IAG-IASPEI 2017

講演情報

Poster

IASPEI Symposia » S05. Preservation and usage of analog seismogram archives

[S05-P] Poster

2017年8月3日(木) 15:30 〜 16:30 Event Hall (The KOBE Chamber of Commerce and Industry, 2F)

15:30 〜 16:30

[S05-P-02] HERP data retrieval system of JMA analog seismograms

Mitsuko Furumura1, Koji Iwasa1, Yasunori Suzuki1, Tomotsugu Demachi2, Takeo Ishibe1, Ritsuko S. Matsu'ura1 (1.ERC, ADEP, Tokyo, Japan, 2.Graduate School of Science, Tohoku University, Sendai, Japan)

Since 2006, we have scanned selected analog seismograms observed at about 150 stations deployed by Japan Meteorological Agency (JMA), and constructed a database of the scanned digital images.
Digital image of each seismogram is obtained by scanning the entire seismogram at once using a large flatbed color scanner with a 400 dpi resolution, and saved as a TIFF-format file. Due to the depth of focus, we can get clear seamless images even for not-flat seismograms. As of January 2017, we obtained more than 138,000 image files of seismograms recorded at 100 stations, by various types of seismographs, such as Gray-Milne-Ewing type seismograph (G.M.E), Wiechert Seismograph, and mechanical strong motion seismographs. In those data, there are many precious records of the destructive earthquakes like the 1891 Nobi earthquake.
The images of seismograms for 91 stations can be now available through the web site:
http://www.susu.adep.or.jp/
The images for the rest stations are under processing to be added to the database.
In the database, the seismograms can be searched by date, station name, and components. The size of one original TIFF-format image file is around 200 MB, then all images are highly compressed as JPEG2000 files for easy preview and download.
Constants of static magnification, natural period and other parameters of the used seismographs are also collected.
The database has begun to be utilized for research, such as re-investigation of the 1914 earthquake at Kagoshima (Ogata et al., 2016). We are planning that the web site will become one of the Wiki page, in which data of the seismograms digitized by researchers are open after getting their permission.
Acknowledgement
This project has been supported by the Headquarters for Earthquake Research Promotion (HERP) of the Ministry of Education, Culture, Sports, Science, and Technology in Japan. We thank to Dr. Masayuki Okuno, Mr. Yukio Hirai, Mr. Atsushi Kamata, and Mrs. Yoshiko Suzuki.