Seafloor Geomorphology and Processes on the Western Continental Margin of India based on Multibeam Acoustic Backscatter Data Analysis

ABSTRACT

An assessment of the multibeam sonar data of the central Western Continental Margins of India has been carried out to evaluate the seafloor geomorphology and processes by examining the geomorphological attributes e.g., slope, sediments, structures, etc. associated with geomorphic features. The variation in relief and the features located in the region have been mapped and interpreted collectively by utilizing several geospatial mapping tools. The backscatter strength across the area, apparently congruent with the local relief, has helped to examine the sediment movement on the seafloor. The prominent features found in the region include faults, pockmarks, mounds, submarine terraces, and submerged fossil reefs. Several areas with varying topography engender comparable fractal dimension at short scale breaks, and the probability density functions (PDFs) utilizing backscatter data depicting overlapping classes. The present study highlights how fractals and scale break parameters can be utilized to determine the seafloor processes and associated sedimentological dynamics in a complex geographical environment with strong bottom currents, seasonal upwelling, and faulted structure. The role and impact of the various geomorphic processes on the reworking of sediment movement and the overall progression of the seafloor morphology has been revealed for the first time in this part of the ocean bottom.

KEYWORDS:

• Arabian sea
• continental margin landforms
• fractal dimension
• geomorphic processes
• multibeam sonar
• mapping
• seafloor geomorphology
• sediment movement

Acknowledgements

The authors are thankful to the Director, CSIR-National Institute of Oceanography, for his permission to publish this work. The critical review by the editor and the reviewers is appreciable and has substantially improved the quality of the manuscript. The multibeam data was acquired under the Exclusive Economic Zone mapping program of the Ministry of Earth Sciences, Govt. of India. This paper is partly based on the thesis submitted for PhD by SD at Banaras Hindu University, Varanasi, India. This is NIO contribution number 6082.

Additional information

Funding

Department of Science and Technology, Ministry of Science and Technology SR/FST/EST-110/2011(C); Ministry of Earth Sciences MoES/EC/EEZ/32/2012-PC-II;University Grants Commission F560/3/DRS/2012(SAP-I)