It could be a great tragedy
The first tsunami wave triggered by the January 2022 submarine volcano eruption near Hunga Tonga in Ha’apai, Tonga, reached roughly 90 meters in height — nine times higher than the devastating waves observed in 2011 after the Tohoku earthquake, as reported by new research.
A team of international researchers warns that this eruption should serve as a wake‑up call to better protect people from similar events in the future. They also note that tsunami detection and monitoring systems for volcano-induced waves are about 30 years behind those used to track earthquakes.
Mohammad Heidarzadeh, general secretary of the International Tsunami Commission and a professor at the University of Bath, co-authored the study with colleagues from Japan, New Zealand, England and Croatia.
For context, the largest tsunami waves from earthquakes preceding the Tonga event were generated by the 2011 Tōhoku earthquake near Japan and the 1960 Chilean earthquake, which produced waves up to about 10 meters in height. Those earthquakes caused more destruction as the waves reached land.
Atmospheric pressure waves
Heidarzadeh emphasizes that the Tonga tsunami should prompt greater preparedness and understanding of the causes and signals of tsunamis triggered by volcanic eruptions. He notes that five people lost their lives and that the destruction was substantial. Had the volcano been closer to populated areas, the impact could have been far worse. The volcano lies about 70 kilometers from Nuku’alofa, the capital of Tonga, a distance that mitigated its destructive power.
He emphasizes that this was a rare, large event that highlights a global need: invest in systems capable of detecting volcanic tsunamis, as they lag behind the tools used to monitor earthquakes by about three decades. He argues that the world is not prepared for volcanic tsunamis.
The research analyzed ocean observation data, including atmospheric pressure changes and sea level oscillations, and was supported by computer simulations calibrated against real-world data.
Dual mechanism and the detection challenge
The study found the Tonga event was distinctive because the waves formed not only from water displaced by the eruption but also from large atmospheric pressure waves that circled the planet multiple times. This “dual mechanism” produced a two‑part tsunami: the first ocean waves generated by atmospheric pressure waves occurred, then more than an hour later a second wave formed from water displacement caused by the eruption.
This combination helped explain why some warning centers did not detect the first wave, as systems were programmed to recognize tsunamis based on water movement rather than atmospheric pressure fluctuations.
Researchers also noted that the January eruption was powerful enough to travel around the globe, with recordings appearing in every ocean and sea from the west coast of the United States and Japan across the North Pacific to Mediterranean shores.
Aditya Gusman, a tsunami modeler with New Zealand’s geoscience service, remarked that the 2018 Anak Krakatau eruption and the 2022 Hunga Tonga eruption demonstrate how coastal zones around volcanic islands remain at risk for devastating tsunamis. While relocating low-lying areas away from housing might be ideal, it is not always practical, as volcanic tsunamis can be infrequent yet catastrophic.
Co-author Jadranka Šepić of the University of Split in Croatia stressed the importance of efficient warning systems, including real-time alerts and practical guidance on actions to take during a tsunami or warning. She also urged continued monitoring of volcanic activity in at‑risk regions and ongoing high‑quality research on volcanic eruptions and endangered areas.
A separate June study by Corwin Wright, an atmospheric physicist at the University of Bath, found that the Tonga explosion triggered atmospheric gravitational waves that extended to the edge of space.
Remarkable work on this topic is cataloged in the scholarly record and is cited within ongoing research on volcanic tsunamis and atmospheric interactions. This citation is acknowledged within the broader body of literature on tsunami science.
The research is based on a synthesis of oceanographic records, atmospheric data, and validated computer models, reflecting coordinated international efforts to improve early warning and risk mitigation for volcanic tsunamis.
Overall, the findings underscore the critical need for enhanced monitoring infrastructure, updated threat assessments, and community preparedness that accommodates the unique behavior of volcanically induced tsunamis.
Further reference to the study and related work can be found in the scholarly publication cited within the research community, with additional details available through academic databases and institutional repositories.
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