1. Seismograph Networks in Japan
NASA World Wind©
Seismograph Networks in Japan
~ Introduction of NIED Data Management Center~
Today I briefly introduce our seismograph network and data management system.
Katsuhiko Shiomi
National Research Institute for Earth Science
and Disaster Prevention, Japan
May 9, 2007

2. Outline Background of recent Japan dense seismograph array
Impact of 1995 Kobe Earthquake
Seismograph networks operated by NIED
High sensitivity seismograph network: Hi-net
Broadband seismograph network: F-net
Strong motion seismograph networks: K-NET / KiK-net
Data exchange and archive
This is outline of my talk. First, I talk about the background of recent Japanese seismograph network. Then, I introduce NIED seismograph networks and data management. Time is very limited, so introduction about strong motion seismograph is omitted.

3. Impact of 1995 Kobe Earthquake
Research for earthquake prediction (1960’s~)
Hyogoken-Nanbu (Kobe) Earthquake (Mj7.3) attacked the metropolitan area of western Japan on January 17, 1995.
More than 6,000 people were killed, and about 250,000 buildings were collapsed by this earthquake.
©NIED
Fundamental survey and observation for earthquake research (1997~)

4. Fundamental Seismic Survey and Observation for Earthquake Research
Objective:
Advancement in earthquake research to contribute to earthquake disaster mitigation.
Understanding earthquake phenomena and prediction
of its occurrence.
2) Understanding strong ground motion and its prediction.
The “Fundamental Survey and Observation for Earthquake Research” project was set up in Main object of this project is to advance earthquake research in order to contribute to earthquake disaster mitigation. To achieve this object, we have two main subjects: First, understanding earthquake phenomena and its prediction, and understanding strong ground motion and its prediction. Earthquake observations were selected as one of high-priority tasks

5. Outline Background of recent Japan dense seismograph array
Impact of 1995 Kobe Earthquake
Seismograph networks operated by NIED
High sensitivity seismograph network: Hi-net
Broadband seismograph network: F-net
Strong motion seismograph networks: K-NET / KiK-net
Data exchange and archive

6. Coverage of three kind seismographs
Strong
K-NET / KiK-net
Strong motion
seismograph
F-net
High-sensitivity
seismograph
Broadband
seismograph
Hi-net
NIED is operating three kinds of seismograph networks to observe the ground motion with various frequencies and amplitude range.
First, we introduce the high sensitivity seismograph network, called Hi-net.
Weak
Slow
Fast

7. High Sensitivity Seismograph Network
Installed at the bottom of a borehole
Three components high-sensitivity velocity seismometer
Sampling frequency: 100 Hz
Continuous data recording
WIN32 format
773 stations (April, 2007)
NIED
At each Hi-net station, three- component high-sensitivity velocity seismometer is installed at the bottom of a borehole. The depth of the borehole is 100 m or deeper. Additionally, two set of three components strong motion accelerograph are equipped: One is installed at ground surface and another is at the bottom of the borehole. This accelerograph network is called as KiK-net.
Three components accelerograph X 2
Installed both on ground surface and at the bottom of the Hi-net borehole
Event trigger recording

8. Hi-net / KiK-net Data Collection
Time Correction
GPS
Continuous Data
Transmission WS
Decimation
27bit，100Hz
Hi-net
IP-VPN Network
Velocity Seismometer
KiK-net AD
Event Trigger Recording
　24bit,　200Hz
A/D
Tsukuba
DMC
This is a cartoon about data collection from Hi-net/KiK-net station. About Hi-net, the data from seismograph is digitized and decimated at each station. We collect data continuously using IP-VPN network from each station to our data management center located in Tsukuba. KiK-net adopts an event trigger recording. When earthquake information was received, we automatically or manually call to each station and collect observed data by way of telephone line. Time mark is corrected by using the GPS signal.
Strong Motion Seismometer
(~2G)
Borehole
Each Station

9. Coverage of three kind seismographs
Strong
K-NET / KiK-net
Strong motion
seismograph
F-net
High-sensitivity
seismograph
Broadband
seismograph
Hi-net
Next, we introduce Broadband seismograph network, called F-net.
Weak
Slow
Fast

10. Broadband Seismograph Network
Installed at the end of a tunnel of 30 to 50 m long
Three components broadband (STS-1 or 2) and strong-motion seismometers
Sampling frequency: 100 Hz
Continuous data recording
SAC, SEED, WIN32
73 stations (April, 2007)
Seismographs of F-net are placed at the end of a tunnel of several tens meter long to avoid temperature and atmospheric pressure changes. The waveform data are continuously sent to NIED DMC by way of IP-VPN (Virtual Private Network).

11. Continuous Data Transmission
　F-net Data Collection
F-net
GPS
Tunnel
Continuous Data Transmission
Hi-net
A/D WS
IP-VPN Network
Decimation
27bit，100Hz
Tsukuba
DMC
This is a cartoon about the F-net data collection. Both F-net and Hi-net data are continuously collected, so we use the same data collection system.
Each Station
Both F-net and Hi-net data are continuously collected, we use the
same data collection system.

12. Outline Background of recent Japan dense seismograph array
Impact of 1995 Kobe Earthquake
Seismograph networks operated by NIED
High sensitivity seismograph network: Hi-net
Broadband seismograph network: F-net
Strong motion seismograph networks: K-NET / KiK-net
Data exchange and archive

13. Real-Time Data Exchange in Japan
Public Service
JMA
Data Service
Internet
Data Archive
Research
NIED
Education / Research
Universities
In Japan, not only NIED but JMA, National University and other institutes operate their own high sensitivity and broadband observation networks. Since 2002, we started to exchange the seismological data to share the fundamental information about seismic activity in Japan Islands. JMA determines hypocentral locations of micro-earthquakes by using all these waveform data and opens the catalog to the public. NIED collects and archives these all waveform data, and provides them to the public by using Internet.
Local Government
JAMSTEC
AIST and others…

14. Size of Continuous Data
Example of One Day Data Composition
Example of Data Size of One Day
60GB / day
NIED data: 70%
Hi-net data: 60%
22TB / year
All data (2002/06/03~) are saved on the storage system with 220 TB HDD and S-DLT
This is an example of one day data composition and size. 70% of all data is generated by NIED seismograph network. We collect waveform data about 60GB per day, so the data size of one year is 22TB. Now we operate the storage system with 220 TB HDD, and all data are saved on this storage system. Additionally we use S-DLT media as the backup.
Apr. 26, 2007

15. Request for User Registration
Our data are open to the public, in principle. However

16. Request for User Registration
We request all users to make registration to access the seismological data provided by NIED. See
In order to evaluate the efficiency of our seismic observation data,
Users should inform us about their results which
they have obtained by using our data set.
Second redistribution of our data is prohibited.
Our data are open to the public, in principle. However we request persons who want to use our data to make registration. Because we have to evaluate the efficiency of our seismic observation data to get budget for operation these seismograph network. Moreover, users should inform us of their results and we prohibit second redistribution of our data.

18. Distribution of NIED Seismograph Stations
Ryukyu-Islands
Distribution of NIED Seismograph Stations
Tsukuba
防災科研で設置している全観測点の分布
・約1600個所で観測している強震観測網/基盤強震観測網
・約70個所で観測している広帯域地震観測網
・約700個所で観測している高感度地震観測網
から構成されている．

19. Thank you very much
for your attention!