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dc.contributor.authorRamana, M.V.
dc.contributor.authorRamprasad, T.
dc.contributor.authorParopkari, A.L.
dc.contributor.authorBorole, D.V.
dc.contributor.authorRao, B.R.
dc.contributor.authorKarisiddaiah, S.M.
dc.contributor.authorDesa, M.
dc.contributor.authorKocherla, M.
dc.contributor.authorJoao, H.M.
dc.contributor.authorLokaBharathi, P.A.
dc.contributor.authorDeSouza, M.J.B.D.
dc.contributor.authorPattan, J.N.
dc.contributor.authorKhadge, N.H.
dc.contributor.authorPrakashBabu, C.
dc.contributor.authorSathe, A.V.
dc.contributor.authorKumar, P.
dc.contributor.authorSethi, A.K.
dc.date.accessioned2009-06-05T09:48:19Z
dc.date.available2009-06-05T09:48:19Z
dc.date.issued2009
dc.identifier.citationGeo-marine letters, vol.29(1); 25-38
dc.identifier.urihttp://drs.nio.org/drs/handle/2264/3359
dc.description.abstractSome main results of multidisciplinary investigations carried out within the framework of the Indian National Gas Hydrate Program in 2002–2003 in the Krishna–Godavari Basin offshore sector, east coast of India are reported, to explore indicators of likely gas hydrate occurrence suggested by preliminary multi-channel seismic reflection data and estimates of gas hydrate stability zone thickness. Swath bathymetry data reveal new evidence of three distinct geomorphic units representing (1) a delta front incised by several narrow valleys and mass flows, (2) a deep fan in the east and (3) a WNW–ESE-trending sedimentary ridge in the south. Deep-tow digital side-scan sonar, multi-frequency chirp sonar, and sub-bottom profiler records indicate several surface and subsurface gas-escape features with a highly resolved stratification within the upper 50 m sedimentary strata. Multi-channel seismic reflection data show the presence of bottom simulating reflections of continuous to discrete character. Textural analyses of 76 gravity cores indicate that the sediments are mostly silty clay. Geochemical analyses reveal decreasing downcore pore water sulphate (SO sub(4) sup(2-)) concentrations (28.7 to <4 mM), increasing downcore methane (CH sub(4)) concentrations (0-20 nM) and relatively high total organic carbon contents (1-2.5%), and microbial analyses a high abundance of microbes in top core sediments and a low abundance of sulphate-reducing bacteria in bottom core sediments. Methane-derived authigenic carbonates were identified in some cores. Combined with evidence of gasescape features in association with bottom simulating reflections, the findings strongly suggest that the physicochemical conditions prevailing in the study area are highly conducive to methane generation and gas hydrate occurrence. Deep drilling from aboard the JOIDES Resolution during 2006 has indeed confirmed the presence of gas hydrate in the Krishna–Godavari Basin offshore.
dc.language.isoen
dc.publisherSpringer
dc.rightsAn edited version of this paper was published by Springer. This paper is for R & D pupose and Copyright [2009] Springer. All efforts have been made to respect the copyright to the best of our knowledge. Inadvertent omissions, if brought to our notice, stand for correction and withdrawal of document from this repository.
dc.subjectgas hydrates
dc.subjectunderwater exploration
dc.subjectoil and gas exploration
dc.subjectseismic data
dc.subjectseismic reflection
dc.subjectmethane
dc.titleMultidisciplinary investigations exploring indicators of gas hydrate occurrence in the Krishna–Godavari Basin offshore, east coast of India
dc.typeJournal Article


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