Published new bathymetry map of Hunga Tonga-Hunga Ha'apai

 

A new bathymetry map of the volcano's caldera has been released today.

Professor Shane Cronin from the University of Auckland (New Zealand) in collaboration with Tonga Geological Services participated in field research to map the undersea caldera over the past two and a half months.

The volcano caldera is currently 4 km (2.5 miles) wide reaching a depth of 850 meters! The pre-eruption caldera depth was measured at a depth about 150 meters below sea level. The volcanic ejecta volume has been measured at least 6.5 km3 of pyroclastic material. "If all of Tongatapu, the main island of Tonga, was scraped to sea level, it would fill only two-thirds of the caldera", says professor Cronin.

A comparison of pre-eruption bathymetry (depth) maps from 2015 and 2016 with the current situation depicts dramatic morphological changes to the caldera. Besides general deepening, a massive area of the interior cliffs has been destroyed, mainly at the southern rim of the crater.

Along with the recent caldera map, another bathymetry map related to the area around the volcano has been released by New Zealand's National Institute for Water and Atmospheric (NIWA).

The Hunga Tonga-Hunga Ha'apai volcano is not the only threatening volcano in the southwest Pacific region, there are at least 10 undersea volcanoes to erupt at similar scale.

Source: Shane Cronin and BBC