Hydrothermal plumes above the East Scotia Ridge: an isolated high-latitude back-arc spreading centre

We have identified first evidence for the presence of submarine hydrothermal activity along the East Scotia Ridge an isolated back-are spreading centre located at 55-60 degreesS in the Atlantic sector of the Southern Ocean. Using a combination of in situ optical light-scattering sensor data, and total dissolvable Mn concentrations, we demonstrate the existence of hydrothermal plumes overlying two segments of this similar to 500 km ridge-crest; both segments exhibit anomalous topography and at least one segment is also underlain by an axial magma chamber seismic reflector. Future investigation of the fauna that inhabit these remote hydrothermal environments may provide an important 'missing link' between the distinct biogeographical provinces delimited from previous investigation of northern Atlantic versus eastern Pacific vent-sites. (C) 2000 Elsevier Science B.V. All rights reserved.