Global Seismographic Network

Map showing GSN station locations marked by a star

The Global Seismographic Network (GSN) is a 152 station, globally distributed, state-of-the-art digital seismic network that provides free, realtime, open access data through the SAGE Facility DMC. The map above shows the distribution of the current station network with respect to network code.

The Global Seismographic Network is a cooperative scientific facility operated jointly by the National Science Foundation (NSF) and the U.S. Geological Survey (USGS), coordinated with the international community, to install and operate a global, multi-use scientific facility as a societal resource for Earth observations, monitoring, research, and education. The NSF component is part of NSF’s NSF SAGE facility, operated by EarthScope Consortium under Cooperative Support Agreement EAR-1851048. The stations of the GSN attempt to obtain the best possible recording capability, balanced with global geographic coverage. GSN instrumentation measures and records with high fidelity all seismic vibrations possible from high-frequency, strong ground motions near an earthquake to the slowest global Earth oscillations excited by great earthquakes. Seismology has been the primary focus in the creation of the GSN, but the infrastructure is inherently multi-use and can be extended to other disciplines.  Several GSN stations currently incorporate microbarographs, GPS, Geomag, and Meteorological packages.

The management and operation of the GSN utilizes a unique model. EarthScope, with funding from the National Science Foundation, provides overall management and oversight for the GSN. EarthScope provides a subaward to Project IDA (International Deployment of Accelerometers) at the University of California, San Diego, to operate 40 stations of the network. Another 99 stations are operated by the USGS, who utilizes the overall program management and governance of EarthScope. The remaining 13 stations are part of an affiliated network meeting the design goals of the GSN, but operated outside the NSF/USGS funding. This blended model of network operation allows the GSN to leverage a variety of international partnerships, both government and private, where collaborations can develop directly through interactions with US government agencies or be conducted at the university level. The current distribution of stations is optimized to take full advantage of these two operational models, while ensuring that many of the decades-long relationships between operators and hosts are protected, stabilized, and sustained. Further, the GSN partnership encourages a robust evolution of technology and network operations best practices, since both groups work towards the most efficient technical developments followed by ideas sharing to achieve standardized operations. Community oversight of the GSN is provided by a standing committee made up of seismologists from EarthScope member institutions and the international community, with participation by our network operators and major agencies as observers.

The GSN is the U.S. contribution towards global, uniform, unbiased Earth coverage by a permanent network of broadband, three-component digital stations. GSN is coordinated internationally within the International Federation of Digital Seismograph Networks (FDSN), of which EarthScope is a founding member.

GSN equipment is based on the GSN Design Goals document developed and coordinated with the GSN Standing Committee and the EarthScope Instrumentation Committee. GSN makes every effort to take advantage of a broad mix of available telecommunication technologies, using public and private Internet links, and dedicated satellite circuits.

The GSN, together with the USGS National Earthquake Information Center (NEIC), are principal global sources of data and information for earthquake locations, earthquake hazard mitigation, and earthquake emergency response. In collaboration with National Oceanic and Atmospheric Administration (NOAA) Tsunami Warning Center, Japanese Meteorological Agency (JMA), and the Australian Tsunami Warning System, the GSN provides essential data for tsunami warning response globally. The GSN works closely with the International Monitoring System (IMS) for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), where nearly 30 GSN stations are now linked directly to the CTBTO International Data Centre. The GSN is an official observing system within the Global Earth Observing System of Systems (GEOSS).