Name: KATO, Aitaro
Division/Center: Earthquake Prediction Research Center
Research Area: Earthquake source physics & Seismic observation

Last Update 09/09 2020


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.


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.

Obara, K. and A. Kato, Connecting slow earthquakes to huge earthquakes, Science, 353 (6296), 253-257. doi:10.1126/science.aaf1512, , 2016.

Toya, M., A. Kato, T. Maeda, K. Obara, T. Takeda and K. Yamaoka, Down-dip variations in a subducting low-velocity zone linked to episodic tremor and slip: a new constraint from ScSp waves, Scientific Reports, 7, 2868, doi:10.1038/s41598-017-03048-6, , 2017.

Kato, A. and T. Ueda, Source fault model of the 2018 Mw 5.6 northern Osaka earthquake, Japan, inferred from the aftershock sequence, Earth Planets Space, 77, 11, doi.10.1186/s40623-019-0995-9, , 2019.

Kano, M., A. Kato and K. Obara, Episodic tremor and slip silently invades strongly locked megathrust zone at the Nankai Trough subduction, Scientific Reports, 9, 9270, doi:10.1038/s41598-019-45781-0, , 2019.

Aitaro Kato and Shigeki Nakagawa, Detection of deep low-frequency earthquakes in the Nankai subduction zone over 11 years using a matched filter technique, Earth Planets Space,, , 2020.

Aitaro Kato and Yehuda Ben-Zion, Generation of Large Earthquakes, Nature Reviews Earth & Environment, in press, , 2020.

加藤愛太郎, スラブ由来の地殻流体と地震発生, 2011年度日本地球化学会年会, 北海道大学,札幌, 9月14‐16日, 招待講演, , 2011.

Aitaro Kato, and Kazushige Obara, A variety and interplay of slip behaviors along plate interface before and after the 2011 Mw9.0 Tohoku-Oki earthquake, AGU, San Francisco, California, USA, Dec. 9-13, Invited talk, , 2013.

Kato, A., and K. Obara, Step-like migration of early aftershocks following the 2007 Mw 6.7 Noto-Hanto earthquake, Japan, the 2014 AGU Fall Meeting, AGU, San Francisco in USA, 12月19日, Invited talk, , 2014.

Kato, A., Overview of the 2011 Tohoku Earthquake & Slow Slip and Large Earthquakes, Advanced School on Megathrust Earthquakes and Tsunami the Abdus Salam International Centre for Theoretical Physics, Trieste in Italy, 10月25日, Invited lecturer, , 2015.

Kato, A., Partial Unlocking of Faults by Mixed Aseismic and Seismic Slip Processes prior to Earthquake, AGU, San Francisco, California, USA, 12月14日, Invited talk, , 2016.

Aitaro Kato, Episodic unlocking of fault leading up to earthquake, EARTHQUAKES: nucleation, triggering, rupture, and relationships to aseismic processes, Cargese, Corsica (France), 2017, Oct. 2-6, Invited lecturer, , 2017.

Aitaro Kato, Slip towards the surface new insights from recent crustal earthquakes in Japan, workshop on Frontiers in Studies of Earthquakes and Faults, SUSTech, Shenzhen in China, 2017, Nov. 27 - Dec. 1, Invited talk, , 2017.

Aitaro Kato, The evolution of fault slip rate prior to earthquake: The role of slow and fast slip modes, International School of Physics "Enrico Fermi", Course 202 - Mechanics of Earthquake Faulting, Varenna, Italy, 2018, July 2-7, Invited lecturer, , 2018.