Seismograph Networks in China: Present State and Development Program Yun-tai Chen, Gong-wei Zhou and Rui-feng Liu Institute of Geophysics China Earthquake Administration Beijing , China Beijing , China August 24, 2005 Washington DC

China Digital Seismograph Network (CDSN) Sino-US cooperativeSino-US cooperative Designed in 1983Designed in 1983 Started operation in 1986Started operation in 1986 Upgraded in1993 to 2001Upgraded in1993 to 2001 A main partner of GSNA main partner of GSN

China Digital Seismograph Network

A national project Launched by CEA for updating the seismological observation facilities into digital seismological observation systems Supported by the central government and local governments China Digital Seismological Observation System (CDSOS) ( )

China Digital Seismological Observation System (CDSOS) National Digital Seismograph Network (NDSN) 48 real-time digital seismic stations through satellite links 28 auxiliary stations by CD Regional Digital Seismograph Network (RDSN) Regional Telemetered Digital Seismograph Networks (RTDSN) 20 Networks with 267 stations Telemetered Digital Seismograph Network in Capital region: 107 stations Portable Digital Seismograph Network (PDSN) 100 portable stations

National Digital Seismograph Network (NDSN) (48 real-time stations) Legend

National Digital Seismograph Network (NDSN) (28 auxiliary stations)

Regional Digital Seismograph Network (RDSN) (20 networks with 267 stations) Legend Network center Telemetered station

Telemetered Digital Seismograph Network in Capital Region (107 stations) Beijing Tianjin Hebei

The Monitoring Capability of Digital Seismic Telemetered Stations in Capital Region VBB BB Bore hole Solidl: w. SM

Instruments National Digital Seismograph Network (NDSN) JCZ-1: flat velocity response from 360 s to 20 Hz, sampling rate: 50 sps CTS-1: flat velocity response from 120 s to 20 Hz, sampling rate: 50 sps STS-1: flat velocity response from 360 s to 8.5 Hz, sampling rate: 20 sps Regional Telemetered Digital Seismograph Networks (RTDSN) FBS-3: flat velocity response from 20 s to 20 Hz, sampling rate: 50 sps FSS-3: flat velocity response from 1s to 20 Hz, sampling rate: 50 sps Portable Digital Seismograph Stations FSS-3: flat velocity response from 1s to 20 Hz, sampling rate: 50 sps

China Digital Seismological Observation System (by the end of 2005) National Digital Seismograph Network (NDSN) Real-time digital seismic stations through satellite links: 152 stations (now 48) Regional Telemetered Digital Seismograph Networks (RTDSN) 31 Networks (now 20) with 678 stations (now 267) Portable Digital Seismograph Stations 800 stations (now 100)

(152 stations by the end of 2005) National Digital Seismograph Network (152 stations by the end of 2005) To be installed Existing Legend

Regional Digital Seismograph Network (678 stations by the end of 2005)

Development Program ( ) For studies of global seismicity (72 stations) 24 existing stations 24 existing stations 7 stations by the end of stations by the end of stations will be established in stations will be established in stations and 5 seismic arrays with spacing between stations of km. by the end of 2005: 150 stations and 2 arrays by the end of 2005: 150 stations and 2 arrays In Tibetan Plateau, the spacing between the stations will be about 400km.

Development Program ( ) Regional telemetered digital seismograph networks In the most densely populated and/or earthquake- prone areas of China will be greatly intensified. In the most densely populated and/or earthquake- prone areas of China will be greatly intensified. Existing: 785 ( ) regional stations Existing: 785 ( ) regional stations By the end of 2005:1000 regional stations By the end of 2005:1000 regional stations : 1689 regional stations : 1689 regional stations Spacing between stations: about 10km Spacing between stations: about 10km : 4000 strong motion stations : 4000 strong motion stations.

Development Program ( ) Monitoring seismicity associated with mining activity, reservoir, nuclear power plant, oil-field, etc. Monitoring seismicity associated with mining activity, reservoir, nuclear power plant, oil-field, etc. Denser spaced seismograph networks sponsored and operated by industrial agencies are considered to be important supplements to the NDSN and to the regional telemetered digital seismograph networks. Denser spaced seismograph networks sponsored and operated by industrial agencies are considered to be important supplements to the NDSN and to the regional telemetered digital seismograph networks.

谢谢！ Thank you! Спасибо!