Researcher Information

NAOI Makoto

Associate Professor

Exploring earthquake source physics through seismic activity

Department of Earth and Planetary Sciences, Earth and Planetary Dynamics


We aim to elucidate the earthquake source physics through the measurement and analysis of acoustic emission and microearthquake activities.

FieldSeismology, Earth resource engineering
KeywordEarthqyake source physics, acoustic emission, machine learning, seismicity

Introduction of Research

To investigate the preparatory process of earthquake generation, I measure and analyze very small seismic events detected by seismometers or acoustic emission sensors with higher sensitivity. I have conducted observations and experiments in environments where high-quality data can be obtained, such as a deep gold mine in South Africa and laboratory experiments. In addition, taking advantage of recent rapid developments in the field of information science, I am also conducting research to make more effective use of AI techniques in the analysis of microseismic and acoustic emission data.

Hydraulic fracturing experiments and acoustic emission measurement in the laboratory.
Photograph taken in front of a shaft cage at a South Africal gold mine

Representative Achievements

Makoto Naoi, Keiichi Imakita, Youqing Chen, Kazune Yamamoto, Rui Tanaka, Hironori Kawakata, Tsuyoshi Ishida, Eiichi Fukuyama, Yutaro Arima (2022) Source parameter estimation of acoustic emissions induced by hydraulic fracturing in the laboratory, Geophys. J. Int, 231, 408–425.
Makoto Naoi, Youqing Chen, Kazune Yamamoto, Yuya Morishige, Keiichi Imakita, Naofumi Tsutumi, Hironori Kawakata, Tsuyoshi Ishida, Hiroyuki Tanaka, Yutaro Arima, Shigehiro Kitamura, Daisuke Hyodo (2020) Tensile dominant fractures observed in hydraulic fracturing laboratory experiment using eagle ford shale, Geophys. J. Int., 222, 769–780.
M. Naoi, M. Nakatani, H. Moriya, and Y. Yabe (2016) Acoustic emission monitoring for mitigating seismic risks in deep gold mines in south africa, International Journal of the JSRM, 12, 19-22.
M. Naoi, M. Nakatani, T. Igarashi, K. Otsuki, Y. Yabe, T. Kgarume, O. Murakami, T. Masakale, L. Ribeiro, A. Ward, H. Moriya, H. Kawakata, S. Nakao, R. Durrheim, H. Ogasawara (2015) Unexpectedly frequent occurrence of very small repeating earthquakes (–5.1 ≤ MW ≤ –3.6) in a South African gold mine: implications for monitoring intraplate faults, J. Geophys. Res., 120, 8478–8493.
Academic background2005 Department of Physical Sciences, Retsumeikan University
2007 M.Sc., Graduate School of Science and Engineering, Retsumeikan University
2010 Ph.D., School of science, The University of Tokyo
2007-2010 Research Fellow of the Japan Society for the Promotion of Science (DC1)
2010-2014 Project Researcher, Earthquake Research Institute, The University of Tokyo
2014-2018 Assistant Professor, Graduate School of Engineering, Kyoto University
2019-2023 Assistant Professor, Disaster Prevention Research Institute, Kyoto University
2024- Associate Professor, Faculty of Science, Hokkaido Univerity
Affiliated academic societySeismological Society of Japan, Japan Geosciences Union, Japanese Society for Rock Mechanics, The Japanese Society for Artificial Intelligence
Room addressScience Building 8 8-312