Since August a large accumulation of pumice has been drifting in the Southwest Pacific towards Australia. Researchers at the GEOMAR Helmholtz Centre for Ocean Research Kiel, together with colleagues from Canada and Australia, have now identified the origin of this pumice raft. It is a so far nameless underwater volcano in Tongan waters. The study has been published online in the international Journal of Volcanology and Geothermal Research.
Stones do not float in water. This is a truism. But there is hardly a rule without exception. In fact, some volcanic eruptions produce a very porous type of rock with a density so low that it does float: Pumice. An unusually large amount of it is currently drifting in the Southwest Pacific towards Australia. When it was first sighted in the waters of the island state of Tonga at the beginning of August, it almost formed a coherent layer on the ocean’s surface. The "pumice raft" made it into headlines all over the world.
Various underwater volcanoes were discussed at that time as the potential source. But a direct proof for the exact origin of the pumice was missing so far. Researchers at the GEOMAR Helmholtz Centre for Ocean Research Kiel (Germany), together with colleagues from Canada and Australia, are now publishing evidence in the Journal of Volcanology and Geothermal Research that clearly identifies the culprit. It is a so far nameless underwater volcano just 50 kilometres northwest of the Tongan island of Vava'u. “In the international scientific literature, it appears so far only under the number 243091 or as Volcano F", says Dr. Philipp Brandl of GEOMAR, first author of the study.
Read more at Helmholtz Centre for Ocean Research Kiel (GEOMAR)
Image: The volcanic island of Fonualei, which is not far away from the underwater volcano "F". Photo: Philipp Brandl/GEOMAR (CC BY 4.0)