PTWS Brochure


The Intergovernmental Coordination Group for the Pacific Tsunami Warning and Mitigation System (ICG/PTWS) 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. 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. 


Download PTWS Brochure     PDF (381K) [March 2014]



PTWS Information Document


Download PTWS Information document  (countries and organizational structure)   PDF (48 KB)



WHAT: The ICG/PTWS is subsidiary body of the Intergovernmental Oceanographic Commission (IOC) of the United Nations Educational, Scientific, and Cultural Organization (UNESCO). The ICG/PTWS was renamed from the International Coordination Group for the Tsunami Warning System in the Pacific (ICG/ITSU) in 2005 to an intergovernmental body focusing on commitments of member states to continually embrace the comprehensive nature of tsunami risk reduction. For more information, visit the PTWS Website. For general information on tsunamis, visit or

WHO: The ICG/PTWS is comprised of IOC Member States bordering and within the Pacific Ocean and other interested Member States. The Pacific is comprised of 46 countries. Of these, 43 have identified Tsunami National Contacts and Tsunami Warning Focal Points for receiving information on international tsunami mitigation activities and tsunami alerts or advisories from the PTWC, JMA, and/or US NTWC that serve as the international tsunami alert centres for the PTWS.

HISTORY: The internationally-coordinated tsunami early warning system was established in 1965 in response to the 1960 M9.5 Chile earthquake which generated a Pacific-wide tsunami that travelled across the Pacific causing damage and deaths in Hawaii (59 deaths), Japan (139 deaths), and the Philippines (> 20 deaths). The goal of the warning system is to provide timely and reliable alerts. The system depends on the free and open sharing of seismic and sea level data to be able to continuously monitor and evaluate tsunamigenic events, and robust international communications systems for the timely dissemination of alerts to all countries. Over history, 74% of the world’s deadly tsunamis have occurred in the Pacific. In the last 10 years (since 2004), there have been 14 deadly tsunamis, with nine occurring in the Pacific. 

PURPOSE: The ICG/PTWS acts to coordinate international tsunami warnings and mitigation activities. One of the most important activities of the ICG/PTWS is ensure the timely issuance of tsunami alerts in the Pacific. The system, as described by the PTWS Operational Users Guide (Jan 2009, update 2011, formerly Communications Plan), depends on the free and open sharing of seismic and sea level data to continuously monitor and evaluate tsunamigenic events, and robust international communications systems for the timely dissemination of tsunami threat advice to each country’s National Tsunami Warning Centres (NTWC). The NTWC’s are then responsible for issuing tsunami warnings to their citizens, and they work with their national and local emergency management agencies to ensure public safety during emergencies. Comprehensive tsunami mitigation programmes require complementary and sustained activities in tsunami hazard risk assessment, tsunami warning and emergency response, and preparedness. Stakeholder involvement and coordination is essential, and community-based, people-centred mitigation activities will help to build tsunami resiliency. 

Read more: PTWS Information Document


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Featured Resources

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Regional Disaster Information Center (Latin America & the Caribbean)

A database of Spanish language materials focused on tsunami preparedness.
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Post-Tsunami Survey:
El Salvador Summary Video

Learn the basics of a post-tsunami survey.

TsunamiTeacher USA
Tsunami Basics

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Learn the basics of tsunamis. Available in English and Samoan.

Tsunamis on the Move

Tsunami Awareness Poster

Awareness poster available in English, Chinese, French, Japanese, Korean, Portuguese, Singalese.


Global Hazard Maps

Posters of Tsunami Sources, Significant Earthquakes and Significant Volcanic Eruptions. Also Tsunami Sources Icosohedron Globe.

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Tsunami, The Great Waves

Available in English, Spanish, French and Chinese.


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Tsunami Glossary

Available in English, Arabic, Spanish, French and Bahasa. 



Where the First Wave Arrives in Minutes

Available in English, Bahasa, Spanish and French.


DVD copies for PC and Macintosh computers are available free of charge from the ITIC, Hawaii (

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