The tsunami created by the Tonga volcano caused a 90 meter high wave.

An international research team has warned that the explosion should serve as a wake-up call to protect people from similar incidents in the future. They also warn that tsunami detection and monitoring systems caused by volcanoes are 30 years behind instruments used to detect earthquakes.

Mohammad Heidarzadeh, general secretary of the International Tsunami Commission and professor at the University of Bath, co-authored the research with colleagues in Japan, New Zealand, England and Croatia.

For comparison, the largest tsunami waves from earthquakes preceding the Tonga event were recorded after the Tonga earthquake. Tōhoku near Japan in 2011 and the 1960 Chilean earthquake reaching 10 meters in height first. These were more devastating as the larger waves approached land.

it could be a great tragedy

Heidarzadeh says the Tonga tsunami should serve as a wake-up call to be more prepared and understand the causes and signals of tsunamis caused by volcanic eruptions. He says the Tongan tsunami killed five people and caused massive destruction. Had the volcano been located closer to human populations, the effects could have been even greater.. The volcano is about 70 km from Nuku’alofa, the capital of Tonga; This distance significantly minimized its destructive power.”

“This was a huge and unique event that highlighted this internationally. we must invest in developing systems to detect volcanic tsunamis, because they are about 30 years behind the systems we currently use to monitor earthquakes. We are not ready for volcanic tsunamis.”

The research was conducted by analyzing ocean observation data records of atmospheric pressure changes and sea level oscillations, along with computer simulations validated with real-world data.

atmospheric pressure waves

The research team found that the tsunami was unique. The waves were created not only by the water displaced by the volcanic eruption, but also by the huge atmospheric pressure waves that circulated the earth several times. This ‘dual mechanism’ created a two-part tsunami in which the first ocean waves generated by atmospheric pressure waves were followed more than an hour later by a second wave created by the displacement of water from the eruption.

This combination meant tsunami warning centers did not detect first waveBecause they are programmed to detect tsunamis based on water displacements rather than atmospheric pressure waves.

The research team also found that the January event was one of the few tsunamis powerful enough to circumnavigate the globe: recorded in all oceans and great seas of the world From the west coast of the United States in Japan and the North Pacific Ocean to coasts in the Mediterranean.

Aditya Gusman, a tsunami modeler at the New Zealand-based geoscience service, said: “The 2018 Anak Krakatau volcano and 2022 Hunga Tonga-Hunga Ha’apai eruptions have clearly shown us that Coastal areas surrounding volcanic islands are at risk of being hit by devastating tsunamis. While it may be preferable for low-lying coastal areas to be completely free of residential buildings, such a policy may not be practical for some locations, as volcanic tsunamis can be considered infrequent events.”

Co-author Jadranka Šepić, from the University of Split in Croatia, said, “The important thing is to have efficient warning systems, including both real-time alerts and training on what to do in the event of a tsunami or warning. Such systems save lives.. Also, monitoring of volcanic activity in volcanic areas should be organized and it is always a good idea to conduct higher quality research on volcanic eruptions and endangered areas.”

A separate study published in June by University of Bath atmospheric physicist Corwin Wright found that the Tonga explosion triggered atmospheric gravitational waves reaching the edge of space.

Reference work: https://www.sciencedirect.com/science/article/pii/S0029801822014810?via%3Dihub

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Environment department contact address:crisclimatica@prensaiberica.es