Imprints of Chilika Lake in the offshore region – A geomorphologic evidence
IR@NIO: CSIR-National Institute Of Oceanography, Goa
View Archive Info| Field | Value | |
| Creator |
Subrahmanyam, V.
Murthy, K.S.R. Subrahmanyam, A.S. Rao, K.M. Sarma, K.V.L.N.S. Reddy, N.P.C. Murty, G.P.S. Devi, D.K. |
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| Date |
2006-06-15T09:55:46Z
2006-06-15T09:55:46Z 2006 |
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| Identifier |
Current Science, Vol. 90(9),1180-1182
http://drs.nio.org/drs/handle/2264/120 |
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| Description |
Chilika Lake (Orissa, India) is the largest lagoon in the subcontinent along the east coast of India, situated between latitudes 19 degrees 28’ and 19 degrees 54’ N and longitudes 85 degrees 05’ and 85 degrees 38’ E. In order to study the morphology of the seafloor over the shelf region between Gopalpur and Paradip, bathymetry data was collected along 12 (twelve) coast perpendicular traverses within the water depths of 40-2,300m onboard the Research Vessel Gaveshani by Regional Center, National Institute of Oceanography, Visakhapatnam, Andhra Pradesh, India. The bathymetry profiles along the survey traverses show several channels with varied dimensions in the slope region of the seafloor. Step like terraces in the slope region followed by a V shaped channel of 400 meters deep with a width of 9 km was observed. Further, sediment slumps/topographic highs are noticed in the slope region with dimension varying between 5 and 15 m and a relief of 140 to 400m from the adjacent seafloor. The trend of the bathymetry contours show landward trend in the 50m, 100m, 200m and 500m isobaths resembling arch shape suggesting long and broad channel like feature, which gave an indication of imprints of Chilika Lake in the offshore region. The width of this feature (sickle shaped geomorphic feature) in offshore varies between 62 and 92Km. It is narrow at the mouth of the Chilika Lake and broad towards offshore. The depth of this feature from the adjacent seafloor varies from 60 to 700m. The anatomy of the channel suggests that the turbidity sediments are flowing in a semi-circular manner within the channel. When the muddy sediments are striking the lobe/wall within the channel, they get bounced back which in turn lead to form step like small terraces on the lobe of the channel. The occurrence of terrace like features in the upper slope area off Chilika Lake may also suggest intensive slumping and slope erosion due to direct dumping of sediment when the sea level was at its lowest strandlines along the coast. Contour map indicates converging trend of contours up to northern edge of the sickle shaped feature with high gradient depth pattern, beyond which it is showing diverging trend following the coastline. This high gradient depth pattern and the northern edge of the sickle shaped feature probably falls in the region of the southern boundary of the Mahanadi offshore basin.
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63488 bytes
application/pdf |
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| Language |
en
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| Publisher |
Indian Academy of Sciences
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| Title |
Imprints of Chilika Lake in the offshore region – A geomorphologic evidence
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| Type |
Article
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