Monitoring and responding to earthquakes and tsunamis requires high-quality observational networks. These monitoring systems can detect earthquakes, tsunamis, landslides, volcanoes and other naturally occurring events, as well as human-made events like mine collapses and explosions.
The United States maintains several key elements to global and national monitoring programs:
- The Global Seismographic Network (GSN) provides real-time data from more than 150 stations with state-of-the-art seismological and geophysical sensors. Formed in partnership between the U.S. Geological Survey (USGS) and the National Science Foundation (NSF) and operated by the Incorporated Research Institutions for Seismology, the GSN provides near-uniform monitoring of the Earth and provides significant societal benefits.
- The Advanced National Seismic System (ANSS) is comprised of a national backbone network and 15 networks focused on specific regions of the country. This statutory program between the USGS and state and regional earthquake monitoring organizations permits the rapid dissemination of key information to the public, news media and emergency response personnel. The ANSS, a vital component of the National Weather Service’s domestic tsunami warning program, is also used to track seismicity related to oil, gas and mining activities.
In addition, the United States has thousands of accelerometers sited to record strong ground motions near active faults, coastal and deep ocean sea level sensors to detect tsunamis, and GPS networks and satellite systems to monitor crustal deformation. The U.S. contributes to the International Monitoring System (IMS) sensor network designed to detect and characterize nuclear explosions worldwide.
Continued operation of all of these instruments and networks is vital for hazard monitoring and emergency response, as well as providing multi-use scientific facilities for continued research and education. Analysis and distribution of these data and resulting data products require facilities operating at the national and regional level with strong computing resources and experienced personnel. Some key data products include:
- ShakeMap: shows in near real-time the distribution of observed and estimated ground shaking, a key resource for emergency response and planning.
- Seismic Hazard Maps: provide estimated probabilities of strong ground shaking to help with response efforts after an earthquake, and are used to inform infrastructure design.
- Earthquake Early Warning Systems: currently in a testing stage in the US, can provide valuable seconds upto a minute of advance warning of shaking from an earthquake, which can enable automated systems to prevent gas fires, train collisions and other deadly repercussions.
- Tsunami warnings: protect lives by enabling effective evacuations, and speed economic recovery by allowing marine operators to take actions to protect ships and ports, thanks partly to alerts based on seismic data before a tsunami is directly measured.
These established and enhanced observing systems are critical to reducing the human and economic costs of natural hazards, enhancing education, mitigation and preparedness, improving response and limiting the long-term consequences of hazards.
The Seismological Society of America strongly recommends that Congress continue to support earthquake and tsunami monitoring to ensure the continuation of these critical programs.
Approved by the SSA Board of Directors, December 2017