnitude, the arrival time and the intensity of the strong shaking for free field as well as the structural response, etc. The real-time strong motion signals recorded from Taiwan Strong Motion Instrumentation Program (TSMIP) were used to train n...