On 1 October 1997, the Japan Meteorological Agency (JMA) adopted new operational procedures in collaboration with the Ministry of Education, Culture, Sports, Science and Technology to analyze seismic wave data provided by cooperative organizations*. This step was taken in line with the Act on Special Measures concerning Earthquake Disaster Management, which was enacted to promote seismological research in light of lessons learned from the 1995 Great Hanshin-Awaji (Hyogoken-Nanbu) Earthquake. Products created using the new procedures have been submitted to the Earthquake Research Committee, which was established under the provisions of the prescribed act, and utilized for comprehensive assessment of seismic activity in and around Japan.
This bulletin highlights seismological data processed in this way, including earthquake source parameters, arrival time data and source mechanism solutions. All data are based on the Japanese Geodetic Datum 2000, and Japan Standard Time (JST) notation is used.
The bulletin also details seismic intensity and maximum acceleration data, tsunami data and the up-to-date JMA event catalogue (1919–). Seismic intensity is now measured automatically with dedicated meters installed by JMA, local public bodies**and the National Research Institute for Earth Science and Disaster Prevention.
* Data provided by the National Research Institute for Earth Science and Disaster Prevention, Hokkaido Univ., Hirosaki Univ., Tohoku Univ., The Univ. of Tokyo, Nagoya Univ., Kyoto Univ., Kochi Univ., Kyushu Univ., Kagoshima Univ., the National Institute of Advanced Industrial Science and Technology, the Geospatial Information Authority of Japan, the Japan Agency for Marine-Earth Science and Technology,Association for the Development of Earthquake Prediction, Aomori Pref., the Tokyo Metropolitan Government, Shizuoka Pref., the Hot Springs Research Institute of Kanagawa Prefecture, Group for urgent joint seismic observation of the 2016 Kumamoto earthquake, and Incorporated Research Institutions for Seismology. (As of March 2023)
** The Hokkaido Government, Aomori Pref., Iwate Pref., Miyagi Pref., Akita Pref., Yamagata Pref., Fukushima Pref., Ibaraki Pref., Tochigi Pref., Gunma Pref., Saitama Pref., Chiba Pref., the Tokyo Metropolitan Government, Kanagawa Pref., Niigata Pref., Toyama Pref., Ishikawa Pref., Fukui Pref., Yamanashi Pref., Nagano Pref., Gifu Pref., Shizuoka Pref., Aichi Pref., Mie Pref., Shiga Pref., Kyoto Pref., Osaka Pref., Hyogo Pref., Nara Pref., Wakayama Pref., Tottori Pref., Shimane Pref., Okayama Pref., Hiroshima Pref., Yamaguchi Pref., Tokushima Pref., Kagawa Pref., Ehime Pref., Kochi Pref., Fukuoka Pref., Saga Pref., Nagasaki Pref., Kumamoto Pref., Oita Pref., Miyazaki Pref., Kagoshima Pref., Okinawa Pref., Sendai City (Miyagi Pref.), Yokohama City (Kanagawa Pref.), Kawasaki City (Kanagawa Pref.) and Nagoya City (Aichi Pref.) (As of March 2023)
Some figures were generated using the Generic Mapping Tool [Wessel, P. and W. H. F. Smith, Free software helps map and display data, EOS Trans. AGU, 72, 441, 445 – 446, 1991].