Sabu,P; Dr.Revichandran,C(Cochin University of Science & Technology, January , 2009)
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Abstract:
The present study
examines the importance of low saline waters and resulting barrier layer
in the dynamics of the ASWP using observational data.The oceanic general circulation models (OGCM) are very useful for
exploring the processes responsible for the ASWP and their variability.
The circulation and thermohaline structure stimulated by an OGCM
changes a lot when the resolution is increased from mesoscale to macro
scale. For a reasonable simulation of the ASWP, we must include the
mesoscale turbulence in numerical models. Especially the SEAS is an
eddy prominent region with a horizontal dimension of 100 to 500 km and
vertical extent of hundred meters. These eddies may have an important
role on the evolution of ASWP, which has not been explored so far.Most of the earlier studies in the SEAS showed that the heat buildup
in the mixed layer during the pre-monsoon (March-May) is primarily
driven by the surface heat flux through the ocean-atmosphere interface,
while the 3-dimensional heat budget of the ML physical processes that are
responsible for the formation of the ASWP are unknown. With this
background the present thesis also examines the relative importance of
mixed layer processes that lead to the formation of warm pool in the
SEAS.
Lasitha, S; Dr.Radhakrishna, M(Cochin University of Science and Technology, September , 2007)
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Abstract:
This work aims to study the variation in subduction
zone geometry along and across the arc and the fault pattern within the subducting
plate. Depth of penetration as well as the dip of the Benioff zone varies considerably
along the arc which corresponds to the curvature of the fold- thrust belt which varies
from concave to convex in different sectors of the arc. The entire arc is divided into 27
segments and depth sections thus prepared are utilized to investigate the average dip
of the Benioff zone in the different parts of the entire arc, penetration depth of the
subducting lithosphere, the subduction zone geometry underlying the trench, the arctrench
gap, etc.The study also
describes how different seismogenic sources are identified in the
region, estimation of moment release rate and deformation pattern. The region is
divided into broad seismogenic belts. Based on these previous studies and seismicity
Pattern, we identified several broad distinct seismogenic belts/sources. These are l)
the Outer arc region consisting of Andaman-Nicobar islands 2) the back-arc Andaman Sea 3)The Sumatran fault zone(SFZ)4)Java onshore region termed as Jave Fault Zone(JFZ)5)Sumatran fore arc silver plate consisting of Mentawai fault(MFZ)6) The offshore java fore arc region 7)The Sunda Strait region.As the Seismicity is variable,it is difficult to demarcate individual seismogenic sources.Hence, we employed a moving window method having a window length of 3—4° and with 50%
overlapping starting from one end to the other. We succeeded in defining 4 sources
each in the Andaman fore arc and Back arc region, 9 such sources (moving windows)
in the Sumatran Fault zone (SFZ), 9 sources in the offshore SFZ region and 7 sources
in the offshore Java region. Because of the low seismicity along JFZ, it is separated
into three seismogenic sources namely West Java, Central Java and East Java. The
Sunda strait is considered as a single seismogenic source.The deformation rates for
each of the seismogenic zones have been computed. A detailed error analysis of
velocity tensors using Monte—Carlo simulation method has been carried out in order
to obtain uncertainties. The eigen values and the respective eigen vectors of the
velocity tensor are computed to analyze the actual deformation pattem for different
zones. The results obtained have been discussed in the light of regional tectonics, and
their implications in terms of geodynamics have been enumerated.ln the light of recent major earthquakes (26th December 2004 and 28th March
2005 events) and the ongoing seismic activity, we have recalculated the variation in
the crustal deformation rates prior and after these earthquakes in Andaman—Sumatra
region including the data up to 2005 and the significant results has been presented.ln this
chapter, the down going lithosphere along the subduction zone is modeled using the
free air gravity data by taking into consideration the thickness of the crustal layer, the
thickness of the subducting slab, sediment thickness, presence of volcanism, the
proximity of the continental crust etc. Here a systematic and detailed gravity
interpretation constrained by seismicity and seismic data in the Andaman arc and the
Andaman Sea region in order to delineate the crustal structure and density heterogeneities a Io nagnd across the arc and its correlation with the seismogenic behaviour is presented.
Description:
Department of Marine Geology & Geophysics,
Cochin University of Science and Technology
Sreedevi, Kutty N; Dr.Damodaran,R; Dr.Rosamma,Philip(Cochin University of Science & Technology, November , 2009)
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Abstract:
The present study provides an account of the occurrence and diversity of
marine yeasts in the slope sediments of Arabian Sea and Bay of Bengal. It also
gives a clear idea about the role of yeasts in the benthic realm of marine
ecosystem. The lipolytic potential of the organisms indicate the presence of rich
lipid moieties in the study area. The isolates, Candida sp. SD 302 and Pichia
guilliermondii SD 337 were proved to have potential oil degrading property and
can be employed as bioremediators of oil spill after further characterization. The
black yeasts isolated during the study area were found to have high commercial
value by virtue of the by-products obtained from them. The melanin and the
melanin degrading enzyme extracted from these organisms are potential
bioactive materials for application in cosmetology.
Description:
Department of Marine Biology, Microbiology and Biochemistry, Cochin University of Science and Technology
Sona, A; Dr. Mukundan, M K(Central Institute of Fisheries Technology, July , 2004)
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Abstract:
In the attempt to find out catalytic potency and properties of the endoglucanase
of green mussel, it could be highlighted that the enzyme is efficient in degrading
carboxymethylcellulose to reducing sugars. The immobilized enzyme will find
applications in the food industry, paper and pulp industry, wood preservation,
alcohol and pharmaceutical industry.The purification method employed i.e. Sephadex G100 chromatography
employing affinity and exclusion principles simplify the purification procedure.Addition of Mg2+ and Co2+ at 10mM concentrations enhances endoglucanase
activity of green mussel.The immobilized endoglucanase can be used for deinking mixed office waste
paper. The endoglucanase if supplemented with exoglucanase and B-glucosidase
under appropriate conditions would help in the recycling of paper.
Sabu, S; Boopendranath, M R(Cochin University of Science & Technology, August , 2008)
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Abstract:
Trawling, though an efficient method of fishing, is known to be one of the most non-selective methods of fish capture. The bulk of the wild caught penaeid shrimps landed in India are caught by trawling.In addition to shrimps, the trawler fleet also catches considerable amount of non-shrimp resources. The term bycatch means that portion of the catch other than target species caught while fishing, which are either retained or discarded. Bycatch discards is a serious problem leading to the depletion of the resources and negative impacts on biodiversity. In order to minimize this problem, trawling has to be made more selective by incorporating Bycatch Reduction Devices (BRDs). There are several advantages in using BRDs in shrimp trawling. BRDs reduce the negative impacts of shrimp trawling on marine community. Fishers could benefit economically from higher catch value due to improved catch quality, shorter sorting time, lower fuel costs, and longer tow duration. Adoption of BRDs by fishers would forestall criticism by conservation groups against trawling.
Description:
Faculty of Marine Sciences
COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY
COCHIN-682 022