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The responsibility for Puerto Rico and the U.S. Virgin
Islands was passed to the West Coast/Alaska Tsunami Warning Center in June 2007, while PTWC continued to issue advice for other parts of the Caribbean Sea. In 2013, the West Coast/Alaska Tsunami Warning Center became known as the National Tsunami
142:
The expanded system became operational in April 1965 but, like its local predecessor, was limited to teletsunamis - tsunamis which are capable of causing damage far away from their source. The system covered all countries of the
Pacific Ocean with data from 20 seismic stations around the world and 40
559:
Official tsunami warnings and watches are limited to U.S. coastlines, with the exception of the
British Virgin Islands. PTWC messages for other regions do not include alerts, but rather advice, as the authority to issue tsunami warnings was delegated to member states in 2014 to avoid confusion among
84:
PTWC is also the operational center of the
Pacific Tsunami Warning System and issued tsunami warnings for dozens of countries from 1965 to 2014. In October 2014, the authority to issue tsunami warnings was delegated to individual member states. As a result, the center now issues advice rather than
198:
In
October 2014, the authority to issue official tsunami warnings for coastlines in the Pacific was delegated to individual member states. This happened because warnings and watches issued by PTWC caused confusion when they conflicted with a country's independently derived level of alert. As a
168:
in Canada, but only for earthquakes in the vicinity of the West Coast. PTWC continued to provide coverage of teletsunamis. The Alaska center's responsibilities were expanded in 1996 to include all
Pacific-wide sources, after which it became known as the West Coast/Alaska Tsunami Warning Center
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These stations give detailed information about tsunamis while they are still far off shore. Each station consists of a sea-bed bottom pressure recorder (at a depth of 1000–6000 m) which detects the passage of a tsunami and transmits the data to a surface
172:
On
December 1, 2001, the PTWC was re-dedicated as the Richard H. Hagemeyer Pacific Tsunami Warning Center, in honor of the former U.S. Tsunami Program Manager and National Weather Service Pacific Region Director who managed the center for many years.
180:, the Pacific Tsunami Warning Center's responsibilities were expanded to include tsunami guidance for the Indian Ocean, the South China Sea and the Caribbean Sea, though its authority to issue warnings was limited to
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system. The bottom pressure recorder lasts for two years while the surface buoy is replaced every year. The system has considerably improved the forecasting and warning of tsunamis in the
Pacific Ocean.
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In April 2017, the responsibility for Puerto Rico and the U.S. Virgin
Islands returned to PTWC, along with the British Virgin Islands, to consolidate Caribbean responsibilities under one warning center.
209:
As of 2023, the
Pacific Tsunami Warning System has access to about 600 high-quality seismic stations around the world and about 500 coastal and deep-ocean sea level stations. It has 46 member states:
150:, which killed 131 people, it was decided to create another warning system to provide timely warnings about local events for coastal areas of Alaska. After Congress approved funding in 1965, the
112:, a plan was devised to warn the public of possible tsunami inundation. The facility became operational in 1948 and was called the Seismic Sea Wave Warning System (SSWWS), headquartered at the
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or email alerts from the PTWC web site, and the UNESCO site. Email and text messages are also available from the USGS Earthquake Notification Service which includes tsunami alerts.
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161:, which killed several people, highlighted the threat of tsunamis caused by nearby events. As a result, PTWC began issuing tsunami warnings for local events near Hawaii.
139:, with the Seismic Sea Wave Warning System as its operational center. As a result, the name of the facility was changed to the Pacific Tsunami Warning Center.
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result, the center now issues advice rather than official warnings for all non-U.S. coastlines, with the exception of the British Virgin Islands.
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PTWC discontinued its messages for the Indian Ocean in 2013 after regional tsunami warning centers were opened in Australia, India and Indonesia.
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gauges in the area of the earthquake are checked to establish if a tsunami has formed. The center then forecasts the future of the tsunami.
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In 1982, the Alaska Tsunami Warning Center's area of responsibility was enlarged to include California, Oregon and Washington, as well as
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Local populations in the United States of America receive tsunami information through radio and television receivers connected to the
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In 2015, the annual operating cost of the Pacific Tsunami Warning System was estimated to be between 50 and 80 million U.S. dollars.
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135:, which killed thousands of people, led to the establishment of the Pacific Tsunami Warning System under the auspices of UNESCO's
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was launched in September 1967 with observatories in Palmer, Adak and Sitka. At that time, PTWC ended its coverage of Alaska.
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1049:"User's guide for the Pacific Tsunami Warning Center: enhanced products for the Pacific Tsunami Warning System"
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Up until the late 1940s, the United States had no way to warn the public about tsunami threats. After the
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New Tsunami.gov Website Represents Major Advance in Tsunami Warning Center Product Dissemination
188:. For all other areas, the decision to issue tsunami warnings was left to individual countries.
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Earthquake notification. In some cases it may caution about the possibility of a local tsunami
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Earthquake notification. In some cases it may caution about the possibility of a local tsunami
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Earthquake notification. In some cases it may caution about the possibility of a local tsunami
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official warnings for non-U.S. coastlines, with the exception of the British Virgin Islands.
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One of two tsunami warning centers that are operated by NOAA, located on Ford Island, Hawaii
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and roving loudspeaker broadcasts from police vehicles. The public can subscribe to the
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Please help update this article to reflect recent events or newly available information.
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via acoustic modem. The surface buoy then radios the information to the PTWC via the
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Widespread, dangerous coastal flooding accompanied by powerful currents are possible
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Widespread, dangerous coastal flooding accompanied by powerful currents are possible
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The PTWC uses seismic data as its starting point, but then takes into account
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131:(distant events), using data from 4 seismic stations and 9 tide gages. The
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915:(DART) system. By 2001, an array of six stations had been deployed in the
169:(WCATWC). As a result, PTWC's area of responsibility was further reduced.
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in the Caribbean Sea. Other parts of the United States are covered by the
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In some regions, tsunami sirens are used to help alert the public
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Initially, the Seismic Sea Wave Warning System covered only the
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Beginning in 2005, as a result of the tsunami caused by the
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The alert levels below were retired on October 1, 2014.
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Seismological observatories, organisations and projects
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currents dangerous to those in or very near the water
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Dangerous coastal flooding and/or strong and unusual
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Stay tuned for more information, be prepared to act
772:An event may impact the watch area at a later time
726:An event may impact the watch area at a later time
609:Stay out of water, away from beaches and waterways
595:Dangerous coastal flooding and powerful currents
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913:Deep-ocean Assessment and Reporting of Tsunamis
903:Deep-ocean Assessment and Reporting of Tsunamis
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639:International Tsunami Messages (2014–present)
987:"50 years of tsunami warning in the Pacific"
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548:Indian Ocean (2005–2013), South China Sea
137:Intergovernmental Oceanographic Commission
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178:2004 Indian Ocean earthquake and tsunami
92:data when calculating possible threats.
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1299:How the US Tsunami Warning System works
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1324:Earthquake and seismic risk mitigation
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1223:Historical DART Background Information
1156:: CS1 maint: archived copy as title (
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877:, and in some places (such as Hawaii)
780:Strong currents or waves are possible
152:Alaska Regional Tsunami Warning System
897:A diagram of the DART II system
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570:U.S. Tsunami Messages (2014–present)
133:1960 Valdivia earthquake and tsunami
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1289:Northwest Pacific Tsunami Advisory
796:Indian Ocean and the Caribbean Sea
159:1975 Hawaii earthquake and tsunami
148:1964 Alaska earthquake and tsunami
14:
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1198:"Earthquake Notification Service"
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176:In 2005, in the aftermath of the
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1021:"Tsunami Warning Center History"
963:"Tsunami - Technical Memorandum"
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237:(which is considered to include
116:'s seismological observatory in
106:1946 Aleutian Islands earthquake
1339:Emergency management in Oceania
1284:National Tsunami Warning Center
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79:National Tsunami Warning Center
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696:Pacific Ocean excluding Hawaii
631:No action needed at this time
598:Move to high ground or inland
411:Federated States of Micronesia
31:Pacific Tsunami Warning Center
1:
1344:1949 establishments in Hawaii
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818:Destructive tsunami possible
924:2004 Indian Ocean earthquake
889:Deep-ocean tsunami detection
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1098:PTWC Messages Pacific Ocean
1087:Tsunami Message Definitions
65:in the Pacific, as well as
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1120:PTWC Messages Indian Ocean
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496:Tsunami warning authority
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1279:US Tsunami Warning System
850:This section needs to be
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114:Coast and Geodetic Survey
687:Old format (before 2014)
512:Northern Mariana Islands
339:Northern Mariana Islands
146:In the aftermath of the
63:Northern Mariana Islands
533:All other parts of the
49:warning centers in the
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875:Emergency Alert System
524:British Virgin Islands
477:
343:Minor Outlying Islands
231:Juan Fernández Islands
75:British Virgin Islands
26:
1034:PTWC Responsibilities
1000:PTWC Responsibilities
911:began developing the
901:Further information:
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1109:PTWC Messages Hawaii
879:civil defense sirens
677:Minor waves at most
1178:on October 16, 2009
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520:U.S. Virgin Islands
186:U.S. Virgin Islands
127:and was limited to
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267:Galapagos Islands
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1174:. Archived from
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399:Marshall Islands
371:French Polynesia
192:Warning Center.
166:British Columbia
125:Hawaiian Islands
45:, is one of two
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403:Kwajalein Atoll
391:Phoenix Islands
387:Gilbert Islands
385:(including the
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143:tide stations.
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862:August 2023
516:Puerto Rico
419:New Zealand
401:(including
369:(including
353:(including
333:(including
315:South Korea
311:Philippines
271:El Salvador
259:North Korea
225:(including
182:Puerto Rico
67:Puerto Rico
39:Ford Island
1308:Categories
946:References
395:Kiritimati
341:, and the
255:East Timor
251:Costa Rica
120:, Hawaii.
939:satellite
907:In 1995,
777:Advisory
603:Advisory
351:Australia
323:Singapore
299:Nicaragua
283:Indonesia
275:Guatemala
239:Hong Kong
1152:cite web
883:RSS feed
761:Warning
715:Warning
592:Warning
537:and the
491:Regions
383:Kiribati
327:Thailand
291:Malaysia
279:Honduras
247:Colombia
229:and the
215:Cambodia
184:and the
118:Honolulu
73:and the
61:and the
1319:Tsunami
1208:June 4,
1182:June 4,
1142:June 4,
852:updated
661:Threat
488:Status
467:Vanuatu
465:), and
447:Tokelau
409:), the
397:), the
347:Vietnam
263:Ecuador
100:History
47:tsunami
815:Watch
769:Watch
742:Hawaii
723:Watch
614:Watch
500:Hawaii
457:, the
455:Tuvalu
441:, the
407:Majuro
389:, the
367:France
319:Russia
303:Panama
295:Mexico
219:Canada
211:Brunei
110:Hawaii
69:, the
43:Hawaii
966:(PDF)
451:Tonga
439:Samoa
431:Palau
415:Nauru
287:Japan
243:Macau
235:China
223:Chile
1294:DART
1210:2011
1184:2011
1158:link
1144:2011
936:GOES
932:buoy
909:NOAA
508:Guam
427:Niue
405:and
393:and
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