Database of reflection surveys in Japan and pattern of active faults in seismic reflection profile

After the 1995 Hyogoken-Nanbu earthquake, the Minister of Education, Culture, Sports, Science and Technology have funded subsidy for local governments to survey active faults. By the end of 2001, 90 faults have been surveyed by local governments. We collected 84 seismic reflection profiles obtained by these surveys and made a database. The database recorded names, locations, sense of faults, and geological conditions of the seismic reflection profiles. We divided faults’appearance of these profiles into eight types according to the pattern of reflection surfaces in the reflection profiles ; that is, faults are recognized as (1) step (13 profiles), (2) scarp (37 profiles), (3) discontinuity of reflection surfaces (4 profiles), (4) step and scarp (20 profiles), (5) step and discontinuity of reflection surfaces (1 profile), (6) step and reflector of fault plane (3 profiles), (7) scarp and reflector of fault plane (3 profiles), and (8) discontinuity of reflection surfaces and reflector of fault plane (3 profiles). Most of reflection profiles of (1), (2), (4), (6) and (8) types are obtained across reverse faults. So, these results mainly reflect characteristics of reverse faults

Data Retrieval System of JMA Analog Seismograms in the Headquarters for Earthquake Research Promotion of the Japanese Government

Abstract To archive precious analog seismograms of major earthquakes that occurred in and around Japan, we have scanned selected analog seismograms from 113 stations deployed by the Japan Meteorological Agency (JMA) and are constructing a database of the scanned digital images accessible through the website of the Headquarters for Earthquake Research Promotion (HERP) of the Japanese government. This project started in 2006 and was conducted by the Association for the Development of Earthquake Prediction. The database of HERP now contains more than 185,000 digital images of seismograms recorded during the period from 1884 to 1995. It includes seismograms of earthquakes that occurred in and around Japan and of some major teleseismic earthquakes. The oldest analog seismogram was recorded on 2 January 1884 at a station in Tokyo. The seismograms are the intellectual property of mankind, and the database of these digital images will be an important material for studies of past destructive earthquakes. Technological progress such as artificial intelligence image recognition technology will help to further explore the data.</jats:p

Extensive damages caused by the M9 Tohoku Earthquake and the post-earthquake restoration of the seismic observation system of the Research Center for Prediction of Earthquakes and Volcanic Eruptions， Tohoku University

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