Intergovernmental Oceanographic Commission (IOC-UNESCO) was mandated by the United Nations to establish global tsunami warning systems across different ocean basins. This led to the creation of four regional warning and mitigation systems: the Pacific Tsunami Warning and Mitigation System (PTWS), the Indian Ocean Tsunami Warning and Mitigation System (IOTWMS), the North-eastern Atlantic, Mediterranean and Connected Seas Tsunami Warning System (NEAMTWS), and the Caribbean and Adjacent Regions Early Warning System (CARIBE-EWS), each overseen by an Intergovernmental Coordination Group (ICG).

While tsunami warning systems continue to save numerous lives, the 2018 Palu and Anak Krakatoa, and 2022 Hunga Tonga - Hunga Ha’apai events illustrated the challenges of current Tsunami Warning Systems locally and globally. These events are catalogued as “non-seismic and complex source tsunamis” which make up 13% of the world’s confirmed tsunamis. Such tsunamis are not caused by subduction zone earthquakes and thus pose a challenge to current tsunami warning protocols.

To address such challenges, IOC-UNESCO launched the UN Ocean Decade Tsunami Programme with an aim to (i) develop warning systems capability to issue actionable and timely tsunami warnings for tsunamis from all sources and (ii) 100% of communities at risk be prepared and resilient to tsunamis by 2023 through programs such as the TRRP. Considering the IOC Technical Series 183 on “Monitoring and Warning for Tsunamis Generated by Volcanoes” an important first step towards addressing non seismic tsunamis, the 57^th Session of the IOC Executive Council, requested the IOC Secretariat to: (i) Distribute the report to Volcano Observatories and UNESCO-IOC Member States; and (ii) Organise online webinars for each of the Intergovernmental Coordinating Groups (ICG) of regional Tsunami warning Systems involving relevant Volcano Observatories and Volcanic Ash Advisory Centres (VAACs).

Following this recommendation, two global online webinars are being organised by the UNESCO-IOC on 16 and 23 April 2025 at different time slots to facilitate participation by people in different time zones.

• 16 April, 09:00-10:30 UTC
• 23 April, 20:00-21:30 UTC

The objectives of the global webinars are to:

1. Brief on the report on ‘Monitoring and warning for tsunamis generated by volcanoes’ (IOC/2024/TS/183) and its recommendations
2. Highlight the hazard and vulnerable Member States
3. Initiate the required partnerships between National Tsunami Warning Centres (NTWC) and Volcano Observatories and VAACs
4. Initiate consideration of whether Tsunami Service Providers may also need to provide services where tsunami generated by volcanoes may impact several Member States

Invitees and participants of the global webinars include:

• UNESCO-IOC
• International Civil Aviation Organization (ICAO)
• ICG Tsunami National Contacts (TNCs)
• ICG Tsunami Warning Focal Points (TWFPs)
• ICG National Tsunami Warning Centres (NTWCs)
• ICG Tsunami Service Providers (TSPs)
• ICG National Disaster Management Offices (DMOs)
• ICG Expert Teams
• Regional Disaster Management organizations like CDEMA, CEPREDENAC, ASEAN DRR, SPC Geoph.
• Volcano Observatories (VO)
• Volcanic Ash Advisory Centres (VAACs)
• International Union of Geodesy and Geophysics (IUGG) Joint Tsunami Commission
• International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI)
• World Meteorological Organization (WMO)
• World Organization of Volcano Observatories (WOVO)
• Researchers and Experts
• Other relevant organisations and Experts