Click to download PTWS-XXIX Organizational Structure, Working Groups and Task Teams 2021-2023 (update May 2023)
Click to download PTWS 50th Book Book (PDF, 10.6 MB) (Apr 2015)
Click to download PTWS Brochure (PDF, 356 KB) (Apr 2019)
Click to download PTWS Information Sheet (PDF, 132 KB) (Dec 2022)
Click to view PTWS Tsunami Warning! video (Apr 2015)
Existing Services of the Global Tsunami Warning System
(Intergovernmental Oceanographic Commission of UNESCO, Feb 2020)
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The Intergovernmental Coordination Group for the Pacific Tsunami Warning and Mitigation System (ICG/PTWS, formerly known as ICG/ITSU for International Tsunami) is coordinated by UNESCO's Intergovernmental Oceanographic Commission (IOC). It was established in 1965 as the ICG/ITSU for International Tsunami, and first convened in 1968. An international cooperative effort involving Member States of the Pacific, the ICG/PTWS meets regularly to review progress and coordinate activities resulting in improvements of the service. The PTWS encompassess 46 countries of the Pacific Ocean and its marginal seas. It is one of the most successful international scientific programmes with the direct humanitarian aim of mitigating the effects of tsunami to save lives and property.
Globally over history, 90% of the casualties have been caused by local or regional tsunamis where waves attack in minutes to hours. As such, emphasis has been on building community-level resiliency through timely warnings to a prepared and knowledgeable public that recognizes a tsunami and knows what to do and where to go to save their life.
The PTWS area of responsibility includes the Pacific Ocean, the Southern Ocean regions of the Pacific and all attached marginal seas, including the Philippine Sea, East China Sea, Yellow Sea, Sea of Okhotsk, Bering Sea, South China Sea, Java Sea, Arafura Sea, Sulawesi Sea, Mindanao Sea, Sulu Sea, Celebes Sea, Bismarck Sea, Solomon Sea, Coral Sea, and Tasman Sea.
PTWS MEMBER STATES: 46 countries
Altogether, there are 46 Member States covering the Pacific and its marginal seas. Official Member States of the ICG/PTWS are those who are members of UNESCO and the IOC, and who have officially designated Tsunami National Contacts and Tsunami Warning Focal Points through formal channels. The following information is current through May 2015.
ICG/PTWS Member States with formal official designations (bold): 34
Member States that are not IOC Member States marked with *: 6
Member States with no recent information marked with +: 1
PACIFIC RIM MEMBER STATES (27):
Brunei Darusalaam *, Cambodia *, Canada, Chile – including Easter Island and Juan Fernandez Islands, China - mainland, Hong Kong, Macau, Colombia, Costa Rica, Democratic Republic of Timor-Lester (East Timor), Democratic Republic of Korea (North Korea) +, Ecuador – including Galapagos Islands, El Salvador, Guatemala, Honduras, Indonesia, Japan, Malaysia, Mexico, Nicaragua, Panama, Peru, Philippines, Republic of Korea (South Korea), Russian Federation, Singapore, Thailand, United States of America – including States, Territories of American Samoa and Guam, Commonwealth of Northern Mariana, Islands, and US Minor Outlying Islands (Baker, Howland, Jarvis, Johnston, Kingman Reef, Midway, Palmyra, Wake), Vietnam
PACIFIC ISLAND MEMBER STATES (19)
Australia – including Territory of Norfolk, Coral Sea, Cook Islands (free association New Zealand), Fiji, France, France – French Polynesia, New Caledonia, Wallis and Futuna, Kiribati – Gilbert, Phoenix, Christmas, Republic of Marshall Islands (free association USA) – Kwajalein, Majuro *, Micronesia,Federated States of (free association USA) * – Chuuk, Kosrae, Pohnpei, Yap, Nauru *, New Zealand – including Kermadec Islands, Niue (free association New Zealand), Palau (free association USA), Papua New Guinea, Samoa, Solomon Islands, Tokelau *, Tonga, Tuvalu, UK – Pitcairn, Vanuatu
INTERNATIONAL TSUNAMI INFORMATION CENTER (ITIC)
The IOC maintains the International Tsunami Information Centre (ITIC). Established in 1965 and staffed by the U.S.A. and Chile, the ITIC works closely with NOAA’s Richard H. Hagemeyer Pacific Tsunami Warning Center (PTWC), and other international tsunami centres such as Japan's Northwest Pacific Tsunami Advisory Center (NWPTAC), China's South China Sea Tsunami Advisory Center (SCSTAC), Nicaragua's Central America Tsunami Advisory Centre (CATAC, interim service since 2022), and NOAA's US National Tsunami Warning Center (US NTWC).
ITIC's primary responsibilities also include:
PACIFIC TSUNAMI WARNING CENTER (PTWC)
The PTWC serves as the operational warning headquarters for the Pacific Tsunami Warning and Mitigation System. PTWC works closely with other international, sub-regional and national centers in monitoring seismic and sea level stations around the Pacific Ocean for large earthquakes and tsunami waves. The PTWS makes use of about 600 high-quality seismic stations around the world to locate potentially tsunamigenic earthquakes, and accesses about 500 coastal and deep-ocean sea level stations globally to verify the generation and evaluate the severity of a tsunami. The system disseminates tsunami information and warning messages to designated national authorities in over 100 locations across the Pacific. Sub-regional centres such as the US NTWC, NWPTAC, and SCSTAC provide regional alerts to the U.S.A. west coast, Alaska and Canada, and the northwest Pacific and South China Sea regions, respectively.
For further information, contact ptws@unesco.org, itic@unesco.org