Warnings have been issued to air and sea traffic after Home Reef Volcano, an ephemeral island volcano in Tonga, erupted eight times in a 48 hour period between 18 and 20 September 2022. Aviators have been warned not to approach within three kilometres of the volcano, due to the dangers of volcanic ash to aircraft engines, and mariners have been advised not to approach the volcano and to be vigilant for rafts of floating pumice (volcanic rock with numerous large pore-spaces which can float on water), which can be damaging to boats.
Home Reef is usually beneath the water, but the formation of temporary islands from ash effusions which are subsequently washed away has previously recorded in 1852, 1857, 1984 and 2006. The volcano began to erupt again on 10 September 2022, and by 17 September had formed an island with an area of 24 300 m², which by 23 September had grown to 32 375 m².
Home Reef ies on the Tonga/Kermadec Ridge, and is fed by the subduction of the Pacific Plate beneath the Australian Plate along the Kermadec/Tonga Trench. As the Pacific Plate sinks into the Earth, it is warmed by the heat from the planets interior. This leads to partial melting of the Pacific Plate, with some of the melted material rising through the overlying Australian Plate as magma, fuelling the volcanos of the Kermadec/Tonga Ridge.
Diagram showing subduction along the Tonga Trench, and how this feeds the volcanoes of the Tonga Volcanic Arc. York University.