The two-day International Symposium will recognize the history, achievements, and primary challenges facing the Pacific Tsunami Warning and Mitigation System (PTWS); one of the IOC’s most successful international scientific programs with a direct humanitarian aim of mitigating the effects of natural disasters to save lives and property. The Symposium will bring together tsunami experts and key decision makers to review the current state of the PTWS and discuss practical and tangible next steps, desirable partnerships, and necessary commitments needed to sustain and evolve the System for the future. The Pacific Ocean basin is the largest and most tsunami-prone of any of the Earth’s ocean basins. Approximately 75% of the world’s known fatal tsunamis have been generated in the Pacific. Modern tsunami warning system development and coordination of the international tsunami warning efforts started in 1960 after the M9.5 Chile tsunami crossed the Pacific killing 61 people in Hawaii, 139 in Japan and at least 20 in the Philippines a day later. In 1965, culminating key meetings and discussions of scientists, policy-makers, and countries facilitated by UNESCO and its Intergovernmental Commission (IOC), International Union of Geodesy and Geophysics (IUGG), and the World Meteorological Organization (WMO), Member States of the IOC established the International Coordination Group for the Tsunami Warning System in the Pacific (ICG/ITSU), along with the International Tsunami Information Center (ITIC) and Pacific Tsunami Warning Center (PTWC). In 2005, the ICG/ITSU was renamed as the Intergovernmental Coordination Group for the Pacific Tsunami Warning and Mitigation System (ICG/PTWS). The ICG/PTWS, encompassing 46 countries of the Pacific Ocean and its marginal seas, has met biennially since 1968 to coordinate tsunami mitigation activities, including the issuance of timely international warning advice. Today, thanks to international coordination and data sharing, the System’s Tsunami Service Providers (US and Japan) are able to rapidly assess the tsunamigenic potential of great earthquakes and provide tsunami threat forecast information to nations within 5-10 minutes. Registration: The Symposium is open attendance with no registration fee. Registration is on a ‘first-in, first-served’ basis up to a limit of 150 participants. Fully completed registrations are due March 13, 2015. For Symposium Registration, Participant List, and Meeting Documents, visit http://www.ptws50.info