Bottom sediments of Pulicat Lake, east coast of India

85-92Bottom sediment samples collected from the Pulicat Lake, a coastal lagoon on the east coast of India, have been subjected to mechanical and chemical analysis. Silt clay covers a major part of the lake followed by sand clay, clay sand and sand-silt-clay. The channel portion near the inlet and the wave-active marginal areas of the lake constitute mainly of sand. Phimean size and standard deviation show increasing trends from shore to the relatively quiet central part. The variation in the textural characteristics of the lake sediments is interpreted as resulting from varying degrees of mixing between an earlier deposited sand and modern silt and clay. Organic matter content of the sediments is in general low and the distribution pattern is inversely related to the mean grain size. The peripheral areas of the lake bottom have the least carbonate content (less than 5%). Sand clay and clay type sediments in the central part of the eastern lagoon are rich in carbonate

Sandstones in the Coastal Area Between Visakhapatnam & Bhimunipatnam, East Coast of India

46-48The 2 highly ferruginous sandstone units found are elongate, parallel to the coast line and are unfossiliferous. The sandstones are coarse grained, well sorted and negatively skewed. Textural characters, areal pattern and mineralogical composition suggest that the sandstones have been derived from the eolian red sands and deposited during one of the sea level fluctuations on the east coast of India. The sandstones are considered to be post-pleistocene in age in view of their position above the late Pleistocene red sandy sediments

Analysis of Hindcasting wind waves and swell off Mangalore

21-25SMB method has been used for hindcasting waves and swell off Mangalore, Karnataka, India, during the SW monsoon of 1968 and 1969. Significant wave characteristics, both height and period, predicted by this method compare well with the recorded data. It is found that the fetch is not a continuous one. Two generating areas are encountered (from 74 to 70ᵒ E and 70 to 64ᵒ E). Waves generated between 64 and 70ᵒE play predominant role in forming the significant wave spectrum. During peak monsoon period waves generated beyond 64ᵒE also approach Mangalore Coast with significant periods of 10-12 sec. The effect of refraction especially for waves coming from SW and NW can not be neglected. A bottom friction factor f = 0.05 is found to be suitable for evaluating shallow water wave characteristics at this coast. Statistical relationships for obtaining shallow water significant wave height from deep water wave characteristics are presented

Environmental changes associated with monsoon induced upwelling, off central west coast of India

115-119Coastal upwelling of nutrients during and after the southwest monsoon has been considered to support rich pelagic and demersal fisheries off the west coast of India. Studies indicate, occurrence of coastal upwelling associated with Ekman transport in response to prevailing equatorward winds. High salinity ocean waters of rich nutrient contents were observed at the coast in some locations. However, the effect of upwelling on the surface distribution of properties was reduced to some extent due to coastal runoff which gives the region a patchy distribution of properties