Two New Zealand scientists, who have just returned from witnessing an erupting undersea volcano near the Island of Guam in the Mariana Arc, say the volcano is supporting a thriving community of marine life in spite of the eruptions.
Marine geologists Cornel de Ronde and Heidi Berkenbosch, of GNS Science, were part of an international consortium of scientists who captured dramatic video of the eruptive activity of submarine volcano Northwest Rota-1. It remains the only submarine volcano that has been directly observed while erupting.
Scientists have returned from exploring three submarine volcanoes in the Kermadec Arc where they found evidence of a recent large eruption at one of the volcanoes.
Dr de Ronde said it was the third time scientists had visited NW Rota-1 since 2004. Each time they have deployed a remotely operated vehicle to capture video of the ongoing eruptions.
Expedition leader William Chadwick, of Oregon State University, said the volcano had been erupting continuously for five years, and possibly longer. “ It has built a new cone that is 40 metres high and 300 metres wide since we last visited in 2006,” Dr Chadwick said.
New Zealand scientists are part of a consortium of US and Canadian science organisations studying hydrothermal and volcanic activity in the world’s oceans.
Dr de Ronde said New Zealand scientists are invited to participate in the research voyages because of their expertise in analysing submarine hydrothermal activity and in understanding how mineral deposits form on the sea floor.
NW Rota-1 is a cone volcano that is as high as a 12-story building and its summit comes within 520m of the sea surface.
Dr de Ronde said it was a “juvenile” submarine volcano in terms of its geological evolution.
“ We are particularly interested in this volcano because it is erupting large amounts of elemental sulphur onto the sea floor. This is likely to be the beginnings of a sea floor mineral deposit.”
There are many similar submarine volcanoes in the Kermadec Arc, northeast of New Zealand, although they are more mature in their geological evolution.
The unusual ecosystem being supported at NW Rota-1 includes shrimp, crab, limpets and barnacles, some of which were new species.
Expedition member Verena Tunnicliffe from the University of Victoria, Canada, said the marine life was specially adapted to their environment and were thriving in harsh chemical conditions that would be toxic to most other life forms.
“ There is a large population of shrimp that have intriguing adaptations that enables them to live on an active volcano,” Professor Tunnicliffe said.
The studies at NW Rota-1 were important because it provided a one-of-a-kind natural laboratory for investigating undersea volcanic activity and its relation to ecosystems at hydrothermal vents where life on Earth may have originated.
“It is unusual for a volcano to be continuously active, even on land,” Dr de Ronde said.
“This presents scientists with a fantastic opportunity to learn about processes that we haven’t been able to directly observe before,” he said.
During the recent expedition, which was aboard the University of Washington’s R/V Thomas G Thompson, the scientists deployed Jason-2, a remotely operated vehicle (ROV) operated by Woods Hole Oceanographic Institution.
Dr de Ronde said it was amazing how close the Jason-2 could get to eruptiing vents because the pressure at a depth of 520m in the ocean kept the energy released from the volcano from becoming too explosive.
The voyage was funded by the National Science Foundation in the US. The international team included scientists from New Zealand, Oregon State University, University of Washington, University of Victoria, NOAA’s Pacific Marine Environmental Laboratory, and Japan.
More information, including videos, is available at: http://nwrota2009.blogspot.com/
See Heidi's account of her trip on the offical GNS Science Blog here.
