Tonga volcano eruption was fueled by 2 merging chambers that are still brimming with magma 

 Researchers have mapped the magma plumbing system beneath Tonga's underwater volcano and discovered three magma chambers, two of which fed the record-shattering 2022 eruption. 

https://cdn.mos.cms.futurecdn.net/QN5ohZ3VuX4LdZ2vcReoC9.jpeg

https://www.space.com/tonga-volcano-still-burning-magma