10th International Congress of the Brazilian Geophysical Society
Rio de Janeiro, Brazil, Nov. 19-23, 2007
Special Technical Sessions (Nov. 20, 2007):
Tectonic & Volcanic Processes at Mid-Ocean Ridges
Co-Chairs: Marcia Maia (IUUM/UBO, France), Sidney Mello (LAGEMAR/UFF, Brazil), Jian Lin (Woods Hole Oceanographic Institution, USA)
Mid-ocean ridges provide a unique tectonic window for investigating oceanic crustal and mantle processes at various scales. Melts from the partially molten mantle rocks are focused beneath mid-ocean ridges to form magma lens and oceanic crust and provide heat for hydrothermal circulation. Mantle rocks may also outcrop directly on the seafloor at slow- and ultraslow-spreading ridges. We invite contributions of recent work on morphological, geological, geophysical, and geochemical studies of mid-ocean ridges at any locations in the world oceans. Both field observational and theoretical modeling studies of ridge processes are encouraged. Example key issues to be discussed include 1) the role of spreading rate, hydrothermal cooling, and mantle temperatures and source geochemistry in controlling the ridge dynamics; and 2) the links between tectonic, hydrothermal, and mantle processes at mid-ocean ridges.
Deep-Sea Hydrothermal Vents & Biology
Co-Chairs: Nadine Le Bris (IFREMER, France), Francoise Gaill (CNRS, France), Paulo Suguio (IOUSP, Brazil), Chris German (Woods Hole Oceanographic Institution, USA)
Deep-sea hydrothermal vents and cold seeps ecosystems can function independently of sunlight, with chemosynthesis being the primary energy source for the development of complex faunal communities in these environments. Today much of the 60,000 km of the mid-ocean ridge still remains unexplored. Magmatic processes controlling rifting may separate hydrothermal vent sites over many ridge segments. Faunal composition over large distances is not easily predictable; it may relate to larval dispersal and chance recruitment as vent fields may be separated by tens to hundreds of kilometers. We invite contributions to broaden the discussions on the most recent scientific discoveries on hydrothermal vents and biology, setting the necessary framework essential for environmental assessment of these chemosynthetic ecosystems and to promote further potential international collaboration with high-quality internationally-led research, and diverse expertise (geological, biogeochemical, physical, biological, and from microbes to megafauna, from taxonomy to physiology).
