Monowai underwater volcano revealed by sonar
13 May 2012 Last updated at 18:14 BST
The violent rise and collapse of an underwater volcano in the Pacific Ocean is captured in startling clarity for the first time.
A team of researchers studying the Monowai volcano near Tonga recorded huge changes in height in the space of just two weeks.
The images - gathered by sonar from a research ship - shed new light on the turbulent fate of submarine mountains.
Published in the journal Nature Geoscience, the findings were made during a seabed survey last year.