"Tonga's Merging Magma Chambers: A Volcanic Eruption Waiting to Happen"

Scientists have mapped the magma system beneath the Hunga Tonga-Hunga Ha'apai volcano, revealing that the massive 2022 eruption was likely caused by the merging of two magma chambers. The eruption, which was the most intense lightning storm ever recorded and triggered a mega tsunami, ejected about 30% of the magma from a shallow chamber, forming a caldera. Despite the eruption, up to 6.2 cubic miles of eruptible magma may still be present beneath the volcano. The study, published in Science Advances, used gravity variations to image the magmatic system, a rare approach for submarine volcanoes. The findings help understand the volcano's structure but do not pinpoint the eruption's trigger.