Destruction of underwater volcanoes mapped

Startling new images from the depths of the Pacific Ocean reveal one of the planet's most violent processes - the destruction of massive underwater mountains.

The pictures were created by sonar in waters up to four miles (6km) deep and expose how tectonic action is dragging giant volcanoes into a chasm in the seabed.

The volcanoes are strung out across several thousand miles of the ocean floor and are moving westwards on the Pacific tectonic plate at up to 8mm per year.

The images were captured along the highly active Tonga Trench fault line during a research expedition last summer.

The first images have been released to BBC News as the findings are presented to the annual conference of the American Geophysical Union.

Video courtesy of the Universities of Oxford and Durham and NERC.