Risk Evaluation and Disaster Mitigation Research Division
Subduction Earthquake Lab
Research Subject(s)
Research on huge interplate earthquake based on seafloor geodesy.
Introduction of seafloor geodetic observation abroad and disaster reduction there.
Development of underwater acoustic ranging technique.
Key Words
Solid earth geophysics / Huge interplate earthquake / Seafloor geodesy / Underwater acoustic positioning
Research Activities

Surveying seafloor crustal deformation in and around the earthquake source region in terms of GNSS-acoustic technique to reveal generation mechanism of huge interplate earthquakes. The technique consists of acoustic transponders installed on seafloor as substitute of onshore GNSS antennas, and measure their positions using acoustic ranging from sea surface. Iterated surveys have detected coseismic displacement of 2011 Tohoku earthquake and subsequent postseismic movement as well, which revealed whole process of huge earthquake.

Seafloor geodetic survey is an aggregation highly developed techniques. To spread the same technique and monitor seismic risk in countries of high-risk in earthquake, collaborative researches are conducted overseas.

Autonomous survey is a key technology for the next generation observation of high-frequent and low-cost measurements at increasing number of sites, which can reveal time-dependent phenomena of inter-seismic period. We customize a GNSS-acoustic system that suits for autonomous and long-term measurement on a sea surface platform, called Wave Glider.

Selected Works

Kido, M. et al., (2018) Onboard realtime processing of GPSacoustic data for moored buoy-based observation, Journal of  Disaster Research, 13(3), 472-288,  doi:10.20965/jdr.2018.p0472

Kido, M. et al., (2015) Progress in the Project for Development of GPS/Acoustic Technique Over the Last 4 Years, IAG Symposia, vol.145, doi:10.1007/1345_2015_127

Kido, M. et al., (2011) Trench-normal variation in observed seafloor displacements associated with the 2011 Tohoku-Oki earthquake, Geophysical  Research Letters, 38:L24303. doi:10.1029/2011GL050057

Selected Memberships
  • The Seismological Society of Japan
  • The Geodetic Society of Japan
  • Japan Geoscience Union
  • American Geophysical Union