29 July 2025 M8.8 Kamchatka earthquake and tsunami: Post-Event Assessment Questionnaire

An earthquake at a depth of 35km with a magnitude of 8.8 (USGS) on 29 July 2025 23:24 (UTC) offshore Kamchatka, Russia resulted in a TSUNAMI THREAT MESSAGE issued by the Pacific Tsunami Warning Center (PTWC), Tsunami Service Provider (TSP) of the Intergovernmental Coordination Group for the Pacific Tsunami Warning and Mitigation System (ICG/PTWS), 10 min after the event indicating the possibility of hazardous tsunami waves (based on magnitude 8.0 and depth of 74 km) for coasts located in Russia and Japan within 300 km of the earthquake epicenter.

The Working Group on Tsunami and other Hazards related to Sea-Level Warning and Mitigation Systems (TOWS-WG) on Tsunami Watch Operations, jointly with the Task Team on Disaster Management and Preparedness recommended that the trigger for implementing a post-event assessment should be a tsunami threat of >1 m amplitude forecast in one or more countries in a region. Over and above this trigger level, the final decision to implement a survey should be decided by the regional Tsunami Information Centre (TIC) in consultation with the ICG Steering Group and the ICG Secretariat taking into consideration whether the tsunami resulted in a national response in one or more countries.

From the forecast polygons issued for this event and the sea-level observations as reported in the final message of the PTWC, the trigger threshold was reached. Following consultations with the International Tsunami Information Center (ITIC) and the PTWS Steering Committee it has been agreed that the recent event provides us with an opportunity to evaluate the performance of the system. It will enable Member States of the ICG/PTWS to identify those components which worked properly and, most importantly, any components which did not work in an appropriate manner and are in need of further attention.

To evaluate the performance of the PTWS and to provide a benchmark of the present status of the system we seek your support and cooperation to complete this questionnaire as fully and accurately as possible. This may involve obtaining inputs from different organisations, but we believe that this effort will have direct benefits for the entire Pacific community at regional, national and local levels.

IOC Circular Letter 3052 (8 August 2025) announced the assessment and attached the post-event assessment questionnaire, which was designed and approved by the TOWS-WG and subsequently accepted by the IOC Assembly at its 28th session, 18–25 June 2015.

Please complete and return the Kamchatka PEA questionnaire through this online survey. The questionnaire can also be filled out offline (fillable PDF file) and submitted by email to laura.kong@noaa.gov copied to o.necmioglu@unesco.org. The deadline for returning the questionnaire is 5th September 2025.

After receiving the questionnaires from the Member States, the information will be compiled and published in a report, which will be distributed to ICG/PTWS members.

We would like to stress that the objective of this assessment is to be positive and constructive, and not to be in any way critical or judgemental. We would like the report to be as open and honest as possible, and we hope that you will approach the questionnaire in this spirit. We would also welcome any other information you would like to be included in the report, such as photographs, national reports of the event or any comments on the system and areas in need of improvement.

We are confident that all Member States will understand the importance and value of conducting this assessment and we rely on your support. It is vital that we use such events to measure the performance of the PTWS in order to test it and improve it for future tsunami events with even higher destructive potential.