- AAE - Geophysical Observatory, Adis Abeba University, Ethiopia
- AAM - University of Michigan, Ann Arbor, USA
- ACI - Universita di Calabria, Cosenza, Italy
- ACP - Autoridad del Canal de Panama, Balboa-Ancon, Panama
- ADE - Primary Industries and Resources SA, Adelaide, S.A., Australia
- AGS - USGS Alaska Seismic Project, Menlo Park, California, USA
- AK - Alaska Earthquake Center (aka AEI, AEIC)
- ALG - CRAAG, Alger-Bouzareah, Algeria
- ALQ - Albuquerque Seismological Laboratory, Albuquerque, New Mexico, USA
- ANZA - Anza Seismic Network, IGPP, UC San Diego, La Jolla, California, USA
- ARO - Observatoire Geophysique d'Arta, Djibouti
- ASRS - GSRAS Siberian Branch, Altay-Sayan Seis. Ctr., Novosibirsk, Russia
- AT - National Tsunami Warning Center (aka ATWC)
- ATH - National Observatory of Athens, Greece
- ATL - Georgia Institute of Technology, Atlanta, USA
- ATX - University of Texas Institute for Geophysics, Austin, USA
- AUST - Geoscience Australia, Canberra, ACT, Australia
- AV - Alaska Volcano Observatory
- AWIB - Alfred Wegener Inst. of Polar and Marine Research, Bremerhaven, Germany
- AZER - Rep. Center of Seismic Survey, Azerbaijan Academy of Science, Baku
- AZUR - Geosciences Azur, Universite de Nice Sophia-Antipolis, Valbonne, France
- BARI - Osservatorio Sismologico, Universita degli Studi di Bari, Italy
- BASV - British Antarctic Survey, Cambridge, England, UK
- BDF - Observatorio Sismologico, Universidade de Brasilia, Brazil
- BELR - Inst. of Geochem. and Geophysics, Belarus Academy of Science, Minsk
- BEO - Seismological Survey of Serbia, Belgrade, Serbia
- BER - Institutt for geovitenskap, Universitetet i Bergen, Norway
- BGRD - Bundesanstalt fur Geowissenschaften und Rohstoffe, Hannover, Germany
- BGS - British Geological Survey, Edinburgh, United Kingdom
- BHD - Seismology Unit, Scientific Research Council, Baghdad, Iraq
- BHKY - University of Kentucky, Lexington, USA
- BHL - Conseil National de la Recherche Scientifique, Beirut, Lebanon
- BJI - China Earthquake Administration, Beijing, China
- BKK - Meteorological Department, Bangkok, Thailand
- BKN - Procurement Executive, Ministry of Defence, Blacknest, UK
- BLA - Virginia Polytechnic Institute and State University, Blacksburg, USA
- BLMY - Indian Point Network, Woodward-Clyde Consultants, New Jersey, USA
- BLY - Institute for Material Testing, Banja Luka, Bosnia and Herzegovina
- BMU - Bahrain Meteorological Service, Bahrain
- BNG - Inst. de Recherche pour le Developpement, Bangui, Cen. African Rep.
- BNS - Geologisches Inst. der Universitat Koln, Bergisch Gladbach, Germany
- BOG - Instituto Geofisico, Universidad Javeriana, Bogota, Colombia
- BOU - University of Colorado, Boulder, USA
- BRA - Geofyzikalny ustav SAV, Bratislava, Slovakia
- BRG - Seismologisches Observatorium, Berggiesshubel, Germany
- BRK - University of California, Berkeley, USA
- BRL - Freie Universitat Berlin, Berlin, Germany
- BRS - University of Queensland, Brisbane, Australia
- BSE - Boise State University, Idaho, USA
- BUC - National Institute for Earth Physics, Bucharest-Magurele, Romania
- BUD - Hungarian Seismological Institute, Budapest
- BUG - Ruhr-Universitaet, Bochum, Germany
- BUL - Goetz Observatory, Bulawayo, Zimbabwe
- BUT - Montana Bureau of Mines and Geology, Butte, USA
- BYKL - GSRAS Siberian Branch, Baykal Regional Seis. Center, Irkutsk, Russia
- BYT - Central Institute of Mines, Katowice, Poland
- CAM - Massachusetts Institute of Technology, Cambridge, USA
- CAN - Australian National University, Canberra, ACT, Australia
- CAR - FUNVISIS, Caracas, Venezuela
- CASC - Central American Seismic Center, San Jose, Costa Rica
- CAT - Instituto Scienze della Terra, Catania, Italy
- CDMG - California Division of Mines and Geology, Sacramento, USA
- CDPJ - Nat. Research Ctr for Disaster Prevention, Ibaraki-ken, Japan--now NIED
- CDR - Commissariat a l'Energie Atomique (CEA) Fontenay aux Roses, France
- CDWR - California Department of Water Resources, Sacramento, USA
- CELS - Comision Hidroelectrica del Rio Lempa, El Salvador
- CERI - Center for Earthquake Research and Information, Memphis, Tennessee
- CFF - Inst. et Observatoire de Physique du Globe, Clermont-Ferrand, France
- CGS - California Geological Survey
- CHC - University of North Carolina, Chapel Hill, USA
- CI - California Integrated Seismic Network: Southern California Seismic Network (Caltech, USGS Pasadena, and Partners) (aka PAS)
- CLL - Geophysikalisches Observatorium, Univ. Leipzig, Collm, Germany
- CNRM - Centre National de la Recherche Scient. et Tech., Rabat, Morocco
- COR - College of Oceanography, Oregon State University, Corvallis, USA
- CRT - Instituto Andaluz de Geofisica, Universidad de Granada, Spain
- CSC - University of South Carolina, Columbia, USA
- CSEM - Centre Sismologique Euro-Mediterraneen, Bruyeres-le-Chatel, France
- CSS - Geological Survey Department, Nicosia, Cyprus
- DAL - Southern Methodist University, Dallas, Texas, USA
- DBN - Koninkijk Nederlands Meteorologisch Instituut, De Bilt, Netherlands
- DDA - Directorate of Disaster Affairs, Lodumlu, Ankara, Turkey
- DESU - CADAFE, Desarrollo Uribante Caparo (DESURCA), San Cristobal, Venezuela
- DHMR - National Seismological Observatory Center, Dhamar, Yemen
- DIAS - Dublin Institute for Advanced Studies, Ireland
- DJA - Badan Meteorologi dan Geofisika, Jakarta, Indonesia
- DME - Department of Minerals and Energy, Pretoria, South Africa
- DMN - Department of Mines and Geology, Kathmandu, Nepal
- DNGM - Direccao Nacional de Geologia, Maputo, Mozambique
- DNK - Danmarks og Gronlands Geologiske Undersogelse, Copenhagen, Denmark
- DOE - US Department of Energy (and predecessors) -- explosions
- DRI - Disaster Prevention Research Institute, Kyoto University, Japan
- DRS - GSRAS, Dagestan Regional Seismological Center, Makhachkala, Russia
- DSIT - State Water Works Division (DSI), Ankara, Turkey
- DTM - Carnegie Institution of Washington, Washington, DC, USA
- DUKE - Duke Power Company, South Carolina, USA
- ECX - RESNOM, CICESE, Ensenada, Baja California, Mexico
- EDM - University of Alberta, Edmonton, Canada
- ENI - Ente Nazionale Idrocarburi, Italy
- ENT - Geological Survey and Mines Department, Entebbe, Uganda
- EPT - Kidd Seismological Observatory, University of Texas, El Paso, USA
- ERC - Centro Ettore Majorana, Erice, Italy
- ERIJ - Earthquake Research Institute, Univ. of Tokyo, Japan
- EUO - Department of Geological Sciences, University of Oregon, Eugene, USA
- EW - ShakeAlert® Earthquake Early Warning System (USGS and university partners)
- EXP - Explosion parameters from any group other than DOE or predecessors
- FBB - Geologisches Landesamt Baden-Wuerttemberg (LEDBW), Freiburg, Germany
- FDF - IPG Observatoire Geophysique, St. Pierre, Martinique
- FIR - Universita Degli Studi di Firenze, Firenze, Italy
- FLAG - Arizona Earthquake Information Center, Flagstaff, USA
- FNET - F-net Broadband Seismograph Network, University of Tokyo, Japan
- FOG - Osservatorio V. Nigri, Foggia, Italy
- FUR - Geophysikalisches Obs. der Univ. Muenchen, Fuerstenfeldbruck, Germany
- GAR - Complex Seismological Expedition, Garm, Tajikistan
- GBZT - TUBITAK, Marmara Research Center, Gebze, Turkey
- GCG - INSIVUMEH, Guatemala City, Guatemala
- GCMT - Lamont-Doherty Earth Observatory Global CMT project, New York, USA
- GEN - Dipart. Studio del Territorio e Risorse, Universita di Genova, Italy
- GEOT - Teledyne Geotech Corporation, Garland, Texas, USA
- GFU - Geofyzikalni ustav Akademie vid Ceske republiky, Praha, Czech Republic
- GFZ - GeoForschungsZentrum Potsdam, Telegrafenberg, Potsdam, Germany
- GIA - Geophysical Institute, Univ. of Alaska, Fairbanks, USA
- GII - Geophysical Institute of Israel, Lod, Israel
- GOL - Geophysics Department, Colorado School of Mines, Golden, USA
- GOM - Observatoire Volcanologique de Goma, Goma, Dem. Republic of the Congo
- GRC - Observatoire Sismologique, Garchy, France
- GRF - BGR, Zentralobservatorium Graefenberg, Erlangen, Germany
- GRN - Lab. de Geophysique Interne et de Tectonophysique, Grenoble, France
- GSDM - Geological Survey Department of Malawi, Zomba, Malawi
- GUC - Departamento de Geofisica, Universidad de Chile, Santiago
- GUV - CVG Electrificacion del Caroni (EDELCA) Guri, Venezuela
- HACU - Hacettepe University, Ankara, Turkey
- HDC - Universidad Nacional, Campus Omar Dengo, Heredia, Costa Rica
- HEL - Seismologian Laitos, Helsingin Yliopisto, Helsinki, Finland
- HFS - The Swedish Defence Research Agency, FOI, Stockholm, Sweden
- HIG - Hawaii Institute of Geophysics, Honolulu, USA
- HKC - Hong Kong Observatory, Kowloon, Hong Kong, China
- HKT - University of Texas Marine Science Institute, Galveston, USA (now ATX)
- HLW - National Research Inst. of Astronomy and Geophysics, Helwan, Egypt
- HNR - Ministry of Natural Resources, Honiara, Solomon Islands
- HON - NOAA, Pacific Tsunami Warning Center, Honolulu, Hawaii
- HRS - Earthquake and Volcano Observatory, Hirosaki University, Japan
- HRV - Harvard University, Cambridge, Massachusetts
- HSS - Inst. of Seismology and Volcanology, Hokkaido Univ., Sapporo, Japan
- HV - Hawaii Volcano Observatory
- HVO - USGS Hawaiian Volcano Observatory, Hawaii, USA
- HYB - National Geophysical Research Institute, Hyderabad, India
- ICE - Instituto Costariccense de Electricidad, San Jose, Costa Rica
- IDC - Internation Data Center
- IGIL - Inst. Geofisico do Infante D. Luis, Univ. de Lisboa, Lisbon, Portugal
- IIM - Instituto de Ingenieria, UNAM, Mexico City, Mexico
- INDR - Inst. Nac. de Recursos Hidraulicos, Santo Domingo, Dominican Rep.
- INEL - Idaho Nat. Engineering and Environmental Laboratory, Idaho Falls, USA
- INET - Instituto Nicaraguense de Estudios Territoriales, Managua, Nicaragua
- INMG - Instituto de Meteorologia, Lisbon, Portugal
- INPP - Ignalina Nuclear Power Plant, Ignalina, Lithuania
- INTV - INTEVEP, Caracas, Venezuela
- INY - Cornell University, Ithaca, New York, USA
- IPEC - Ustav fyziky Zeme, Masaryk University, Brno, Czech Republic
- IRSA - Institutul Roman de Seismologie Aplicata, Bucharest, Romania
- ISC - International Seismological Centre, UK
- ISCGEM - ISC-GEM
- ISK - Kandilli Observatory & Earthquake Research Inst., Istanbul, Turkey
- ISMP - USGS Induced Seismicity Project
- IST - Istanbul Technical University, Maslak, Istanbul, Turkey
- ISTP - Instituto Superior Tecnico, Lisbon, Portugal
- JCK - Geologisches Landesamt Nordrhein-Westfalen, Krefeld, Germany
- JEN - Inst. fuer Geowissenschaften, Friedrich-Schiller-Univ., Jena, Germany
- JHI - Regional Research Laboratory, Jorhat, India
- JMA - Japan Meteorological Agency, Tokyo, Japan
- JRQ - Centro de Geociencias, UNAM, Queretaro, Mexico
- JSN - University of the West Indies, Mona, Jamaica
- JSO - Jordan Seismological Observatory, Amman
- KAZK - Seismological Institute, Kazakhstan Academy of Sciences, Almaty
- KBC - Institut de Recherches Geologiques et Minieres, Ekona, Cameroon
- KGS - Kansas Geological Survey, University of Kansas, Lawrence, USA
- KISR - Kuwait Institute for Scientific Research, Safat, Kuwait
- KLM - Malaysian Meteorological Department, Petaling Jaya, Selangor, Malaysia
- KNET - Kyrgyz Broadband Seismic Network, La Jolla, Calif. and Kyrgyzstan
- KORS - GSRAS, Kola Regional Seismological Center, Apatity, Russia
- KOWA - Ecole Nationale d'Ingenieurs, Departement de Geologie, Bamako, Mali
- KRSC - GSRAS, Kamchatka Regional Seismo. Center, Petropavlovsk, Russia
- KRW - Geophysikalisches Institut, Karlsruhe, Germany
- KRYM - Crimean Geophysical Institute, Ukraine Academy of Science, Ukraine
- KUK - Ghana Geological Survey Department, Accra, Ghana
- KYRG - Institute of Seismology, Kyrgyzstan Academy of Sciences, Bishkek
- KYT - Faculty of Science, Kyoto University, Japan
- LASA - Large Aperture Seismic Array, Billings, Montana (closed)
- LBTB - Geological Survey of Botswana, Lobatse, Botswana
- LD - Lamont-Doherty Cooperative Seismographic Network
- LDG - CEA Lab. de Detection et de Geophysique, Bruyeres-le-Chatel, France
- LDN - University of Western Ontario, London, Ontario, Canada
- LDSN - Libyan Center for Remote Sensing and Space Science, Tripoli, Libya
- LEI - Institut fuer Geophysik und Geologie, Universitaet Leipzig, Germany
- LGS - Lithuanian Geological Survey, Vilnius, Lithuania
- LIC - Station Geophysique de Lamto, N'Douci, Cote d'Ivoire
- LIM - Instituto Geofisico del Peru, Lima, Peru
- LJC - Inst. of Geop. and Planet. Phys., UC San Diego, La Jolla, Calif, USA
- LJU - ARSO, Urad za seizmologijo, Ljubljana, Slovenia
- LLI - Instituto Internazionale di Vulcanologia--CNR, Catania, Italy
- LMM - Servico Meteorologico de Mocambique, Maputo, Mozambique (closed)
- LOA - Los Alamos Scientific Laboratories, Los Alamos, New Mexico, USA
- LPA - Observatorio Astronomico, Univ. Nacional de La Plata, Argentina
- LPZ - Observatorio San Calixto, La Paz, Bolivia
- LSZ - Geological Survey Department, Lusaka, Zambia
- LUB - Texas Tech University, Lubbock, USA
- LVM - Lawrence Livermore National Laboratory, Livermore, California, USA
- LVV - Carpathian Seismo. Dept., Ukraine Academy of Science, Lviv, Ukraine
- LWI - Departement de Geophysique, Lwiro, Democratic Republic of the Congo
- MACRO - Macroseismic location
- MB - Montana Bureau of Mines and Geology
- MBO - Institut de Recherche pour le Developpement, M'Bour, Senegal
- MDD - Instituto Geografico Nacional, Madrid, Spain
- MEL - Seismology Research Centre, Melbourne, Australia
- MERI - Maharashtra Engineering Research Institute, Nashik, India
- MES - Instituto Geofisico e Geodetico, Messina, Italy
- MHI - Seismological Observatory, Mashhad, Iran
- MNLO - USGS National Center for Earthquake Research, Menlo Park, Calif, USA
- MNM - University of Minnesota, Minneapolis, USA
- MOLD - Institute of Geophysics and Geology, Chisinau, Moldova
- MRB - Institut Cartografic de Catalunya (ICC), Barcelona, Spain
- MSCO - Mesa State College, Grand Junction, Colorado, USA
- MSKU - Universite des Sciences et Techniques de Masuku, Franceville, Gabon
- MSO - University of Montana, Missoula, USA
- MTAT - Mineral Research and Exploration Institute (MTA), Ankara, Turkey
- MUI - Geophysics Department, Ferdowsi University, Mashhad, Iran
- MVOV - Montserrat Volcano Observatory, Mango Hill, Montserrat
- NAI - Geology Department, University of Nairobi, Nairobi, Kenya
- NAO - NTNF/NORSAR, Kjeller, Norway
- NARS - NARS network, University of Utrecht, The Netherlands
- NASC - National Antarctic Scientific Center of Ukraine, Kiev, Ukraine
- NAT - Departamento de Fisica Teorica e Experimental, UFRN, Natal, Brazil
- NC - California Integrated Seismic Network: Northern California Seismic System (UC Berkeley, USGS Menlo Park, and Partners)
- NDI - India Meteorological Department, New Delhi
- NE - New England Seismic Network
- NED - Delaware Geological Survey, Newark
- NERS - GSRAS, Northeastern Regional Seismological Center, Magadan, Russia
- NGY - RCSVDM, Graduate School of Environmental Studies, Nagoya Univ., Japan
- NIC - Geological Survey Department, Nicosia, Cyprus
- NIED - Nat. Res. Inst. for Earth Sci. and Disaster Prevention, Tsukuba, Japan
- NIPR - National Institute of Polar Research, Tokyo, Japan
- NM - New Madrid Seismic Network
- NN - Nevada Seismological Laboratory
- NNC - Nat. Nuclear Center, Inst. of Geophysical Research, Almaty, Kazakhstan
- NOU - Institut de Recherche pour le Developpement, Noumea, New Caledonia
- NSAU - National Space Agency of Ukraine, Kiev, Ukraine
- NSSC - National Syrian Seismological Center, Damascus
- NSSP - National Survey of Seismic Protection, Yerevan, Armenia
- OBM - Mongolian Academy of Sciences, Ulaanbaatar
- OBN - GSRAS, Russian National Seismological Center, Obninsk, Russia
- OGSO - OhioSeis Network, Ohio Geological Survey, Columbus
- OK - Oklahoma Geological Survey Statewide Network, Norman, USA (aka TUL, OGS)
- OMAN - Department of Earth Sciences, Sultan Qaboos University, Al-Khod, Oman
- OMPT - Observatoire Midi-Pyrenees, Toulouse, France
- OTT - Geological Survey of Canada, Ottawa, Canada
- OUL - Sodankylan Geofysiikan Observatorio, Oulun Yliopisto, Oulu, Finland
- OVO - Osservatorio Vesuviano, Naples, Italy
- PAL - Lamont-Doherty Earth Observatory, Palisades, New York. USA
- PAR - Institut de Physique du Globe, Univ. P et M Curie, Paris, France
- PDA - Instituto de Meteorologia, Obs. Afonso Chaves, Ponta Delgada, Azores
- PDG - Seizmoloski zavod Crne Gore, Podgorica, Montenegro
- PEPP - Princeton Earth Physics Project, Princeton, New Jersey, USA
- PGC - Geological Survey of Canada, Pacific Geoscience Centre, Sidney, BC
- PGEC - Pacific Gas and Electric, California, USA
- PINS - Pakistan Inst. of Nuclear Science and Technology, Rawalpindi, Pakistan
- PIVS - Philippine Inst. of Volcanology & Seismology, Quezon City, Philippines
- PLV - Inst. of Geophysics, Vietnamese Acad. of Science and Technology, Hanoi
- PMG - Geological Survey, Port Moresby, Papua New Guinea
- PMR - National Tsunami Warning Center, Palmer, Alaska, USA
- PNNL - Pacific Northwest National Laboratory, Richland, Washington, USA
- POLR - POLARIS Project, Ottawa, Canada
- PPT - Laboratoire de Geophysique, Papeete, French Polynesia
- PR - Puerto Rico Seismic Network
- PRE - Council for Geoscience, Pretoria, South Africa
- PRO - Osservatorio Valerio, Pesaro, Italy
- PRT - Osservatorio San Domenico, Prato, Italy
- PT - Pacific Tsunami Warning Center (aka PTWC)
- PTN - State University of New York, Potsdam, New York, USA
- PTO - Porto (Serro do Pilar), Portugal
- QCP - Manila Observatory, Ateneo de Manila Univ., Manila, Philippines
- QDM - Queensland Department of Mines, Brisbane, Australia
- QMB - University of Leeds, Yorkshire, UK
- QUE - Pakistan Meteorological Department, Quetta, Pakistan
- QUI - Escuela Politecnica Nacional, Quito, Ecuador
- RAB - Geological Survey, Vulcano Observatory, Rabaul, Papua New Guinea
- RDJ - Observatorio Nacional, Rio de Janeiro, Brazil
- REN - University of Nevada, Reno, USA
- REX - Brigham Young University - Idaho, Rexburg, Idaho, USA
- REY - Veourstofa Islands, Reykjavik, Iceland
- RIPT - Research Inst. of Pulse Technique, Ministry for Atomic Energy, Russia
- RLP - Landeserdbebendienst Rheinland-Pfalz, Mainz, Germany
- RMOD - Russian Ministry of Defense, Russia
- ROM - Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy
- RSNC - Red Sismica Nacional de Colombia, INGEOMINAS, Bogota, Colombia
- RSPR - Red Sismica de Puerto Rico, Universidad de Puerto Rico, Mayaguez
- RUVS - Rede Universitaria de Vigilancia Sismovulcanica, Sao Miguel, Azores
- RYD - King Saud University, Riyadh, Saudi Arabia
- SAKL - Sakhalin Complex Research Institute, Novoalexandrovsk -- now SKHL net
- SAND - Sandia Laboratories, Albuquerque, New Mexico, USA
- SAPN - Emergency Management Office, Saipan, Northern Mariana Islands
- SBS - Institut National de la Meteorologie, Tunis, Tunisia
- SCP - Pennsylvania State University, State College, USA
- SDD - Universidad Autonoma de Santo Domingo, Dominican Republic
- SE - Center for Earthquake Research and Information
- SEA - Geophysics Program, University of Washington, Seattle, USA
- SEO - Korean Meteorological Administration, Seoul, South Korea
- SFS - Real Instituto y Observatorio de la Armada, San Fernando, Spain
- SHV - Inst. of Seismology and Volcanology, Kyushu Univ., Shimabara, Japan
- SJA - Instituto Nacional de Prevencion Sismica, San Juan, Argentina
- SKHL - GSRAS, Sakhalin Regional Seismological Ctr., Yuzhno-Sakhalinsk, Russia
- SKO - Seismological Observatory, Skopje University, Macedonia
- SLC - University of Utah, Salt Lake City, USA
- SLCI - University of Utah Research Institute, Salt Lake City, USA
- SLM - St. Louis University, St. Louis, Missouri, USA
- SNET - Servicio Nac. de Estudios Territoriales, San Salvador, El Salvador
- SNM - New Mexico Institute of Mining and Technology, Socorro, USA
- SNSN - Saudi NSN, King Abdulaziz City for Sci & Tech, Riyadh, Saudi Arabia
- SOF - Section of Seismology, Bulgarian Academy of Sciences, Sofia, Bulgaria
- SORS - Republic Hydrometeorological Inst., Banja Luka, Bosnia-Herzegovina
- SPEC - Special NEIS solution
- SPGM - Service de Physique du Globe, Rabat Agdal, Morocco
- SRPD - Savannah River Laboratory, Aiken, South Carolina
- SSNC - Centro Nacional de Investigaciones Sismologicas, Santiago de Cuba, Cuba
- SSO - Osservatorio Geofisico Sperimentale, Macerata, Italy
- STR - Ecole et Observatoire des Sciences de la Terre, Strasbourg, France
- STU - Institut fuer Geophysik der Universitaet Stuttgart, Stuttgart, Germany
- SVA - Department of Mineral Resources, Suva, Fiji
- SVSA - Sistema de Vigilancia Sismologica dos Acores, Ponta Delgada, Azores
- TAJK - Tajikistan Academy of Sciences, Dushanbe, Tajikistan
- TAN - Institut et Observatoire Geophysique d'Antananarivo, Madagascar
- TAP - Central Weather Bureau, Taipei, Taiwan
- TATO - Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan
- TAU - University of Tasmania, Hobart, Australia
- TBU - Environmental Physics Institute, Tibet University, Lhasa, China
- TEH - Institute of Geophysics, University of Tehran, Iran
- THE - Geophysical Laboratory, University of Thessaloniki, Greece
- THR - Intl. Inst. of Earthquake Engineering and Seismology, Tehran, Iran
- TIF - Institute of Geophysics, Academy of Sciences of Georgia, Tbilisi, Georgia
- TIR - Seismological Center, Academy of Sciences of Albania, Tirana
- TOH - AOB, Graduate School of Science, Tohoku University, Sendai, Japan
- TOL - Observatorio Geofisico de Toledo, Spain (MDD network)
- TRI - Ist. Nazle. di Oceanografia e di Geof. Sperimentale, Trieste, Italy
- TRKM - Institute of Seismology, Turkmenistan Academy of Science, Ashgabat
- TRN - University of the West Indies, St. Augustine, Trinidad
- TVA - Tennessee Valley Authority, Knoxville, Tennessee
- TX - Texas Seismological Network (TexNet) (aka TEXNET, BEG)
- TZN - University of Dar es Salaam, Tanzania
- UAV - Laboratorio de Geofisica, Universidad de los Andes, Merida, Venezuela
- UBC - University of British Columbia, Vancouver, B.C., Canada
- UBIC - Univ. de Barcelona i Institut d'Estudis Catalans, Barcelona, Spain
- UCC - Observatoire Royal de Belgique, Uccle, Brussels, Belgium
- UCR - Seccion de Sismologia, Univ. de Costa Rica, San Jose, Costa Rica
- UDEC - Universidad de Concepcion, Concepcion, Chile
- UDO - Centro de Sismologia, Universidad de Oriente, Cumana, Venezuela
- UNAH - Universidad Nacional Autonoma de Honduras, Tegucigalpa, Honduras
- UNM - Instituto de Geofisica, UNAM, Mexico City, DF, Mexico
- UPA - Instituto de Geociencias, Universidad de Panama, Panama
- UPP - Department of Earth Sciences, Uppsala University, Uppsala, Sweden
- UPSL - University of Patras Seismological Laboratory, Patras, Greece
- URS - Kochi University, Kochi, Japan
- US - USGS National Earthquake Information Center, PDE (aka GS, NEIC)
- USAF - US Air Force Technical Applications Center, Melbourne, Florida, USA
- USAV - USGS Alaska Volcano Observatory, Anchorage, USA
- USBR - US Bureau of Reclamation, Denver, Colorado, USA
- USC - University of Southern California, Los Angeles, USA
- USCV - USGS Cascades Volcano Observatory, Vancouver WA, USA
- USGS - US Geological Survey--other than ABQ, AGS, MNLO, NEIC, HVO and USAVO
- UTSU - Utsunomiya University, Japan
- UU - University of Utah Seismograph Stations
- UVC - Universidad del Valle, Cali, Colombia
- UW - Pacific Northwest Seismic Network (aka PNSN)
- UZBK - Institute of Seismology, Uzbekistan Academy of Sciences, Tashkent
- VAO - Inst. de Astron., Geof. e Ciencias Atmos., Univ. de Sao Paulo, Brazil
- WAR - Instytutu Geofizyki, Polskiej Akademii Nauk, Warsaw, Poland
- WEL - Inst. of Geological and Nuclear Sciences, Lower Hutt, New Zealand
- WES - Weston Observatory, Boston College, Weston, Massachusetts, USA
- WIEN - Inst. fuer Meteorologie und Geophysik, Univ. Wien, Vienna, Austria
- WIHG - Wadia Institute of Himalayan Geology, Dehra Dun, India
- WWC - Woodward-Clyde Consultants, California
- YARS - GSRAS Siberian Branch, Yakutiya Reg. Seis. Center, Yakutsk, Russia
- ZAG - Geophysical Institute, University of Zagreb, Croatia
- ZAMG - ZentralAnstalt fuer Meteorologie und Geodynamik, Vienna, Austria
- ZON - Universidad Nacional de San Juan, San Juan, Argentina
- ZUR - Schweizerischer Erdbebendienst, Zurich, Switzerland