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

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.

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~)

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 1997. 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

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

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

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

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

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

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).

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.

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

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…

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

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

Request for User Registration We request all users to make registration to access the seismological data provided by NIED. See http://www.hinet.bosai.go.jp/register/ENGLISH/ 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.

http://www.bosai.go.jp/e/index.html

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．

Thank you very much for your attention!