Risk Evaluation and Disaster Mitigation Research Division
Inland Earthquake and Volcano Lab
Associate Professor
Ph.D. (Volcanology)

Concurrent: Graduate School of Science
Research Subject(s)
I mainly explore the physics of earthquake generation using geodetic data, focusing on surface deformation detection using satellite SAR data (InSAR) and on fault mechanics through data modeling. Recently, I am also interested in how uncertain scientific knowledge could be effectively used in the society.
Key Words
Crustal deformation / Geodesy / Earthquake / Volcano / Modeling
Research Activities

[Understanding earthquake occurrence mechanisms and seismotectonics through InSAR and modeling]
A number of studies were done on estimating earthquake fault slip models using InSAR (and GNSS, if available) data. These studies (and many other studies performed by researchers worldwide) found that heterogeneous slip distributions, rough surface ruptures, and branching of slips are quite general. These findings obtained from the high-quality InSAR data that complexity of earthquake rupture is an ubiquitous feature.

[Detection of fault creep]
By applying InSAR time-series analysis using many SAR images, we can detect small ground displacements of a few mm/year. In the study of the Philippine Fault, our study revealed that the fault creep stressed a locked portion along the fault and eventually led to occurrence of an Mw6.5 earthquake.

[Modeling volcanic deformation using InSAR]
For my Ph.D. thesis, I worked on the deformation associated with eruptions at Piton de la Fournaise volcano in the Reunion Island. The satellite interferometry (InSAR) data clearly captured the deformation due to dike intrusions. Another work has shown that the 2011 Mw9.0 Tohoku-oki earthquake triggered subsidence around five active volcanoes, which could be associated with weak materials in volcanic regions.

Selected Works

Fukushima, Y., M. Hashimoto, M. Miyazawa, N. Uchida, and T. Taira (2019), Surface creep rate distribution along the Philippine fault, Leyte Island, and possible repeating of Mw∼6.5 earthquakes on an isolated locked patch, Earth Planets and Space, 71, 118, doi:10.1186/s40623-019-1096-5.

Fukushima, Y., S. Toda, S. Miura, D. Ishimura, J. Fukuda, T. Demachi, and K. Tachibana (2018), Extremely early recurrence of intraplate fault rupture following the Tohoku-Oki earthquake, Nature Geoscience, 11, 777–781, doi:10.1038/s41561-018-0201-x.

Conway, S., C. Wauthier, Y. Fukushima, and M. Poland (2018), A retrospective look at the February 1993 east rift zone intrusion at Kilauea volcano, Hawaii, J. Volcanol. Geotherm. Res., doi:10.1016/j.jvolgeores.2018.05.017.

Takada, Y., and Y. Fukushima (2013), Volcanic subsidence triggered by the 2011 Tohoku earthquake in Japan, Nature Geoscience, 6, 637-641, doi: 10.1038/NGEO1857.

Fukushima, Y., Y. Takada, and M. Hashimoto (2013), Complex ruptures of the 11 April 2011 Iwaki earthquake (Mw 6.6) triggered by the 11 March 2011 Tohoku earthquake (Mw 9.0), Japan, Bull. Seismol. Soc. Am., 103, 1572–1583, doi:10.1785/0120120140.

Selected Memberships
  • Geodetic Society of Japan
  • Seismological Society of Japan
  • Japan Geosciences Union
  • American Geophysical Union
  • European Geosciences Union
Selected Awards
  • Prominent student presentation award, Geodetic Society of Japan (2004)
  • Research award, Volcanological Society of Japan (2011)