This year,the Global Seismographic Network

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2004
• Subjects: Pacific; South Pole; South pole; Siberia
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.65.8236; http://ciei.colorado.edu/geophysics/pubs/mhrpubs/pubs/2004/7.pdf

(GSN) surpassed its 128-station design goal for uniform worldwide coverage of the Earth.A total of 136 GSN stations are now sited from the South Pole to Siberia,and from the Amazon Basin to the sea floor of the northeast Pacific Ocean—in cooperation with over 100 host organizations and seismic networks in 59 countries worldwide (Figure 1). Established in 1986 by the Incorporated Research Institutions for Seismology (IRIS) to replace the obsolete, analog Worldwide Standardized Seismograph Network (WWSSN), the GSN continues a tradition in global seismology that dates back more than a century to the network of Milne seismographs that initially spanned the globe.The GSN is a permanent network of state-of-the-art seismological and geophysical sensors connected by available telecommunications to serve as a multi-use scientific facility and societal resource for scientific research, environmental monitoring, and education for our national and international community. All GSN data are freely and openly available via the Internet both in real-time and from archival storage at the IRIS Data Management System (www. iris.edu). GSN instrumentation is capable of measuring and recording with high fidelity all of Earth’s vibrations, from high-frequency, strong ground motions near an earthquake, to the slowest free oscillations of the Earth (Figure 2). GSN seismometers have recorded both the greatest earthquakes on scale (for example, the 1994 Mw-8.2 Bolivia earthquake at 660 km depth; Wallace [1995]),as well as the nano-earthquakes (M < 0) near the sea floor at the Hawaii-2 Observatory [Butler, 2003]. GSN sensors are accurately calibrated, and timing is based on GPS clocks. The primary focus in creating the GSN has been seismology.However,the power,telemetry, site,and logistical infrastructure at GSN stations