| Abstract Submission No. | ABS-1.2-0198 |
| Title of Abstract | Discovery of Active Hydrothermal Venting in the Southern Central Indian Ridge |
| Authors | VISHNU R MURALI*, Sunil V, P John Kurian |
| Organisation | National Centre for Polar and Ocean Research,Goa |
| Address | Flat 307, Kingston Plaza Near Vaddem Lake Vaddem, Goa, India Pincode: 403802 E-mail: vishnumarinegeo@gmail.com |
| Country | India |
| Presentation | Oral |
| Abstract | Hydrothermal vents are locations of primal significance as it stand crucial in understanding the seafloor processes, in terms of creating specialized ecological habitats as well as providing valuable mineral resources. Here, we report the discovery of active hydrothermal venting at the southern Central Indian Ridge (69.240 E, 23.360S), Indian Ocean, at water depths of 2700-3000m. The hydrothermal activity was identified in 2024 using a suite of sensors mounted on a Hugin Superior Autonomous Underwater Vehicle (AUV) surveying at an altitude of 55 m above the seabed. Hydrothermal plumes were observed in the water column as high-intensity backscatter in the multibeam echosounder data. Overall, 13 individual plumes were identified in the water column backscatter data. Correlated temperature anomalies in the CTD sensor onboard the AUV further confirmed the hydrothermal activity. Analysis of the high-resolution (1m) bathymetry of the vent field showed the presence of prominent axial volcanic ridge features and rift valleys running in a northeast-southwest direction. The vent field occurs on the flank of an axial ridge feature, typical of spreading ridges. An extensive presence of basalt mound clusters and volcanic fissures were seen adjoining the vent fields, highlighting the predominantly magmatic nature of the region. The active vent field occurs in the proximity of the MESO zone, an inactive basalt-hosted sulfide field where the episodic nature of hydrothermal venting has been established through radiochronological investigations. It is proposed that the region has continuous hydrothermal circulation with adequate magma supply owing to the formation of a basalt-hosted vent system; the emplacement of which is controlled by tectonic factors resulting in this episodic behavior of hydrothermal venting and opening of the current vent locations. |
| Keywords | Hydrothermal Vent, Central Indian Ridge, Tectono-magmatism, AUV survey |