Sunday, June 24, 2012

Deep-sea volcano ‘discovered’

Australian scientists claim to have discovered a deep-sea volcano, with unique organisms dated from thousands of years ago. A team, led by the South Australian Research and Development Institute, discovered the cone-shaped volcano some 100 nautical miles offshore and 2,000 metres deep in the Great Australian Bight Marine Park Benthic Protection Zone. Organisms living on the feature could be unique to the location and date back “thousands of years,” say the scientists. While there are similar volcanic features outside the zone, this is significant because it is located in an area now protected from human disturbance, preserving its biological diversity into the future. Dr David Currie, who led the exploratory expedition through the GAB Marine Park BPZ, aboard marine facility the RV Southern Surveyor, says the 800 metre diameter volcano rises 200 metres out of a generally flat and featureless seafloor. He said:“Previous work by Geoscience Australia mapping volcanic features on seismic data in the region suggests that it is likely to be an igneous build-up formed when molten magma pushed toward the surface thousands of years ago. “It’s a phenomenal find, and quite remarkable that we passed right over the top of it 100 nautical miles offshore in the middle of the Benthic Protection Zone. We were mapping a strip of seabed less than two nautical miles wide, and it could have taken us hundreds of survey lines to locate it.” Dr Currie said the extinct volcano found within the Marine Park was from the Eocene Epoch dating back 48 million years. It was likely to support a diverse community of long-lived, slow-growing, organisms such as stony corals, hydroids, gorgonians and glass sponges. “The Southern Surveyor is the only vessel in Australia capable of such deep sea exploratory research. We are now very keen to go back and sample around this volcanic feature and assess the biological community that it supports. There may be some unique aspects to this feature in the GAB that makes its immediate ecological environment important,” he said. The Aus dollars 450,000 expedition, funded by the Australian Government, swath mapped over 150 square nautical miles of seabed throughout the park, and sampled seafloor biodiversity as well as the water’s conductivity, temperature and nutrient content.

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