Scientists were studying the volcano as it awoke from a 50-year sleep to spew ash into the atmosphere for several weeks in 2017.
Dr Fabien Albino, from the University of Bristol’s School of Earth Sciences, and the study’s lead author, explains how they found the mountains’ magma can move horizontally as well as vertically.
Dr Albino said: “Thanks to the ground information data, we found magma was moving before the eruption, not below the Agung volcano, but between the volcanos.
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