14/05/2012 10:59 BST | Updated 14/05/2012 11:03 BST

Monowai Submarine Volcano, Growth And Collapse Seen With Sonar Imaging (PICTURES, VIDEO)

The rapid collapse and growth of an underwater volcano north of New Zealand has been captured with sonar imaging.

A research team found violent rises and falls in the Monowai submarine volcano in the Tonga-Kermadec Arc in the space of just a fortnight.

Published in the Nature Geoscience journal, the findings reveal the Monowai eruption added around 300 million cubic feet (9 million cubic metres) or rock to its summit in just five days.


As Our Amazing Planet points out, that is equivalent to a volume equal to 3,500 Olympic-size swimming pools.

The paper adds: “The collapse and growth rates implied by our data are extremely high, compared with measured long-term growth rates of the volcano, demonstrating the pulsating nature of submarine volcanism and highlighting the dynamic nature of the sea floor.”

Lead author Tony Watts of Oxford University told the BBC the findings, collected last spring, were: “A wake-up call that the sea-floor may be more dynamic than we previously thought.”

He said: “I’ve spent my career studying the seabed and have generally thought it pretty stable so it’s stunning to see so much change in such a short space of time.”

The summit is approximately 132 metres (433 ft) below sea level and was first spotted from an aircraft in 1944.

Professor Watts added: "This is a violent exchange of rock into the water - it could destabilise the cone and cause a landslide which in principle could cause a tsunami."