FEATURE
AND THE MOST
EXPLOSIVE
VOLCANIC ERUPTION
THIS CENTURY BY MICHAEL CLARE
AN ERUPTION THAT SHOOK THE WORLD
The entire world was shaken on the 15th of January 2022 by the eruption of a volcano in the South Pacific. The blast was so powerful that it created a pressure wave that travelled at least three times around the planet and caused a tsunami that reached the other side of the Pacific Ocean. The ground motions generated by the eruption were recorded by earthquake monitoring stations worldwide. Volcanic ash and steam were shot almost 60 kilometres into the air, forming a plume that was visible from space. This remarkable eruption was the most explosive ever recorded with modern instruments and was likely the largest of any underwater volcano since 1883 when Krakatau erupted in the Sunda Strait, offshore Indonesia.
GLOBAL AND LOCAL IMPACTS
Despite its power, there was little warning before the
38 SUBMARINE TELECOMS FORUM MAGAZINE
sudden eruption of Hunga Tonga-Hunga Ha’apai (now referred to as Hunga Volcano); a volcano that lies mostly under the sea in the waters of the Kingdom of Tonga. The islands of Tonga and Fiji were impacted by even larger tsunamis, some of which reached tens of metres height when they made landfall, dwarfing the islands that they inundated. Fortunately for the local population, tsunami warning and evacuation strategies were extremely effective. However, in the midst of a volcanic crisis, the island nation of Tonga suddenly found itself cut off from global communications, at a critical time for disaster response. Just over an hour after the largest explosion of Hunga Volcano on 15th January 2022, Tonga’s only international subsea telecommunications cable was damaged, cutting connections from Tonga to Fiji. A domestic subsea cable that provides connections to island groups within Tonga was also broken, only 15 minutes after the main explosion.