6-7j@Earthquake
Information Center (EIC)
Earthquake Information Center (EIC) has a central role of
Japan University Network for the Earthquake Prediction Program, making archives
of all seismic data observed in Japan.
EIC also creates a database and develops software to analyze the
database.
To utilize this database, EIC coordinates various
collaborative projects among domestic and international researchers, concerning
the source process of earthquakes and tsunamis, real-time seismology, and the
communication system for earthquake information.
<<Earthquake Information Network>>
Japan University Network Earthquake Catalog
(JUNEC)
The data obtained from the observation networks of the
earthquake prediction information have been combined for alignment by the newly
inaugurated Japan University Network Earthquake catalogue (JUNEC). The data are
made available by CD-ROM since 1999 (Fig.1).
Fig.1.
Distribution of earthquakes determined by JUNEC(1985-1998) and CD-ROM.
Communication Network of Seismic Data
(http://jarray.eri.u-tokyo.ac.jp/)
EIC has been engaged in developing access systems for a
waveform database to provide every researcher with the seismic waveform
database via the Internet. Using this system, data gathered by the center are
publicized as new J-array seismic waveform data, and are available via the WWW
(Fig. 2).
Taking account of the fact that a satellite telemetry
system started operation to make data available to every researcher, all of the
new J-array waveform data have been compiled in EIC since March 1998.
Fig.2. J-array
broadband waveform data of the 2002 Alaska earthquake.
Parallel computer
(http://wwweic.eri.u-tokyo.ac.jp/computer/)
Parallel computer SGI Origin
2000 System that consists of 64 CPU's was introduced in March 1999. The
capacity is drastically improved by this system, and it is possible to
calculate the large-scale simulation. Now the CPU working rate in the monthly
is daily utilized to the limit to the capacity with 80-90% (Fig. 3). It is
required urgently to increase the capacity.
Fig.3. Change of CPU utility time of the parallel computer.
EIC newsletter
(http://wwweic.eri.u-tokyo.ac.jp/NEWSLETTER/)
To support smooth notification of the users of the
center, the EIC newsletter has been published almost once per two months since
December 1997. Edition No.20 was issued in January 2001. The edition contains
information concerning usable resources such as software and database, users'
activity, and seismological information.
<< Real-time Seismology >>
Quick
information about earthquake source and strong ground motion is obtained by
analyzing quasi real-time seismic data, which can support a prompt emergency
response to mitigate earthquake hazards.
Special Home Page for large earthquakes
For large and damage earthquakes or volcanic eruption,
our analytical results have been published on Special HP (Fig. 4). CMT
solutions ("ERI Auto CMT solutions") by automatically using waveform
data from IRIS-DMC are also published on Special HP.
Fig4. Special
Event Page (Dec.18, 2001 Yonaguni-jima Earthquake).
EIC Seismological Note
(http://wwweic.eri.u-tokyo.ac.jp/EIC/EIC_News/)
For interesting earthquakes such as those with the
magnitude greater than seven or those believed to be important regardless of
their magnitude, the rupture process of the earthquake source is analyzed using
teleseismic body waves. The results are edited for publication with the title
"EIC Seismological Note".
Seismic Kanto Strong Motion Network
After the 1995 Kobe Earthquake, local governments
installed strong motion seismometers and seismic intensity meters in
metropolitan area. EIC constructed the system "Seismic Kanto Strong Motion
Network" which collects these strong motion waveform data by getting cooperation
with local governments. The network covers a wide area (the Kanto area) with
high density (450 observation stations) (Fig.5). ).
Fig.5. Seismic Kanto Strong Motion Network
home page.
<<Old Seismographs and Seismological
Bulletins>>
EIC preserves many historical seismograms recorded at
Hongo, Tokyo, from 1899 to 1942. The preserved seismograms reach the 200,000
sheets. The seismograms were copied on microfilms. Database retrieval system of
these seismograms has also been constructed. EIC also preserves records of the World-Wide Standardized
Seismograph Network (WWSSN) from 1978 to 1988 in the form of 35mm films and
microfiches. In addition, many old seismological bulletins such as the
International Seismological Center and other foreign observatories, are
maintained by the Earthquake Information Center and the Earthquake Prediction
Research Center.
Fig.6. Northern Izu Earthquake of Nov.
26,1930 recorded at Hongo, Tokyo.