Scientists in Japan have found that the Kikai Caldera, a large underwater volcano south of Kyushu, is slowly filling with new magma. This volcano caused a huge eruption about 7,300 years ago, which changed the local area and sent a lot of ash into the air.

Researchers from Kobe University used special sound wave technology to look deep under the sea floor. They discovered a large space under the volcano where new liquid rock, called magma, is collecting. This shows that the volcano is slowly rebuilding after its massive eruption long ago.

The main result of this study is a better understanding of how supervolcanoes recover after a big eruption. Scientists say Kikai is not expected to erupt soon, but learning more about this volcano can help them watch for changes in other large volcanoes around the world.