Tonga’s underwater volcano, Hunga Tonga-Hunga Ha’apai, exploded in March 2022, creating a massive plume of ash and steam visible from space. The eruption was so powerful that it is being compared to the most powerful nuclear test ever conducted by the United States. In this article, we will explore the details of this explosive and historic event, the impact it had on the small island nation of Tonga, and the ongoing scientific research being conducted in the aftermath of the eruption.
Last year’s huge underwater volcanic event in Tonga may have been comparable in magnitude to the most powerful nuclear detonation by the US, according to a new study. Researchers used data from tide gauges, satellite, broken windows and other sources, along with eyewitness accounts to estimate that the eruption of the Hunga Tonga-Hunga Ha’apai volcano on 15th January 2022 likely involved five blasts. The last blast, which shattered windows and was felt around the world, released energy equivalent to 15 megatonnes of TNT, around 1,000 times more powerful than the Hiroshima bomb.
The eruption was characterized by both eruptions that thrust huge volcanic plumes into the stratosphere and explosions of steam, the latter causing sonic booms and the related tsunami. The scientists’ computer simulations suggest that the western coast of Tofua Island experienced waves of up to 45 metres in height, with signs of vegetation scars at the same altitude captured by satellite and drone data.
The Tonga eruption caused sensations of ground and building shaking for hours as far away as Fiji, nearly 500 miles away. With six people dead as a result of the event, including four in Tonga and two in Peru, who drowned due to the tsunami associated with the volcanic activity, the researchers explain that the low death toll can be attributed to factors such as the pandemic, evaluation drills, and awareness efforts carried out in the years prior to the event.
Tofua Island is sparsely populated and other areas that experienced large waves are uninhabited, while tourist resorts were closed due to Covid-19. Moreover, the main settlements in Tonga are located along the Nuku’alofa lagoon, which helped to dampen the waves. Inhabited islands elsewhere are located on a carbonate platform where shallow waters also help to reduce the impact of the waves.
This new study follows research published last year that revealed that the Tonga volcano eruption had the highest plume ever recorded, with an ash cloud that reached 57km (35 miles) in height. Dr Mohammad Heidarzadeh of the University of Bath, who was not involved in the new study but has also carried out research into the event, praised the latest work for offering the most detailed modeling of the Tonga tsunami so far, benefiting from a diverse observation dataset. In addition, Dr Heidarzadeh said that the new results were consistent with their previous study on the event, where they reported a maximum tsunami wave height of 90m.
This groundbreaking research provides important insights into the devastating impact of volcanic events on the environment and the importance of building resilience to mitigate their consequences. While the Tonga eruption caused significant damage and loss of life, measures such as pandemic preparedness and awareness-raising efforts can help to limit the impact of such disasters. As our planet faces an increasingly uncertain future due to climate change, this type of research is crucial to help safeguard vulnerable communities and ecosystems.
