New research highlights the severity of the 2022 Tonga explosion

Now, researchers have compiled a combination of before-and-after satellite imagery, drone mapping, and field observations collected by scientists at The University of Auckland – along with data from the Khaled bin Sultan Living Oceans Foundation Global Reef Expedition – to produce a tsunami simulation of the Tongan Archipelago. The outcomes indicate that the event resulted in a more than hour-long tsunami with waves up to 279 feet (85 meters) high one minute after the initial explosion.

“Despite its size and long duration, the mega-tsumani that resulted from Hunga Tonga-Hunga Ha'apai claimed few lives,” said Sam Purkis, professor and chair of the Department of Marine Geosciences at the Rosenstiel School. 

“The main factors that led to this, we suggest, are the quirk of the location, the COVID-19 pandemic, and increased evaluation drills and awareness efforts carried out in Tonga in the years prior to the eruption.”

Things, however, could have been far worse: The simulation also suggested that the eruption location relative to urban centers saved Tonga from a significantly more severe outcome.

“While 2022 may have been a lucky escape, other submarine volcanoes possess the capacity to spawn a future tsunami at the same scale, said Purkis, who is also chief scientist at the Khaled bin Sultan Living Oceans Foundation 

“This eruption holds important lessons for both past and future tsunami in Tonga and beyond. The eruption was an excellent natural laboratory to test hypotheses and models that can be deployed elsewhere to improve future disaster preparations, and better understand similar eruptions and subsequent tsunami as preserved in antiquity and in the geologic record.”

The study was published in a new analysis in Science Advances.