Mapping magma reservoirs under the ocean
A new method has been used to map medium to large size magma reservoirs under the oceans and screen them for eruption hazard potential.
The 2022 eruption of the Hunga volcano in the Tonga-Kermadec island arc was the largest explosive eruption recorded. Yet, the magma plumbing system under this volcano is unexplored due to inherent difficulties caused by its submarine setting.
BTW researchers used marine gravity data derived from satellite altimetry combined with multibeam bathymetry to model the architecture and dynamics of the magmatic system before and after the January 2022 eruption. The study provides geophysical evidence for significant melt accumulation in three reservoirs at shallow depths (2 to 10 km) under the volcano. It was estimated that less than ~30% of the existing melt was evacuated by the main eruptive phases, enough to trigger caldera collapse.
The new method has the ability to map medium to large size magma reservoirs under the oceans and screen them for eruption hazard potential and as such has global application.
Read the published journal paper(external link).
Craig Miller
Beneath the Waves Programme Leader & Volcano Geophysicist