Scientists Return With Rich Haul From Kermadec

NEWS RELEASE, 17 OCTOBER 2004
SCIENTISTS RETURN WITH RICH HAUL FROM KERMADEC AREA

The deepwater research ship Tangaroa berthed at Tauranga today with a shipload of new knowledge and discoveries about the ocean floor northeast of New Zealand.

During the past three weeks the 27 scientists on the ship have mapped, probed and sampled the northernmost section of the Kermadec Arc, which stretches from the Bay of Plenty to Tonga.

Along the 550km stretch of seafloor under scrutiny, they captured three-dimensional images of several previously unknown volcanoes, including one measuring eight kilometres by five kilometres ? about the size of Wellington Harbour.

Throughout the voyage, and particularly when volcanoes were discovered, Tangaroa stopped and lowered electronic "sniffer" equipment to collect information about volcanic plumes rising from the submarine volcanoes and hydrothermal vents on the seafloor.

The plumes are rich in dissolved iron, manganese, and copper, with lesser concentrations of zinc, lead and gold. As well as depositing metallic minerals on the seafloor, they are an important source of trace elements in the world's oceans.

And apart from minerals, submarine volcanoes produce large amounts of methane, hydrogen sulphide, and carbon dioxide gases. At one of the more active volcanoes, the scientists deployed equipment that will enable them to estimate the volumes of greenhouse gases being produced. The equipment will be retrieved next year.

The voyage was the third in a series of expeditions that started in 1999, aimed at finding out as much as possible about the 2500km stretch of volcanic seafloor between New Zealand and Tonga. The Kermadec Arc marks the boundary between the Australian and Pacific tectonic plates.

The voyages are a collaboration involving the Geological and Nuclear Sciences institute (GNS), the National Institute of Water & Atmospheric Research (NIWA), America's National Oceanic and Atmospheric Administration (NOAA), and the Australian National University (ANU).

Voyage leader Cornel de Ronde of GNS said knowledge gained during the past three weeks would contribute to the understanding of fields such as potential seabed energy sources, global warming, greenhouse gases, the movement of ocean currents, and super-tough heat-loving micro-organisms.

Scientists believe that life on earth may have begun next to volcanic seafloor hotsprings such as those they have been probing during the past three weeks. The organisms living in this hostile environment may have potential applications in areas such as manufacturing industries and pharmaceuticals.

" Much of what we've been doing is ground-breaking science. There will be follow-up voyages to build on the platforms we have set up," Dr de Ronde said.

" The large amount of data and the samples we've collected from the ocean floor will be scrutinised by many scientists in the coming months. It will add significantly to the body of knowledge about New Zealand's offshore territory."

Parts of the voyage have relevance to safety as well as science, according to NIWA scientist and co-leader of the voyage Ian Wright.

" Five or ten years ago people didn't believe you could get these caldera volcanoes in submarine settings.

" The conventional wisdom of the 1970s was that you couldn't have explosive submarine volcanic eruptions, and if you did they were very shallow. However, there's been a major change in our thinking.

" What we're trying to do is gain an understanding of when eruptions occurred so that we can have some sense about tsunami generation. These submarine volcanoes are potential sources of tsunami."

With much of New Zealand's coastline exposed to the Pacific Ocean, knowing more about volcanic triggering of tsunami is likely to have potential benefits.

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