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

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