Notes on Vent Field Description:
Convincing evidence of active hydrothermal circulation on an ultra-slow ridge was first discovered in 1997 at several locations between 58.2° and 65.8°E on the Southwest Indian Ridge (SWIR) during a plume survey using optical sensors; this listing combines "SWIR, 63.5 E" from previous version of the database, which was listed at -27.9507, 63.5414; Tao et al. (2009): "A hydrothermal field combined with ultramafic rocks was found at 63.5°E...CH4, Eh, H2S and temperature anomalies were detected. Massive sulfide, oxidized chimney and sediment were sampled. Serpentinized ultramafic rocks were recovered at a nearby site. This would be the first ultramafic-hosted hydrothermal system found at SWIR."
Year and How Discovered (if active, visual confirmation is listed first):
1997 plume only; 2009 DY115-20 Leg 7 plume and deposits
Discovery References (text):
(plume only) German et al., Nature 395, 490-493, 1998, Hydrothermal activity along the southwest Indian ridge.
(plume and deposits) Tao et al. (2009) New hydrothermal fields found along the SWIR during the Legs 5-7 of the Chinese DY115-20 Expedition. AGU Fall Meeting abstract #OS21A-1150.