A global tsunami response: Pacific tsunami alerts follow 29 July 2025 M8.8 Kamchatka earthquake

A powerful magnitude 8.8 earthquake struck off Russia’s Kamchatka Peninsula at 23:24 UTC on 29 July, triggering the activation of tsunami warning systems across the Pacific.

Following decades of cooperation under the Intergovernmental Oceanographic Commission (IOC) of UNESCO, millions of people were alerted within minutes, enabling immediate protective actions and helping prevent loss of life.

According to the United States Geological Survey (USGS), the earthquake occurred at a depth of 21 km, making it the most powerful seismic event globally since the 2011 Tōhoku earthquake in Japan, and one of the ten strongest recorded since 1900.

Rapid Alerts Across the Pacific

Ten minutes after the event, the Pacific Tsunami Warning Center (PTWC), a key component of the IOC coordinated Pacific Tsunami Warning and Mitigation System (ICG/PTWS), issued its initial Tsunami Threat Message for coastal regions in Russia and Japan.

National and Regional Responses

Russia and Japan

• Russia declared a state of emergency in the northern Kuril Islands after tsunami waves struck Severo-Kurilsk.
• Japan ordered the evacuation of approximately 1.9 million residents in affected coastal prefectures.
• Fukushima Daiichi and Daini nuclear plants were evacuated as a precaution; the International Atomic Energy Agency (IAEA) later confirmed no safety-related impacts.

North America

• California and British Columbia issued coastal advisories, urging residents to stay away from beaches and low-lying areas.

Latin America

• Chile declared a red alert for Pascua Island and coastal regions in the north and center of the country.
• Ecuador issued a tsunami advisory for the Galápagos Islands, suspended maritime activities, and evacuated coastal zones.
• Peru and Colombia activated precautionary alerts and implemented local safety measures.

Pacific Islands

• Hawaii recorded wave heights of up to 1.74 metres in Kahului (Maui).
• French Polynesia revised its expected wave forecasts to reach up to 4 metres in certain areas, but observed wave heights remained under 1m.
• Fiji, Tonga, the Cook Islands, and Samoa issued tsunami watches, which were later downgraded.

Asia-Pacific 

• Tsunami alerts were issued in China, the Philippines, Indonesia, New Zealand, Vietnam, and Malaysia.

By 07:24 UTC, confirmed tsunami waves had reached Hawaii, and tide gauges in Japan recorded wave heights up to 0.32 metres. Strong currents and other hazardous marine conditions persisted across affected areas, prompting continued caution even after major warnings were lifted.

Aftershocks and Volcanic Activity 

The main event was followed by 24 aftershocks exceeding magnitude 5.0, including a M6.9 tremor, according to USGS, and followed by an eruption at Klyuchevskoy volcano in Kamchatka. Located along the seismically active Kuril-Kamchatka arc, the region has experienced over 30 earthquakes above magnitude 6.5 in the past century.

The earthquake’s epicentre lies near the source area of the 1952 M9.0 Kamchatka earthquake, which generated a devastating Pacific-wide tsunami. The recent event follows a series of foreshocks, including a M7.4 earthquake recorded on 20 July (USGS).

The IOC: A Global Framework for Tsunami Preparedness

The effectiveness of the response highlights the importance of long-term international collaboration in disaster risk reduction. Since 1965, the Intergovernmental Oceanographic Commission (IOC) has led global tsunami warning coordination, beginning with the establishment of the Pacific Tsunami Warning System following the 1960 Valdivia earthquake in Chile.

In the aftermath of the 2004 Indian Ocean tsunami, which claimed more than 220,000 lives, the IOC expanded its role by developing a global tsunami warning and mitigation network, now covering:

• The Pacific Ocean
• The Indian Ocean
• The Caribbean Sea
• The North-Eastern Atlantic and Mediterranean

Today, the IOC Tsunami Programme operates through a multi-layered approach that integrates:

• A dense network of seismic stations, deep-ocean sensors, and tide gauges
• Regional and national warning centres for rapid decision-making
• Community preparedness via the Tsunami Ready initiative, active in 43 countries

The programme also supports capacity-building efforts in Small Island Developing States (SIDS) and other high-risk coastal regions, while promoting real-time data exchange through platforms such as the IOC Sea Level Station Monitoring Facility.

These initiatives contribute to the objectives of the UN Decade of Ocean Science for Sustainable Development (2021–2030), with two clear and measurable targets, namely:

• To develop the warning systems’ capability to issue actionable and timely tsunami warnings for tsunamis from all identified sources to 100 percent of coasts at risk.
• And that 100 percent of communities at risk to be prepared and resilient to tsunamis by 2030 through efforts like the IOC Tsunami Ready Recognition Programme (TRRP).

For more information about tsunami preparedness and response measures, visit: www.tsunami.ioc.unesco.org