Submarine Volcanoes of the Western Pacific

The way the sea floor is mapped has been revolutionised in the last decade by high resolution, multi-beam sonar systems, with follow-ups by manned and remotely-operated submersibles. Using these techniques, research groups from Australia, Germany, New Zealand and the USA are discovering much more about chains of underwater volcanoes in zones of tectonic plate convergence, known as 'arcs'. Researchers have found that up to 40 per cent of these underwater volcanoes in the southwest Pacific Ocean are emitting hot water, sulphur, and dissolved metals including iron.  In this lecture Professor Richard Arculus discusses the implications of these findings for the study of ore deposits, the growth of continents, and for the study of life in the oceans around deep sea hot water vents and the shallow water, pelagic photosynthesisers that critically depend on iron for their existence. Professor Arculus also discusses how the research will reveal more about the potential for underwater eruptions and volcanic collapses that can trigger tsunamis. This lecture was sponsored by the ANU College of Science as part of National Science Week 2006.