Monitoring Earthquakes Across the United StatesMonitoring Earthquakes Across the United States T...
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Earthquake data from the U.S. National Seismograph Network and other stations feed into USGS computers, located in Golden, Colo., via satellite transmissions and through the Internet. information. The United States National Seismograph Network (USNSN), operated by the USGS, provides uniform coverage of the whole Nation and integrates data from the regional networks. The NEIC rapidly reports earthquakes to Federal, State, and local emer- gency managers, public utilities, the media, and the public. The RSN’s fulfill a similar role within their regions. The cooperation and coordination of the RSN’s and the USNSN is organized through the Council of the National Seismic System (CNSS), of which the USGS is the steward. Understanding Earthquake Hazards Across the United States M ore than 2,500 seismograph stations monitor earthquakes throughout the conterminous United States, Alaska, and Hawaii. The stations are grouped into regional networks operated by local institutions. The U.S. Geological Survey (USGS) supports many of these regional networks and operates its own nationwide network. The regional seismograph networks (RSN’s) provide infor- mation about earthquakes to the USGS National Earthquake Information Center (NEIC) in Colorado, which serves as a nation- al point of contact for distributing earthquake Monitoring Monitoring Earthquakes Earthquakes Across the United States Across the United States T hose who plan for and respond to earthquake disasters, and those who study earthquakes, require timely notification of earthquake occurrences and informa- tion to mitigate losses. Earthquake events throughout the United States are cur- rently monitored by sophisticated systems that provide the notification and information needed by decision makers before and during times of crisis. The national and regional earthquake monitoring systems for the United States have evolved into one of the world’s finest emergency-management and research tools. USGS Fact Sheet 146-97 USGS Fact Sheet 146-97 1997 1997 U.S. Department of the Interior U.S. Geological Survey
Transcript of Monitoring Earthquakes Across the United StatesMonitoring Earthquakes Across the United States T...
Earthquake data from theU.S. National SeismographNetwork and other stationsfeed into USGS computers, located in Golden, Colo., viasatellite transmissions and through the Internet.
information. The United States NationalSeismograph Network (USNSN), operated bythe USGS, provides uniform coverage of thewhole Nation and integrates data from theregional networks. The NEIC rapidly reportsearthquakes to Federal, State, and local emer-gency managers, public utilities, the media,and the public. The RSN’s fulfill a similar rolewithin their regions. The cooperation andcoordination of the RSN’s and the USNSN isorganized through the Council of the NationalSeismic System (CNSS), of which the USGSis the steward.
Understanding Earthquake Hazards Across the United States
More than 2,500 seismograph stationsmonitor earthquakes throughout the
conterminous United States, Alaska, andHawaii. The stations are grouped into regionalnetworks operated by local institutions. TheU.S. Geological Survey (USGS) supportsmany of these regional networks and operatesits own nationwide network. The regionalseismograph networks (RSN’s) provide infor-mation about earthquakes to the USGSNational Earthquake Information Center(NEIC) in Colorado, which serves as a nation-al point of contact for distributing earthquake
MonitoringMonitoring EarthquakesEarthquakesAcross the United StatesAcross the United States
T hose who plan for and respond to earthquake disasters, and those who studyearthquakes, require timely notification of earthquake occurrences and informa-tion to mitigate losses. Earthquake events throughout the United States are cur-
rently monitored by sophisticated systems that provide the notification and informationneeded by decision makers before and during times of crisis. The national and regionalearthquake monitoring systems for the United States have evolved into one of theworld’s finest emergency-management and research tools.
USGS Fact Sheet 146-97USGS Fact Sheet 146-9719971997
U.S. Department of the InteriorU.S. Geological Survey
The USNSN determines the location andmagnitude of significant earthquakes any-where in the United States within minutes,while the RSN’s provide this information forearthquakes in their regions within seconds.Together, the RSN’s and the USNSN provide(1) comprehensive, reliable, and cost-effectiveearthquake monitoring of the Nation, (2)highly accurate recordings of even the largestearthquakes, and (3) high-resolution mappingof faults in seismically active areas. In theaftermath of a major earthquake, theUSGS/NEIC and the RSN’s rapidly provideearthquake information, including detailedinterpretations to assist disaster-responseactivities. The USGS/NEIC uses the USNSNto assist other Federal agencies in tsunamiwarnings, overseeing nuclear powerplantsafety during earthquakes, and discriminatingnuclear blasts from earthquakes undernuclear- test-ban agreements.
SEISMIC MONITORING• Real-time hazards information for emer-
gency management and the general public• General information for public officials,
utilities, the engineering community, andthe media
• Earthquake catalog for earthquake hazardsassessments
• Seismic waveform archive for applied andbasic research
National Component (USNSN)• National real-time advisories within
minutes• Uniform earthquake monitoring of the
Nation• Precise recordings of medium to large
earthquakes
Regional Component (RSN’s)• Regional real-time advisories within
seconds• Detailed monitoring of earthquake-prone
areas• Precision mapping of faults• Local expertise on earthquake hazards to
increase public awareness and safety
Each USNSN stationconsists of a systemof sophisticatedseismometers, data-acquisition system,and satellitetelecommunicationsequipment. USNSNstations providehigh-quality, real-time information onearthquake occur-rences directly tothe USGS NationalEarthquakeInformation Center(NEIC) in Coloradoand to cooperatorsthroughout the network.
For the Nation,seismic moni-toring offers awide variety ofbenefitsfocused onminimizingloss of life andproperty thatresult fromearthquakes,and under-standing earth-quake phe-nomena forearthquake-hazardsplanning.
USNSN StationsUSNSN Stations (Planned)
Cooperating StationsCooperating Stations (Planned)
USNSN Stations
This seismogram of a magnitude 5.0 aftershock of the 1994Northridge, California, earthquake was recorded at aUSNSN station in Tonopah, Nevada. The P-wave (travelingrapidly through the Earth) was recorded first; the S-wave(traveling more slowly through the Earth) was recordedabout 40 seconds later and produced significantly strongerground vibrations. Seismograms from many stations thatrecord the same event allow scientists to determine suchfactors as the time, location, type of faulting, and energyrelease of an earthquake.
Advanced seismic sensors (inset) areinstalled at USNSN sites to measure Earthmovements.
Distributing Uniform EarthquakeInformation Nationwide
The USGS and the RSN’s are currently devel-oping agreements on common methods, for-mat, and procedures for reporting earthquakeinformation. This ongoing program effective-ly integrates the USNSN and the RSN’s into asingle National Seismic System. Part of thiseffort includes acquiring and developing newsoftware to connect all seismograph networksacross the Nation. Earthquake data from anynetwork then will be immediately available toall networks nationwide. For example, arequester in New York will be able to obtainimmediate information on an earthquake inOregon from a local RSN in New York, ratherthan trying to communicate with a more dis-tant RSN.
Activities of the seismograph networksnationwide are coordinated by the Council ofthe National Seismic System (CNSS), whichfosters development and cooperation forimproved regional and national earthquakereporting. Details about the CNSS and itsmember seismograph networks may beviewed on the World Wide Web (WWW) atthe following Uniform Resource Locator(URL):
http://www.cnss.org/
Current earthquake activity is posted directlyto the WWW as earthquakes occur. Locationsof important earthquakes nationwide arereviewed by analysts and listed on the WWWwithin about an hour. In other areas, notablycentral California, earthquake locations auto-matically appear on the WWW in about aminute. Examples, which include a variety ofearthquake parameters, and maps of epicen-ters, can be viewed on the WWW at the fol-lowing URL’s:
http://quake.wr.usgs.gov/recenteqs
http://wwwneic.cr.usgs.gov/
P-wave
S-wave
0 50 seconds
For more information contact:U.S. Geological Survey
National Earthquake Information Center(303) 273-8500Mailing address:
Federal Center, Box 25046, MS 967Denver, CO 80225-0046 USAhttp://wwwneic.cr.usgs.gov/
University of Utah Seismograph Stations,Salt Lake City
University of Washington, SeattleU.S. Advanced Research Projects AgencyU.S. National Park Service, Yellowstone
National ParkU.S. Nuclear Regulatory CommissionU.S. Air Force Technical Applications Center,
Patrick Air Force Base, FloridaU.S. Bureau of ReclamationU.S. Department of Energy, Sandia National
LaboratoriesVirginia Polytechnic Institute and State
University Seismological Observatory,Blacksburg
West Coast/Alaska Tsunami Warning Center,Palmer, Alaska
Wyoming Geological Survey, Laramie
Boston College, Weston, Mass.California Institute of Technology, PasadenaDelaware Geological SurveyIncorporated Research Institutions for
SeismologyLamont-Doherty Earth Observatory of
Columbia UniversityLawrence Livermore National LaboratoryPacific Tsunami Warning Center, Ewa Beach,
HawaiiSaint Louis University, Saint Louis, Mo.University of Alaska, FairbanksUniversity of California, San DiegoUniversity of California, BerkeleyUniversity of MemphisUniversity of Nevada, RenoUniversity of North Carolina at Chapel HillUniversity of South Carolina
The USGS supports the regional seismograph networks (RSN’s) that monitor the areas of the United States out-lined in red. Other RSN’s are self-supporting. The Council of the National Seismic System (CNSS) coordinatesactivities of the RSN’s and the United States National Seismiograph Network (USNSN). White circles indicate mag-nitude 2.0 and greater earthquakes recorded between July 1995 and August 1996.
Regional Seismograph Networks
The USGS and itscooperators havebeen steadilydeveloping thisvast, intercon-nected monitor-ing and commu-nications systemfor many years.Continually usingtechnologicaladvances toimprove the sys-tem and interpretthe information itproduces, USGSearth scientistsare serving pri-mary needs forthe Nation’sapproach andresponse toearthquakehazards.
ByRaymond P. Buland, Harley M. Benz, and
William M. Brown III
Graphic design byEleanor M. Omdahl and Margo L. Johnson
Cooperating Organizations
