Lessons from the Tonga Tsunami

Every natural disaster is an education for those engaged in emergency response and preparedness, and emergency managers around the Pacific have already begun to process what they’ve learned (and continue to learn) from the tsunami generated by the Hunga Tonga-Hunga Ha’apai volcano on January 15.

Some lessons seem small and practical, but are terribly important for coordinated communication among emergency responders: If you’re an emergency manager, geologist, engineer, or other specialist whose role at your organization includes disaster response, remember to verify that your contact information is up to date on all contact sheets and distribution lists maintained by partner agencies. Each state, county, and jurisdiction maintains contact lists and alerts differently. Depending on your job or role, you might need to be on multiple states’ lists, too.

As the Tonga tsunami waves began arriving along the west coast of the continental U.S. on the morning of January 15, it became clear that public outreach and education is still needed to improve people’s understanding of the hazard. Those who ignored the Tsunami Advisory and went to the beach to watch the tsunami, or even to attempt to surf it, either did not understand the difference between a wind-driven wave and a tsunami, or underestimated the power and potential danger of even a “small” tsunami surge.

Explore tsunami info & resources:

NOAA / National Weather Service: U.S. Tsunami Warning System
National Tsunami Hazard Mitigation Program
NOAA Center for Tsunami Research: Pacific Marine Environmental Laboratory
NWS Tsunami Education and Outreach Materials
The Tsunami Zone


Critical Tsunami Info for Oregon Disaster Response Planners

CREW board member Yumei Wang produced the Cascadia Tsunami Casualty Estimates Report (2021) for the Oregon coast, now available on the Oregon Health Authority website. The casualty estimates, as well as descriptions of direct health effects of tsunamis on survivors, can be used by coastal hospitals, communities, and emergency planners to help shape realistic planning scenarios for emergency response exercises, such as Cascadia Rising 2022.

Underlying the report’s tsunami casualty estimates is the assumption that everyone in Oregon’s tsunami inundation zones is quick to evacuate on foot using optimal tsunami evacuation routes immediately after the Cascadia earthquake. In spite of this efficient evacuation, a large tsunami causes an estimated 18,667 fatalities and 819 injuries.

Funding for the report was provided by the Health Security, Preparedness and Response (HSPR) Program of the Oregon Health Authority.

Yumei Wang is owner of Sustainable Living Solutions LLC, as well as Senior Advisor on Infrastructure Resilience and Risk in the Civil and Environmental Engineering department of the Maseeh College of Engineering and Computer Science at Portland State University.