Seismotectonics Research Group
Our group aims to elucidate the physical and mechanical properties of seismogenic zone and the generation processes of large earthquakes by linking field surveys of fault rocks, laboratory experiments, numerical simulations, seismological observations and data analysis. We are currently making a seismotectonic map in Kanto region based on detailed local stress fields, studying the deformation process of fault rocks from brittle to ductile region, and developing the computer simulation technique of earthquake cycles by integrating paleoearthquake information and geophysical data. These studies provide a basis for improving accuracies of long-term earthquake forecasting and evaluating the size of earthquake.
Research approach of our group to elucidate the physical and mechanical properties of seismogenic zone and the generation processes of large earthquakes.
Member
- Miki Takahashi (Leader, Group)
- Haruo Horikawa (Senior Researcher)
- Norio Shigematsu (Senior Researcher)
- Takahiko Uchide (Chief Senior Researcher)
- Yumi Urata (Senior Researcher)
- Takahiro Shiina (Senior Researcher)
- Kodai Sagae (AIST Postdoctoral Researcher)
- Yasunori Sawaki (AIST Postdoctoral Researcher)
- Yeo Thomas (Research Assistant)
- Reiken Matsushita (Technical Staff)
- Misato Nakai (Technical Staff)
In order to understand earthquake generation mechanisms, I am measuring the deformation and physical properties of rocks under the high-temperatures and high-pressures in the laboratory. My research interests focus on the frictional behaviors of materials in brittle-plastic transition regions and effects of pore fluid pressure on the frictional behaviors.
I study intraplate earthquakes and related matters, in particular, fault geometry beneath active faults (in the seismogenic layer) and basement structure beneath the sedimentary basins from seismic reflection profiling and source models of historical earthquakes that presumably occurred as intraplate event but do not have records with modern instruments.
I am studying on inland-earthquake generation processes based on the investigation of geological survey of exhumed past hypocentral regions. I will use this information to investigate the processes of deformation of rocks in the laboratory at high pressures and high temperatures to improve accuracy of forecasting a large earthquake occurrence.
I am interested in earthquake source processes from various points of view, such as the scaling of earthquake rupture growth and frequency-dependent seismic radiation from an earthquake source. I am an expert at seismological data analysis.
I am currently working on, in addition to the above, source properties of small and moderate earthquakes, which may give us a clue to understand past and future large earthquakes on the same active fault.
I am interested in the physical mechanism of large earthquakes. I work on numerical modeling and simulations using data of a rock friction experiment and of seismological and geodetic observation.
I am investigating internal structures of the Earth based on analyses of seismic waveforms observed for natural earthquakes. By utilizing various types of seismic waves, I try to retrieve fine-scale heterogeneous structures in seismogenic zones and improve understandings for the physical and material conditions that relate to genesis of earthquakes.
I have determined source locations of tectonic tremors and developed a method for automatically extracting spatio-temporal evolutions of their sources. I aim to elucidate the physical mechanism of the slow earthquake by investigating the growth processes of slow earthquake phenomena (e.g. tectonic tremor) in detail.
Seismograms from teleseismic, regional or local earthquakes contain numerous information regarding to heterogenous structures of the interior Earth. I have investigated seismic impedance contrasts and its relationship with slow earthquake activities around the Nankai subduction zone. I am currently studying the heterogenous structure around local faults and inland seismicity and try to understand the spatial and temporal features of the seismicity and fluid condition.
The main purpose of my research is to understand the inland earthquake generation processes from a geological viewpoint. This involve characterising fault rocks that represent the deformation that occurred from the brittle-ductile transition zone to the seismogenic region which are thougght to be the exhumed hypocentre of earthquake. My study will mainly focus on describing the heterogeneity of the deformational structures observed within the MTL fault zone in order to enhance our understanding in the interplay of deformational mechanism that took place and their relationship with any seismic events.
I am studying automated seismic data processing techniques to improve the accuracy of seismic phase picking and hypocenter determination. So far, I have learned how to manually pick seismic phases, determine hypocenters and magnitudes of earthquakes, unify the data formats of different datasets, etc. On the basis of these experiences, I aim to develop a sophisticated system for automated seismic data processing incorporating various state-of-the-art techniques and hope to contribute towards the elucidation of large earthquake generation mechanism.
I have been working on database managements, scripting and map drawings by various GIS softwares, and engaged in research assistances and building systems for research results with those skills.