IAG-IASPEI 2017

Presentation information

Oral

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

[S05-1] Preservation and usage of analog seismogram archives I

Fri. Aug 4, 2017 8:30 AM - 10:00 AM Room 403 (Kobe International Conference Center 4F, Room 403)

Chairs: Emile Okal (Northwestern University) , Paul Richards (Columbia University, New York)

9:45 AM - 10:00 AM

[S05-1-06] The current status of archives of the old analog seismograms in Japan, and some examples of their preliminary contribution to seismology

Ritsuko S. Matsu'ura1, Norihito Umino2, Yoshiaki Tamura3, Yoshihisa Iio4, Minoru Kasahara5 (1.Association for the Development of Earthquake Prediction, Tokyo, Japan, 2.Tohoku University, Sendai, Japan, 3.National Astronomical Observatory of Japan, Mizusawa, Japan, 4.Kyoto University, Uji, Japan, 5.Hokkaido University, Sapporo, Japan)

invited

Since 2004, we have been cooperating to make digital image archives of old analog seismograms preserved in the following institutes:
National Astronomical Observatory of Japan, Mizusawa (records of Latitude Observatory), Tohoku University (records of Mukaiyama Observatory, and Yagiyama Seismological Observatory), and Kyoto University (Kamigamo Observatory, Abuyama Observatory, and Aso Volcanological Observatory) are mainly for smoked paper-seismograms.
Hokkaido University (Urakawa Seismological Observatory, Sapporo Center, and some temporal stations), and Earthquake Research Institute, the University of Tokyo (Tsukuba Observatory, and Dodaira Observatory) are mainly for 35mm film-seismograms and ink-recorded seismograms recorded after 1960's.
We also made the digital image archive of world seismograms on 1933 Showa Sanriku Earthquake, which were collected by the late Prof. Takeo Matsuzawa soon after the event. Although most archives are still under construction, here we would like to show our current achievement and some examples of their primitive usage.
Although we have the very good earthquake catalogue in Japan for the period from 1885, there still remain some earthquakes of questionable hypocenters and magnitudes for old events. 1911 off the Kikaijima Island earthquake of M8.0 is one of these events. It was felt even in Osaka, separated nearly 900 km from the epicenter. Gutenberg (1954) assigned 160km depth to this event. However, tsunami damage was reported in some nearby islands. When we could compare a seismogram recorded in Mizusawa of 1911 event with that of the 1901 shallow event of M7.0, whose epicenter is very close to the 1911's, it is really easy to conclude that the both events are shallow. It was confirmed by some seismograms preserved in abroad, too. We will report some other examples of the power of digital image archives of old analog records.
We appreciate the late Prof. Motoya, and many persons who have involved in the archiving operations.