01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-09-0350 |
| Title of Abstract | Evolution of a seamount chain through a leaky fracture zone: Insights from the Arabian sea |
| Authors | Twinkle Damodharan*, C.M. Bijesh , V. Yatheesh , P. John Kurian |
| Organisation | CSIR- National Institute of Oceanography |
| Address | Geologial Oceanograpgy Division, CSIR-National Institute of Oceanography, Dona Paula Panjim, Goa, India Pincode: 403004 E-mail: twinkle.nio@csir.res.in |
| Country | India |
| Presentation | Oral |
| Abstract | Seamounts play a vital role in shaping ocean ecosystems and influencing oceanographic conditions, and they have been extensively studied over the past decades. They also provide important insights into lithospheric and mantle processes, recording the complex interplay among tectonics, magmatism, and plume dynamics. In the eastern Arabian Sea, twelve seamounts are identified using newly acquired multibeam bathymetry (MBES) resembling a linear seamount chain, which runs parallell to the Rudra Fracture Zone (RFZ). The high-resolution bathymetric data reveals various morphologies, including steep, conical seamounts with centralized summits and also elongated, ridge-like structures aligned with the fracture zone. These forms suggest both localized volcanic centres and fissure like eruptions channelled by tectonic lineaments. Gravity anomalies show a strong correlation with mapped seamounts and reveals the extension of long linear trace of the RFZ northward up to ~12°N. Band-pass filtered gravity data further highlight volcanic features masked by sediment cover and reveal the fracture zone at multiple scales: short wavelengths (2⿿50 km) emphasize individual small volcanic edifices; intermediate wavelength (2⿿100 km, 2⿿150 km) delineate the continuous fracture zone and crustal offsets; and long wavelengths (2⿿250 km) shows broader lithospheric segmentation. The seamounts become larger and more voluminous toward the south, indicating enhanced magmatism in the younger part of the crust. Seismic profiles across the RFZ shows basement offsets, crustal thinning, and chaotic reflections, indicating deformation and weakened lithosphere. The proximity of the RFZ to the Laccadive Plateau further links with the Réunion hotspot, and the weakened lithosphere. Thus the RFZ is described as a leaky transform fault rather than a passive lithospheric boundary. Its structural fabric has provided pathways for magma ascent, guiding the growth of a volcanic chain while accommodating changes in spreading patterns. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Rudra fracture zone, Seamount chain, Leaky fracture zone, Arabian sea, Multibeam bathymetry |
| For Awards | no |