Saturday 15 January 2022

Tsunami warning issued across the Kingdom of Tonga following an eruption on the Hunga Ha'apai underwater volcano.

A tsunami warning was issued to people living in coastal areas on all the islands of the Kingdom of Tonga on Thursday 13 January 2022, following an eruption on the Hunga Ha'apai underwater volcano, which produced a column of gas and ash about 20 km high. In the event, the largest wave observed was only about 30 cm high, which reached Nuku'alofa on the north coast of the island of Tongatapu at about 12.30 pm local time. The volcano began its current eruptive cycle on 20 December 2021, prior to which it had been inactive since 2015.

GOES-17 satellite imigary of the 13 January 2022 Hunga Ha'apai underwater volcano eruption. University of Wisconsin Madison/Space Science and Engineering Center/CIMMS Satelite Blog.

Hunga Ha’apai lies 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.

See also...

Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter.