Name: KATO, Aitaro
Position:Associate Professor
Division/Center: Earthquake Prediction Research Center
Research Area: Earthquake source physics, Seismic observation
URL: http://www.eri.u-tokyo.ac.jp/people/akato/

Last Update 09/01 2016

Research:

I am very interested with a nucleation process of megathrust along plate interface. Based on a spatial temporal evolution of seismicity prior to major earthquakes (foreshock) including repeating earthquakes, which has been interpreted as creep meter on plate interface, I have recently revealed gradual unlocking of some portions hosting large earthquakes. In addition, I am working about a long-term behavior of low-frequency earthquakes located at down-dip extension of megathrust along Nankai Trough. These low-frequency earthquakes occur at a transition between fully locked and creeping portions on plate interface, so provide us important information about locking status therein. I have also great interest in driving mechanisms of immediate aftershocks as well as intensive seismic swarms, through seismicity analysis, revealing heterogeneities of stress field and seismic structures in the source regions.

Publications:

Kodaira, S., T. Iidaka, A. Kato, J. O. Park, T. Iwasaki and Y. Kaneda, Structural evidences for a cause of silent slip in the rupture zone of the great Tokai earthquake, central Japan, Science, 304, 1295--1298, 2004.

Kato, A., E. Kurashimo, N. Hirata, S. Sakai, T. Iwasaki and T. Kanazawa, Imaging the source region of the 2004 mid-Niigata prefecture earthquake and the evolution of a seismogenic thrust-related fold,, Geophys. Res. Lett., 32, L07307, doi:10.1029/2005GL022366, , 2005.

Kato, A., S. Sakai, N. Hirata, E. Kurashimo, T. Iidaka, T. Iwasaki, and T. Kanazawa, Imaging the seismic structureand stress field in the source region of the 2004 mid-Niigata prefecture earthquake: Structural zones of weakness and seismogenicstress concentration by ductile flow, J. Geophys. Res. 111, B08308, doi:10.1029/2005JB004016., , 2006.

Kato, A., T. Iidaka, E. Kurashimo, S. Nakagawa, N. Hirata, and T. Iwasaki, Delineation of probable asperities on the Atotsugawa fault, centralJapan, using a dense temporary seismic network, Geophys. Res. Lett., 34, L09318, doi:10.1029/2007GL029604., , 2007.

Kato, A., E. Kurashimo, T. Igarashi, S. Sakai, T. Iidaka, M. Shinohara, T. Kanazawa, T. Yamada, N. Hirata, and T. Iwasaki, Reactivation of ancient rift systems triggers devastating intraplate earthquakes, Geophys. Res. Lett., 36, L05301, doi:10.1029/2008GL036450., , 2009.

Kato, A., T. Iidaka, R. Ikuta, Y. Yoshida, K. Katsumata, T. Iwasaki, S. Sakai, C. Thurber, N. Tsumura, K. Yamaoka, T. Watanabe, T. Kunitomo, F. Yamazaki, M. Okubo, S. Suzuki, N. Hirata , Variations of fluid pressure within the subducting oceanic crust and slow earthquakes, Geophys. Res. Lett., 37, L14310, doi:10.1029/2010GL043723, , 2010.

Kato, A., K. Obara, T. Igarashi, H. Tsuruoka, S. Nakagawa and N. Hirata, Propagation of Slow Slip Leading Up to the 2011Mw 9.0 Tohoku-Oki Earthquake, Science, 335, 6069, 705, doi:10.1126/science.1215141--708, 2012.

Kato, A., and T. Igarashi, Regional extent of the large coseismic slip zone of the 2011 Mw 9.0 Tohoku-Oki earthquake delineated by on-fault aftershocks, Geophys. Res. Lett., 39, L15301, doi:10.1029/2012GL052220, , 2012.

Kato, A., T. Igarashi, K. Obara, S. Sakai, T. Takeda, A. Saiga, T. Iidaka, T. Iwasaki, N. Hirata, K. Goto, H. Miyamachi, T. Matsushima, A. Kubo, H. Katao, Y. Yamanaka, T. Terakawa, H. Nakamichi, T. Okuda, S. Horikawa, N. Tsumura, N. Umino, T. Okada, M. Kosuga, H. Takahashi and T. Yamada, Imaging the source regions of normal faulting sequences induced by the 2011 M9.0 Tohoku-Oki earthquake, Geophys. Res. Lett., 40, doi:10.1002/grl.50104, , 2013.

Kato, A., J. Fukuda, and K. Obara, Response of seismicity to static and dynamic stress changes induced by the 2011 M9.0 Tohoku-Oki earthquake, Geophys. Res. Lett., 40, doi:10.1002/grl.50699, , 2013.

Kato, A., and S. Nakagawa, Multiple slow-slip events during a foreshock sequence of the 2014 Iquique, Chile Mw 8.1 earthquake, Geophys. Res. Lett., 41, doi:10.1002/2014GL061138, , 2014.

Kato, A., T. Terakawa, Y. Yamanaka, Y. Maeda, S. Horikawa, K. Matsuhiro and T. Okuda, Preparatory and precursory processes leading up to the 2014 phreatic eruption of Mount Ontake, Japan, Earth Planets Space, 67, 111, doi:10.1186/s40623-015-0288-x, , 2015.

Kato, A., J. Fukuda, T. Kumazawa and S. Nakagawa, Accelerated nucleation of the 2014 Iquique, Chile Mw 8.2 Earthquake, Scientific Reports, 6, 24792, doi: 10.1038/srep24792, , 2016.

Kato, A., J. Fukuda, S. Nakagawa and K. Obara, Foreshock migration preceding the 2016 Mw 7.0 Kumamoto earthquake, Japan, Geophys. Res. Lett., doi: 10.1002/2016GL070079, , 2016.