Science of Slow Earthquakes

Science of Slow Earthquakes - Toward a unified understanding of all earthquake events from low-speed deformation to high-speed slip

Project OverviewGroup C01: Geoscientific Modeling (Area number: JP16H06477)
Study on Geoscientific Modeling of Earthquake Phenomena from Low-speed Deformation to High-speed SlipLeader: Satoshi IDE, Department of Earth and Planetary Science, The University of Tokyo

  1. Admin, Int
  2. A01
  3. A02
  4. B01
  5. B02
  6. C01
  7. C02

Purpose of the Research Project

Science of Slow Earthquakes aims at clarifying the style, environment and mechanism of slow earthquake occurrence. The role of Research Group C01 is to determine their occurrence mechanism by geoscientific modeling.
Slow earthquakes have several different aspects; tremor, low-frequency earthquakes and slow slips. Many of them are observed along subducting zones with considerable regional differences. Slow earthquakes often occur in the surrounding area of the source region of mega earthquakes, and there must be some relations between slow and mega earthquakes. This research group intend to examine the spatiotemporal relation among various phenomena of slow earthquakes, to construct numerical models assuming realistic conditions and to investigate predictability of the system of plate tectonics including mega earthquakes. A wide range of knowledge attained from numerical calculations, physical theories and experiments will be incorporated into various laws and theories derived/developed by member researchers in their past studies. Utilizing the outcomes of other research groups, geoscientific observations, geological observations/experiments, physical theories/experiments, with appropriate feedbacks to them, we will proceed interdisciplinary researches. We will explain the differences among various phenomena with realistic numerical models referring the differences of geoscientific environment in plate interfaces worldwide.

Figure 1. Realistic slow earthquake model in western Japan

Details of the Research

Researches are to be proceeded focusing on the following three categories.

  • A) Clarification of the Spatiotemporal Relationship among Slow Earthquake Phenomena
    Aiming to find the fundamental law that controls slow earthquakes, we will conduct quantitative researches on the characteristics of tremor, very-low frequency earthquakes and slow slips. In the meantime, we will create numerical models from the estimated value of released energy amount and duration to determine special difference and its causal force.
  • B) Modeling Realistic Tectonic Plate Motion Systems
    We will construct a slow earthquake cycle model in which realistic shape of plate interface and law of friction are incorporated. At the same time, we will incorporate thermal structure, influence of fluid and hierarchical structure in the cycle model. We intend to establish a universal numerical model which explains mechanisms of slow earthquakes and the mega-earthquake occurring process.
  • C) Examination of Predictability of Mega-earthquakes and the Tectonic Plate Movement
    We will conduct surveys on occurrence conditions of slow earthquakes before/after the occurrence of mega-earthquakes by experiments and analyses of seismic waves. We intend to examine predictability of the plate tectonic system. We will also determine the response of the system which may be influenced by changes in external conditions such as tides.

Members

Project Leader
  • IDE SatoshiDepartment of Earth and Planetary Science, The University of Tokyo
Co-investigators
  • MATSUZAWA TakanoriEarthquake and Tsunami Research Division, National Research Institute for Earth Science and Disaster Resilience
  • MITSUI YutaFaculty of Science, Shizuoka University
  • FUKUYAMA EiichiGraduate School of Engineering, Kyoto University
  • ARIYOSHI KeisukeResearch Institute for Marine Geodynamics, Japan Agency for Marine-Earth Science and Technology
  • YOSHIOKA ShoichiResearch Center for Urban Safety and Security, Kobe University
  • NAKANO MasaruResearch and Development Center for Earthquake and Tsunami, Japan Agency for Marine-Earth Science and Technology
  • YAMASHITA FutoshiEarthquake and Tsunami Research Division, National Research Institute for Earth Science and Disaster Resilience
Research Collaborators
  • YAGI YujiGraduate School of Life and Environmental Sciences, University of Tsukuba
  • ANDO RyosukeSchool of Science, The University of Tokyo
  • SHIBAZAKI BunichiroInternational Institute of Seismology and Earthquake Engineering, Building Research Institute
  • HORI TakaneResearch Institute for Marine Geodynamics, Japan Agency for Marine-Earth Science and Technology
  • ASO NaofumiSchool of Science, Tokyo Institute of Technology
  • YABE SuguruGeological Survey of Japan, National Institute of Advanced Industrial Science and Technology
  • ICHIMURA TsuyoshiEarthquake Research Institute, The University of Tokyo
  • NISHIKAWA TomoakiDisaster Prevention Research Institute, Kyoto University
  • AGATA RyoichiroResearch Institute for Marine Geodynamics, Japan Agency for Marine-Earth Science and Technology
  • TOH AkikoSchool of Science, The University of Tokyo
  • MORISHIGE ManabuDepartment of Mathematical Science and Advanced Technology, Japan Agency for Marine-Earth Science and Technology

Group Research Subthemes

Co-investigater's Subjects
  • IDE Satoshi Generalization of Slow Earthquake based on various regional studies
  • MATSUZAWA Takanori Comprehensive numerical model of slow slip events in subduction zones, considering constraint from observations
  • MITSUI Yuta Exploring new factors for slow earthquake occurrences
  • FUKUYAMA Eiichi, YAMASHITA Futoshi Modeling of slow slip events based on large-scale friction experiments
  • ARIYOSHI Keisuke Disturbance Model
  • YOSHIOKA Shoichi Relationship between slow earthquakes in circum-Pacific region and temperature & dehydration through 3-D numerical modeling