NIWA surveys seabed around Whakaari/White Island

NIWA scientists are surveying seafloor in the waters around Whakaari/White Island in the Bay of Plenty.

Mapped in 2005 and again in 2019, the area is known for its underwater vents and canyons. However, the eruption of Whakaari/White Island in December last year is likely to have significantly altered the seafloor landscape.

NIWA marine geologist Dr Joshu Mountjoy said: “What is visible from sea level is only a small part of the volcano – most of it is under the ocean so we want to see how that submarine environment has changed.”

Scientists onboard NIWA research vessel Tangaroa will map the area using a multibeam echo sounder which emits sound beams that map the seafloor and objects in the water column such as gas bubbles.

Water samples will also be taken to measure methane and carbon dioxide gas levels which will help detect the presence of underwater seeps linked to volcanic activity.

Dr Mountjoy explained that the aim of the survey is to understand how these sedimentary deposits have changed and if there have been any submarine landslides.

“There is also the potential to see new hydrothermal vents – particularly in shallow water close to the island. No-one has collected water column imaging close to Whakaari so this is an incredible opportunity to discover new areas of volcanic activity.”

The scientists will also be looking for significant changes that may have affected the ecology of the area that may require further work.