Under Part VI of the UN Convention on the Law of the Sea 1982 (UNCLOS), coastal states have sovereign and economic rights over the resources of their continental shelf out to a idstance of 200 nautical miles (M) from thier territorial sea baselines. However, as per the provision of Article 76 of UNCLOS, these rights can be extended beyond 200 M it it can be demonstrated that the shelf extends beyond this distance throughout the natural prolongation of its land territory (See Figure below).Determining the extent of this continental prolongation from the landmass, and hence defining the outer limit of the continental shelf, forms the basis of the Indian Continental Shelf Programme.
The Indian Continental Shelf Project which commenced during November 1999, is a multi-institutional and multicrore national mission that seeks to gather , analyse and document the requisite scientific and technical information that would help define the country’s extended shelf boundaries beyond 200 M as per the UNCLOS provisions. The Indian endeavours towards this ultimate goal are being spearheaded by the National Centre for Antarctic and Ocean Research (NCAOR). Underpinning our efforts has been a comprehensive multi-institutional marine geophysical survey and data analysis programme comprising state-of –the –art multi-channel seismic reflection, refraction, gravity and magnetic data profiling.
The data acquisition work was initiated through a contractual agreement on the 17th July 2002 and was completed on the 7th of February 2004. Spread over 385 days of fair-weather period, around 31,000 km of seismic reflection, gravity and magnetic data were collected in and off the EEZ of India. In addition, for the first time in the country, 90 state-of-the-art Ocean Bottom Seismometers (OBS) were successfully deployed along several seismic transects to constrain the velocities from the reflection data as well as to develop a crustal model of the area.
Considering the scope of the work, the post – processing and interpretation of the geophysical data was undertaken by three of the leading National Institutes, viz., NCAOR, NGRI and NIO. The National Hydrographic Office (NHO) was the load agency for the acquisition , processing, interpretation delineation of the 2500-m isobaths as well as the foot of the continental slope. Other Indian Agencies involved in the Project during the data acquisition phase were the ONGC, GSI and the DGH. All the policy aspects related to the delineation exercise are being handled by the Ministry of Earth Sciences and the External Affairs.
On the 11th May 2009, India submitted to the UN Commission on the limits of the Continental Shelf (CLCS), the country’s first partial submission for an extended continental shelf under the provisions of article 76: technical documentation for a second partial submission under the provisions of the Statement of Understanding has also been provided to the Ministry of External Affairs for submission to the CLCS.
On the 16 August 2010, a six-member delegation led by Dr. Shailesh Nayak, Secretary, MoES made a formal presentation of India’s submission before the Commission on the Limits of the Continental Shelf at the UN Headquarters, New York.
Marine Geophysical Database
During the course of Indian continental shelf Programme as well as other geophysical cruises in the Indian Ocean region, a huge volume of marine geophysical date has been gathered and archived at NCAOR. Considering the immense volume of data and its intrinsic value, a state-of-the-art archival and retrieval facilities of data in a structured database has been established at NCAOR. This Centre was formally commissioned on 11th December 2009 by Dr. Shailesh Nayak, Secretary, MoES. The web based database facilitates customized GIS-based interface for easy retrieval of data from a NAS, queries based on different scientific inputs, and web based input/output interface to facilitate the application to run on internet/intranet with login authentication. The database format is also flexible enough to allow for both vertical and lateral growth.
While the scientific and technical information gathered would admirably serve its primary purpose of delineating the outer limits of India’s continental shelf beyond 200 nautical miles, the surveys have also furnished invaluable data that could form the cornerstone of the country’s planned endeavours in the oceanic realm. Further detailed studies on the data collected are expected to provide the scientific community with answers to some of the long-debated questions as the origin and evolution of such enigmatic features as the 85o East Ridge in the Bay of Bengal, the Laxmi and Laccadive Ridges in the Arabian Sea, the Gulf of Mannar, the offshore extent of the Deccan volcanic, the reasons for the association of gravity lows in the Bay of Bengal with structural highs , the development of the fans vis-a-vis the origin and growth of the Himalayas etc. The studies also open a new vista in the exploration for hydrocarbons in the offshore areas of the continental shelf beyond 200 M. With two of the world’s thickest accumulations of sediments on the seabed (the “Indus Fan” in the Arabian Sea and the “Bengal Fan” in the Bay of 44Bengal) derived from the Himalayas, the data gathered is expected to provide specific insights related to such areas as marine ecosystems, unconventional energy, and offshore mineral resources . An increased understanding of the history and processes of the continental margin around us will also improve the assessment of hazards resulting landslides and tsunamis.
