000393   Lierheimer L J;Banse K (U. S. Fish and Wildlife Service, Office of International Affairs, Divi, , 4401 North Fairfax Drive, Arlington, VA 22046) : Seasonal and interannual variability of phytoplankton pigment in the laccadive (Lakshadweep) sea as observed by the coastal zone color scanner. Proc Indian Acad Sci-Earth Planet Sci 2002, 111(2), 163-85.

Based on Coastal Zone Color Scanner data from November 1978 through Secember 1981, the seasonal cycle of phytoplankton pigment in the upper part of the euphotic zone is established for the offshore Laccadive Sea. Year-round, the pigment content is low and the seasonal range is small, following the pattern of the nutrient-poor Arabian Sea to the west. Apparently, indigenous phytoplankton blooms are absent. July and August, however, were poorly studied because of cloud cover. Interannual differences during the northeaset monsoon and the spring intermonsoon periods are minor. The abundant phytoplankton caused by the upwelling off India during the southwest monson remains essentially restricted to the shelf, but there are occasional large, zonal outbreaks into the Laccadive Sea, as well as others advected to the south of India. Visual inspection of the raw CZCS scenes for June through November 1982-1985, with almost no data unitl August or even Septemper, shows such outbreaks of pigment-rich water to be common. Inspection of monthly Sea WiFS images for 1997 through part of 2001 cponfirms the absence of indigenous phytoplankton blooms.

9 illus, 1 table, 54 ref

000392   Krishna N D R;Maji A K;Krishna Murthy Y V N; Rao B S P (National Bureau of Soil Survey and Land Use Planning, , Amravati Road, Nagpur) : Remote sensing and geographical information system for canopy cover mapping. J Indian Soc Remote Sens 2001, 29(3), 107-13.

Availability of remote sensing data from earth observation satellites has made it convenient to map and monitor land use/land cover at regional to local scales. A land cover map is very critical for a various planning activities including watershed planning. The spectral and spatial resolutions are major constraints for mapping the crop resources at micro-level. The cropping pattern zones have been mapped using the false color composite, physiography, irrigation and toposheets. The IRS LISS_III data is classified into various categories depending on spectral reflectance from crop canopy and are overlaid on cropping zones map. The re-classified resultant map provides land use/land cover information including dominant cropping systems. The canopy cover is estimated monthly considering the crop calendar for the area.

4 illus, 1 table, 6 ref

000391   Karia J P;Porwal M C;Roy P S;Sandhya G (Dep of Botany, M S University of Baroda, Vadodara-390 001) : Forest change detection in Kalarani Round, Vadodara, Gujarat - a remote sensing and GIS appraoch. J Indian Soc Remote Sens 2001, 29(3), 129-35.

Studies on spatial distribution of the different forests during 1970 to 1999 using integrated remote sensing and GIS techniques reveal that area under forests in the Kalarani Round, is progressively reducing with the time. In 1970 forest area was found to be 22.75 sq km, in 1989 it was 15.34 sq km and in 1999 it was only 12.93 sq km. Thus, there is considerable loss in the tree cover from 1989 to 1999. Jhanpa and Kalarani R.F. are the example of this. Ground surveys indicate that the majority of the loss is caused by heavy grazing pressure there by decreasing regeneration of vegetation. If suitable measures are not taken whole area may be converted into wasteland in due course of time. Another reason for the forest loss, could be land encroachments by villagers for their overwhelming needs. Karali R.F. is not much disturbed apart from the plantation raised in the foothills. Outside the reserve forest boundary, the change was observed dur to construction of Narmada Sagar canal

3 illus, 1 table, 20 ref

000390   Jai Sankar G;Rao M J;Rao B S P;Jugran D K (Dep of Geo-engineering, College of Engineering, Andhra University, Visakhapatnam-530 003) : Hydromorphogeology and remote sensing applications for groundwater exploration in Agnigundala mineralised belt, Andhra Pradesh, India. J Indian Soc Remote Sens 2001, 29(3), 165-74.

Hydromorphogeological studies have been carried out around Agnigundala mineralised belt (longitude 70°.39' - 16°.51' and latitude 16°.2' - 16°.15°') using remote sensing IRS-1B and SPOT data for ground water exploration. Based on erosional and depositional characters of various geomorphic units like Hills (Structural and denudational) Pediment. Buried pediment, plains and valley fills have been identified in various lithologies like granite, granite gneiss, biotite schist, phyllite, quartzite and dolomite. The acclamations of individual geomorphic units through visual interpretation are verified from field data. The groundwater potentials of the individual geomorphologic units have been evaluated to obtain a complete hydrogeological picture of the area. The field data have further helped in quantifying various geomorphological units with reference to their potential for ground water occurrence.

2 illus, 1 table, 17 ref

000389   Jagtap T G;Naik S;Nagle V L (National Institute of Oceanography, , Dona-Paula, Goa-403 004) : Assessment of coastal wetland resources of central west coast, India, using LANDSAT data. J Indian Soc Remote Sens 2001, 29(3), 143-50.

Part of central west coast (Maharashtra and Goa) of India has been classified and quantified for coastal wetlands using LANDSAT data of 1985-86. The classification accuracy of the maps and area estimates, achieved was 84% at 90% confidence level and the planimetric accuracy at 1:2,50,000 scale was 0.3 mm. The total coastal wetland areas in Maharashtra and Goa, have been estimated to be 1567 and 115 km², respectively. The estuarine and backwater regions contribute 44.6% of the wetland, followed by open mudflats (32%), mangroves (8.8%) and beach/spit (7.8%). Mangroves comprised of 17 species and are dominanted by Rhizophora mucronata Avicennia officinalis. A. marina Sonneratia alba Excoecaria agallocha and Acanthus ilicifolius. The sand-dune flora comprised of 63 species while rocky intertidal regions harboured <62> 100 species of marine algae. Erosional changes have been noticed to be predominant along the Maharashtra coast while progradation of beaches is noticed in Goa.

2 illus, 1 table, 15 ref

000388   Gundu Rao T K;Rajendran C P;John B (NO, R.S.I.C., Indian Institute of Technology, Powai, Mumbai-400 076) : Electron spin resonance dating of fault gouge from desamangalam, Kerala: evidence for quaternary movement in palghat gap shear zone. Proc Indian Acad Sci-Earth Planet Sci 2002, 111(2), 103-13.

The field investigations in th eepicentral area of the 1994 Wadakkancheri (Desamangalam), Kerala, earthquake (M 4.3) indicate subtle, but clearly recognizable expressions of geologically recent fault zone, consisting of fracture sets showing brittle displacement and a gouge zone. The fracture zone confines to the crystalline basement, and is spatially coincident with the elongation of the isoseismals of the 1994 mainshock and a 10-km-long WNW-ESE trending topographic lineament. The preliminary results from the electron spin resonance (ESR) dating on the quartz grains from the fault gouge indicate that the last major faulting in this site occurred 430±43 ka ago. The experiments on different grain sizes of quartz from the gouge showed consistent decrease in age to a plateau of low values, indicating that ESR signals in finer grains were completely zeroed at the time of faulting due to frictional heat. The results show a relatively young age for displacement on the fault that occurs within a Precambrian shear zone. Discrete reactivated faults in such areas may be characterized by low degree of activity, but considering the ESR age of the last significant faulting event, the structure at Desamangalam may be categorized as a potentially active fault capable of generating moderate earthquakes, separated by very long periods of quiescence.

6 illus, 1 table, 30 ref

000387   Ghosh P;BhattacharyaS K;Dayal A M;Trivedi J R;Ebihara M;Sarin M M;Chakrabarti A (NO, , hysical Research laboratory) : Trace element and isotopic studies of permo-carboniferous carbonate nodules from talchir sediments of peninsular India: environmental and provenance implications. Proc Indian Acad Sci-Earth Planet Sci 2002, 111(2), 87-101.

Syngenetic carbonate nodules constitute an interesting feature of the glaciogene sediments of various Talchir basins in peninsular India. Petrographic, cathodoluminescence and sedimentary results suggest that many of these nodules contain primary carbonate precipitates whose geochemical signatures can be used for determining environemt of deposition and provenance of the sediments and drainage source. Several nodules were collected from Gondwana basins of east-central India and analyzed for stable carbn and oxygen isotope ratios, REE and trace element composition, and Sr isotope ratio. The mean δ¹⁸O and δ¹³C values of the calcites in the nodules are - 19.5δ and-9.7δ (w.r.t. PDB) respectively suggesting a freshwater environment (probably lacustrine) for formation of these objects. Trace element ratios (Eu/Eu and La/Yb) of the nodule samples show that the source of the sediments in the Damodar valley basin was the granites, gneisses and intrusives in the Chotanagpur region. The sediments in the Mahanadi valley were derived from granulites, charnockites and granites of the eastern ghat region. The Sr concentration of the carbonate phase of the nodules is low, ranging from 10-60 ng/g. The ⁸⁷Sr/⁸⁶Sr ratios of the samples from the west Bokaro basin and Ramgarh basin vary from 0.735 to 0.748 (mean; 0.739) and from 0.726 to 0.733 (Mean: 0.730) respectively....

6 illus, 3 tables, 49 ref

000386   Ganesha Raj K;Paul M A;Hegde V S;NIjagunappa R (EOS/NNRMS, ISRO Hq, , Antariksh Bhavan, New BEL Road, Bangalore-560 094) : Lineaments and seismicity of Kerala - a remote sensing based analysis. J Indian Soc Remote Sens 2001, 29(4), 203-11.

Seismically active lineaments of Kerala State were identified by correlating the lineaments mapped using IRS LISS-I data with the earthquake occurrences. There are 31 earthquake incidences in Kerala since 1821, out of which 22 are falling on/close to 9 major lineaments/faults (length more than 20 km) indicating the possible correlation between lineaments/faults and earthquakes. It was observed that the earthquake occurrences are mostly associated with the NNW-SSR to NW-SE trending lineaments (6 out of 9 lineaments), which are considered to be formed sympathetic to the West Coast Fault. Hence, there is a need to monitor these seismically active lineaments using advanced techniques such as GPS, SAR Interferometry etc. for better understanding of the influence of these lineaments on the seismic activities of Kerala.

2 illus, 2 tables, 27 ref

000385   Dutta S;Patel N K;Srivastava S K (Agricultural Resources group, Space Applications Centre, Ahmedabad-380 015) : District wise yield models of rice in Bihar based on water requirement and meteorological data. J Indian Soc Remote Sens 2001, 29(3), 175-82.

Pre-harvest crop production forecast has been successfully provided by remote sensing technique. However, the probability to get cloud-free optical remote sensing data during kharif season is poor. Microwave data having the capability to penetrate cloud is used in the absence of cloud free optical remote sensing data. Yield models in brand band frequency range are in development stage. Meteorological yield models are developed and predicted yield is combined with area estimated by remote sensing data to provide rice production forecast. Describes the methodology adopted for improving the predictability of rice yield before harvest of the crop in Bihar province by taking into consideration meteorological parameters during its growth cycle upto October. Models developed using fortnightly meteorological data have been found to give reasonably fair indications of expected yield of rice in advance of harvest. The yield predictions have been made based on meteorological data and effective rainfall based on water requirement calculations representing a group of districts under similar agro-climatic zones, which could be further improved by incorporating meteorological data of individual districts within each group.

1 illus, 1 table, 20 ref

000384   Durbude D G;Purandara B K;Sharma A (Hard Rock Regional Centre, National Institute of Hydrology, Belgaum-590 001) : Estimation of surface runoff potential of a watershed in semi-arid environment. J Indian Soc Remote Sens 2001, 16(1-2), 47-58.

Accurate assessment of run-off through aerial rainfall is a basic concept in most of the rainfall-runoff models, particularly conceptual models which emphasis a complete water balance. The run-off measurements by gauging can only be regarded as an index of rainfall and restrict our ability to successfully model the rainfall-runoff process. To overcome some of these problems, remote sensing satellite data are of immense use, particularly in mountainous and desert areas. A typical watershed from a drought hit Banswara district of Rajasthan has been analysed using IRS-1B-LISS II satellite imagery for estimating the run-off potential under different geomorphic set-up. The run-off potential was estimation using SCS method based on the satellite data in conjunction with ground truth information collected during field visit. The results indicated that the soil and water conservation measures in the watershed would improve the existing water potential and storage capacity of the study area. Based on the study eight check dams and five lift irrigation schemes are proposed.

4 illus, 9 tables, 5 ref

000383   Doi R D (Dep Geography, University of Rajasthan, Jaipur-302 004) : Vegetational response of rainfall in Rajasthan using AVHRR imagery. J Indian Soc Remote Sens 2001, 29(4), 213-24.

Demonstrates the suitability of NOAA-AVHRR imagery for monitoring vegetal cover. Climate is recognized as the most important control on natural vegetaion. However, spatial and seasonal changes in land cover are dependent on several factors including the crop species, soil hydrology, grazing conditions, harvest timing and above all on the frequency and amount of rainfall. The analysis is based on six maximum value composite (MVC) NDVI images with a spatial resolution of approximately 5.5 km. An attempt has also been made to examine the serial relationship between the NDVI and the rainfall occurrences at different stations. `Thar Derert' is clearly visible in the images of summer months. A transitional zone is situated between the arid and semi-arid areas along the western fringe of the Aravalli Range. The elimination of time lag in vegetational response of rainfall indicates expected positive relationship between vegetal cover and rainfall.

3 illus, 4 tables, 12 ref

000382   Dash P;Gottsche F M;Olesen F S;Fischer H (Institute for Meteorology and Climate Research, Forschungszentrum Karlsruhe/Karlsruhe University, Postfach 3640, D-76021 Karlsruhe, Germany) : Retrieval of land surface temperature and emissivity from satellite data: physics, theoretical limitations and current methods. J Indian Soc Remote Sens 2001, 16(1-2), 23-30.

Remote sensing from satellites is the only means to obtain land surface temperature (LST) and emissivity on a larger scale. LST has many applications, e.g., in radiation budget experiments and global warming, and desertification studies. Over the last decades, substantial amount of research was dedicated towards extracting LST and emissivity from surface-leaving radiance and de-coupling the two from each other. Provides physical basis, discusses theoretical limitations, and gives an overview of the current methods for space-borne passive sensors operating in the infrared range, e.g., NOAA-AVHRR, Meteosat, ERS-ATSR, TERRA-MODIS, and TERRA-ASTER. Atmospheric effects on estimated LST are described and atmospheric-correction using a radiative transfer model (RTM) is explained. The methods discussed are the single channel method, the split window techniques (SWTs), and the multi-angle method.

3 illus, 35 ref

000381   Das L K;Agarwal B N P (Geophys Div, CHQ, Geological Survey of India, 27 J.L. Nehru Road, Calcutta-700 016) : Evolution of the Singhbhum craton: a geophysical perspective. Indian Miner 2001, 55(3-4), 143-70.

The evolutionary history of Singhbhum craton dates back to 33.3-3.4 Ga when the Archaean granite-greenstone nucleus was formed. Subsequently, imprints of several younger orogenesis are seen over the craton which are conspicuous in the formation of different sedimentary basins, igneous activities including outpouring of volcanic rocks and many phases of granitic intrusions, till it culminated in the Singhbhum Orogenic Cycle (850 Ma). Studied the Craton using the gravity and deep resistivity data. From the analyses of the above data set and constrained by the published geochronological and structural findings, tried to project an evolutionary model for the Singhbhum Craton.

18 illus, 1 table, 45 ref

000380   Chakraborty D;Dutta D;Chandrasekharan H (Water Technology Centre, Indian Agricultural Research Institute, New Delhi-110 012) : Land use indicators of a watershed in arid region, Western Rajasthan using remote sensing and GIS. J Indian Soc Remote Sens 2001, 29(3), 115-28.

The vegetation dynamics and land use/land cover types of Birantiya Kalan watershed located in the arid tracts of western Rajasthan have been characterized and evaluated using Remote Sensing and Geographical Information System (GIS). The watershed under study falls in the transitional plain of Luni Basin and is characterized by Aravali ranges in the eastern half and vast alluvial plains in the west. The land use/land cover types, as identified are cropland, fallow, forest, land with scrub, land without scrub, sandy area and the water body. Land with scrub occupied maximum area (39% area of the watershed) in 1996 in place of crop land which was dominant (43% of total area) in the year 1988. During eight years period, seasonal fallow land increased significantly and the areal extent of water body decreased to almost half. Vegetation vigour types have been classified into very poor, poor, moderate, good and very good categories. Moderate vigour type reduced from 62 to 27% and poor type increased from 34 to 68% during the period 1988 to 1996. Other vegetation vigour type have not shown any significant chagnes. To quantify the changes over the years in both vegetation and land use/land cover, weightages have been given to each type and composite values of both vegetation vigour and land use types for 1996 and 1988 have been calculated.

8 illus, 2 tables, 8 ref

000379   Chakrabarti C;Chattopadhyay G S (NO, Geological Survey of India, Kolkata) : Quaternary geology of south Ganga plain in Bihar. Indian Miner 2001, 55(3-4), 133-42.

The south Ganga alluvial plain in Bihar is a linear tract restricted by te Ganga River in the north, Rajmahal hills to the east and Chhotanagpur plateau to the south. The tract is, however, divided into three broad physiographic-cum-geomorphic domains as Chandan - Badua basin, Pun Pun - Phalgu - Kiul basin and Con basin. The Chandan - Badua basin lies on the partially buried Munger - Saharsha basement ridge with relatively shallow depth to basement. A three-fold classification of the overlying Quaternary sediments has been firmly established for this basin. The Pun Pun-Phalgu-Kiul basin lies on a downsunken basement block bounded to the west b the East Patna fault and to east by the western edge of the partially buried Munger - Saharsha ridge. A four-fold classification has been proposed for the area. The Son basin in Bihar is a large tract extending from Uttar Pradesh border (to the west) to south of Patna City to the east. The eastern boundary, therefore, roughly coincides with the East Patna basement fault. A multiple-fold classification has been depicted for the area.

1 illus, 6 tables, 15 ref

000378   Bose Mihir K;Maitra M;Das D;Ray J (Department of Geology, Presidency College, Kolkata-700 073) : Structure and petrology of the mafic granulites and associated rocks of the Kanjamalai complex Salem district, Tamil Nadu. Indian Miner 2001, 55(3-4), 119-32.

Petrological details and structural framework of the kanjamalai complex (11°37' N : 78°05' E) comprising mafic granulite interlayered with BMQ and associated granitoid bands have been brought out. The Kanjamalai complex, Salem district, records a history of polyphase deformation manifested through F₁, F₂ and F₃ folds. F₁ folds are tight rootless types (present only in BMQ). F₂, folds with E-W axial trend are represented by feebly non-cylindrical open folds and develop pervasive planar structure. F₃ is cross-fold with N-S-trending, vertical axial plane with axial culmination. The board structural framework and outcrop pattern of the Kanjamalai complex are controlled by superposition of F₂ and F₃, cross-folding. The major litho-member of the complex viz. mafic granulite reveals two distinct petrographic groups distinguished by the development of garnet or otherwise: i) garnetiferous type with dominant clinopyroxene (salite) and trace of hypersthene and ii) non-garnetiferous type characterised by abundant orthopyroxene and pargasitic amphibole. Andesinic plagioclase is ubiquitous in both the types. Locally pyroxene hornblendite has developed as a variant of non-garnetiferous mafic band. Discrete lensoid intrusions of tonalite and granite components of the Kanjamalai complex also record the imprint of deformation. Mineral chemistry for both the granulite types has been presented.

4 illus, 8 tables, 32 ref

000377   Bisht B S;Kothyari B P (G B Pant Institute of Himalayan Environment and Development, , Kosi-Katarmal, Almora-263 643) : Land-cover change analysis of Garur Ganga watershed using GIS/remote sensing technique. J Indian Soc Remote Sens 2001, 29(3), 137-41.

Land-use change and land-cover classes in Garur Ganga watershed of Bageshwar district in Uttranchal State during the periods 1963-1996 and 1986-1996 were analyzed through Survey of India Topographical Sheet and visual interpretation of LANDSAT 5 TM image bands 2, 3 and 4 using Geographical Information system (GIS). The detailed analysis have revealed that the area under agriculture and settlement increased from 34.98 to 42.34%, whereas the forest and barren land show a declinng trend. Expansion of agriculture land and builtup areas have been found to be maximum in the 1200-1600 m elevation zone with 7-14° slope class. The loss of vegetation cover has been estimated to be 5.07% between 1963-1996 and 0.81% between 1986-1996.

2 illus, 1 table, 7 ref

000376   Bhattacharya D K;Barla V C;Singh B (Postgraduate Department of Geology, Ranchi College, Ranchi-834 008) : Geochemistry and petrogenesis of granite gneisses, southeast of daltonganj, Palamau district, Jharkhand. Indian Miner 2001, 55(3-4), 219-26.

The field, mineralogical and geochemical characteristics of granite gneisses occurring south of Daltonganj are consistent with S-type nature of the granitoids. High value of A/CNK (>1.1) and high proportion of normative corundum suggest peraluminous source for these rocks. Major- and trace-element geochemistry suggest a syn-collisional tectonic regime for these rocks.

6 illus, 3 tables, 12 ref

000375   Bhan S K (NO, National Remote Sensing Agency, Hyderabad-500 031) : Study of floods in West Bengal during september, 2000 using Indian remote sensing satellite data. J Indian Soc Remote Sens 2001, 16(1-2), 1-2.

3 illus, 1 table

000374   Bawaiskar S M;Mujumdar V R;Singh S S (NO, Indian Institute of Tropical Meteorology, Pune-411 008) : Momentum transport of wave zero during march: a possible predictor for the Indian summer monsoon. Proc Indian Acad Sci-Earth Planet Sci 2002, 111(2), 153-62.

Analysis of monthly momentum transport of zonal waves at 850 hPa for the period 1979 to 1993, between 30°S and 30°N for January to April, using zonal (u) and meridional (v) components of wind taken from the ECMWF reanalysis field, shows a positive correlation (1° level of significance) between the Indian summer monsoon rainfall (June through September) and the momentum transport of wave zero TM (0) over latitudinal belt between 25°S and 5°N (LB) during March. Northward (Southward) TM(0) observed in March over LB subsequently leads to a good (drought) monsoon season over India which is found to be true even when the year is marked with th eEl-Nino event. Similarly a strong westerly zoane in the ndian Ocean during March, indicates a good monsoon season for the country, even if the year is marked with El-Nino. The study thus sugests two predictors, TM(0) over LB and the strength of westerly zone in the Indian Ocean during March.

7 illus, 1 table, 16 ref

000373   Anil Kumar;Sarvajit Singh;Jagdish Singh (Dept of Mathematics, Maharshi Dayanand University, Rohtak-124 001) : Static deformation of two welded monoclinic elastic half-spaces due to a long inclined strike-slip fault. Proc Indian Acad Sci-Earth Planet Sci 2002, 111(2), 125-31.

Static deformation of two monoclinic elastic half-spaces in welded contact due to a long inclined strike-slip fault situated in one of the half-spaces is studied analytically and numerically. Closed form algebraic expressions for the displacement at any point of the medium are obtained. The variation of the displacement at the interface with the horizontal distance from the fault is studied. The effect of anisotropy on the displacement field is examined. It is found that while the anisotropy of the source half-space has a significant effect on the displacement at the interface, the anisotropy of the other half-space has only a marginala effect.

3 illus, 9 ref

000372   Anbazhagan S;Saranathan E (Dep of Earth Sciences, Indian Institute of Technology, Bombay, Mumbai-400 076) : Structure and its impact in Uthangarai and Thirthamalai region, Tamil Nadu, India using remote sensing technique. J Indian Soc Remote Sens 2001, 29(4), 187-95.

The Uthangarai-Thirthamalai region in Dharmapuri district is a typical Precambrian tract in Tamil Nadu. IRS-1C satellite imagery was used for interpreting folds, faults, fractures and lineaments, in this region. As interpreted from the satellite imagery, there are five major structural domains, which control the Ponnaiyar, Pambar, Vaniyar and Kovilar river courses and other drainage pattern in this region. Presence of fault rock, epidotization and sympathetic fractures along such folds and faults reveals the intensity of tectonism in this sector. The interpreted lineaments have been classified into five major groups on the basis of their geometry and orientation. From the rose diagram, it is inferred that the NNW-SSE trending lineaments fall in the major frequency domain. The springs observed near Hanumanthirtham and Thirthamalai region could be structurally originated. The geomorphology interpreted from the satellite data has shown significant morphological expression folds, faults and lineaments. The geophysical data have been analysed and correlated with intensity of weathering by fractures and lineaments.

5 illus, 16 ref

000371   Adhikari S;Biswas U K;Biswas L R (NO, RIL - CBM, 103/106 Naroda Industrial Estate, Ahmedabad-382 330) : Anomalous heat flow in Sohagpur basin and its influence on coal-rank character. Indian Miner 2001, 55(3-4), 209-18.

Heat-flow values were calculated from the study of thermal conductivity of different litho-units from borehole cores together with the data on thermal logging. The data clearly show a steep rise of heat flow values from 24-27 mW/m² in the downthrown side of the above fault. The granite basement of Sohagpur Gondwana basin must be responsible for the generation of shallow crustal heat due to decay of radioisotopes. he sporadic occurrences of K-rich partially melted granitic enclaves within the basic feeder dykes intruding the Gondwana sediments, possibly indicate presence of such potash-rich granite in the basement rock. These potash rich rocks are possibly the source of higher radiogenic heat. The combined effects of rapid deposition of thick pile of sediments, thin Talchir strata and presence of thick cover of low conductive shale/clay in the downthrown side of Bamhani-Chilpa fault might have resulted in higher heat flow that has enhanced the rank of Barakar coal in this part. Shallow sedimentary cover together with thicker Talchir strata down below and deeper weathering of the Barakar due to periodic upliftment might have decreased the conductive heat flow in the upthrown segment of the above fault.

3 illus, 2 tables, 19 ref

021609   Vinod Kumar (Meteorological Officer, C S I Airport, Mumbai-400 099) : Forecasting heavy rainfall over Mumbai. Proc TROPMET Natl Symp 2001, (NULL), 526-30.

Mumbai experiences a few spells of heavy rainfall during South- West monsoon season, when the cross equatorial flow is strong. Due point deepressions (DPD) above 500 hPa pressure height (<60>=5), south-westerly to westerly components (1900 to 2900), or veering/backing of the winds at least from 030 to 150 FIL (Flight level 030 = 3000 feet) and freezing level (5100 - 5900 GPM) quite significantly reveal about the severe weather conditions likely to hit the station in the next 24 hours.

2 tables, 3 ref

021608   Vashistha R D;Balachandran S;Muthuramalingam E;Dikshit S K (Meteorological Office, , Pune) : Sampling effect on estimation of extremes from AWS data. Proc TROPMET Natl Symp 2001, (NULL), 384-8.

In the signal processing of AWS data, sampling plays important role in representation of the significant changes in atmospheric variable measured. Care must be taken in samples that are to be used in estimating extremes of fluctuations. IMD recently deployed new Automatic weather systems using stat-of-the art technology in the field. These systems take observations at hourly interval. The daily maximum/minimum temperature retrieved from hourly records from a field AWS at Pune are compared with that those from conventional methods and the implications of sampling interval in the estimation of such extremes are discussed.

@ illus, 1 table, 3 ref

021607   Valsangkar A B (NO, National Institute of Oceanography, Dona Paula, Goa-403 004) : Implications of post-disturbance studies on the grain size of the sediments from the Central Indian Basin. Curr Sci 2001, 81(10), 1365-73.

Indian Deep-Sea Environment Experiment (INDEX) was conducted by simulating benthic disturbance and resuspension of the sediments in 3 km x 200 m narrow strip at 5300 m water depth in the Central Indian Basin (CIB). Using the conventional coring methods, pre- and post-disturbance data have been compared to predict the probable direction of the plume movement on the seabed. Studies on 84 subsections of 10 box cores show that the disturbance at places was effective up to 25 cm depth. Post-disturbed samples collected from the pre-disturbed locations show an increase of 10 to 27% silt and clay, and indicate that they were the major component of the plume. It has been shown that for such studies the silt and clay can be used as effective indicators of the plume movement. The studies revealed that the plume has migrated at least up to 2 km in the south-west direction and 1 km south of the disturbed zone (DZ). Increase in the surface clay content is ascribed to mixing of the sediments from deeper sections due to the benthic disturbance.

12 illus, 19 ref

021606   Umamaheswar K;Sharma U P;Zakaulla S;Basu H; Thomas A M;Azam Ali M (Atomic Minerals Directorate for Exploration and Research, Department o, , Nagarbhavi, Bangalore-560 072) : Occurrence of gold in association with uranium in Gulcheru quartzite of Cuddapah basin, Gandi-Rachakuntapalle area, Cuddapah district, Andhra Pradesh. Curr Sci 2001, 81(7), 754-6.

1 illus, 1 table, 7 ref

021605   Uberoi C (Department of Mathematics, Indian Institute of Sciences, Bangalore-560 012) : Role of space science in space weather specification: an illustration with auroral studies. Curr Sci 2001, 81(7), 760-67.

Space weather predictions and forecasts are now understood to be essential for protection of both the ground-based and space-based technical systems from their hazardous effects. An attempt is made to point out the importance of the role of space science community in the starting of a National Space Weather Service, by exemplifying the specifications made about the ionospheric conductivity for the recent auroral studies.

11 illus, 10 ref

021604   Trivedi D K;Sanjay J;Singh S S (NO, Indian Institution of Tropical Meteorology, Pune-8) : Tropical cyclone prediction using a high resolution mesoscale model. Proc TROPMET Natl Symp 2001, (NULL), 294-300.

A very high resolution Penn State University/National Center for Atmospheric Research Mesoscale Model (MM5) has been used to simulate the Super Cyclonic Storm of Orissa (1999). The resolutions of the operational analysis systems and pancity of data over the tropical oceans result in severe deficiencies in the representation of tropical cyclones in the analysis. A synthetic vortex generated using some observed parameters for this cyclone and empirical relation has been analysed to improve the initial condition to the model. Four dimensional data assimilation is performed. The enhancement of the initial condition through the use of the synthetic vortex shows considerable improvement in the track forecast. The model has sucessfully simulated the typical tropical cyclone characteristics such as asymmetries in the wind field and stronger gradient in the wind field between the centre and maximum wind region. It is seen that without four dimensional date assimilation the cyclone's intensity is reduced during the initial hours of model forecast.

3 illus, 6 ref

021603   Srivastava A K;Manik S R;Patil G V;Gawande R R (Department of Geology, Amravati University, Amravati-444 602) : Record of genus Hausmannia dunker from the upper Gondwana of Bairam-Belkher area, Amravati district, Maharashtra and Betul district, Madhya Pradesh. Curr Sci 2001, 81(7), 756-57.

1 illus, 14 ref

021602   Singh S L;Singh J (Telecommunication Division, DGMs Office Lodi Road, New Delhi-110 003) : A radar and satellite study of squall lines over Ranchi airfield. Proc TROPMET Natl Symp 2001, (NULL), 408-14.

Three squall lines which originated over northwest sector of Ranchi airfield on March 23, 1998, May 11 and 19, 1999 respectively were tracked by EEC X-band Storm Detection Radar installed at Meteorological Office Ranchi Airport. The squall lines were tracked at frequent intervals. It was observed that when the squall lines were west of Ranchi, they had generally northeast-southwest orientation; when they approached Ranchi Airfield they started rotating anticlockwise; after crossing Ranchi airfield, the orientation was more or less north-south. An attempt has been made to ascertain the cause of the genesis of the systems. Visible and IR pictures received from INSAT-ID satellite were studied in conjunction with meteorological data of northeast India to have a better understanding of weather associated with the squall lines.

4 illus, 1 table, 6 ref

021601   Singh A P (National Geophysical Research Institute, , Uppal Road, Hyderabad-500 007) : Impact of Deccan volcanism on deep crustal structure along western part of Indian mainland and adjoining Arabian Sea. Curr Sci 2002, 82(3), 316-25.

To understand the magmatic processes originating in the deep mantle and their impact on the lower crustal level, the conspicuous gravity anomalies observed over the western part of Indian mainland and contiguous Arabian sea were modelled, integrating the available seismic information. The unified 2D and subsequent 3D density modelling of the Narmada-Tapti region suggests a 15-20 km thick high-density (3.02 g cm^-3) accreted igneous layer at the base of the crust. The thickness of this layer varies from about 8 km near Multai to about 16 km beneath the central part and about 24 km beneath Navsari in the westernmost part of the Narmada-Tapti region. Similarly, a 7-11 km thick accreted igneous layer characterizes the Eastern Basin, including the Laxmi Ridge (LR) in the northeastern Arabian Sea. Thickness of this layer varies from about 4 km beneath the northwestern part to about 11 km beneath the central part of the LR. The extension of this layer towards the southeast and ultimate connection with the Chagos-Laccadive Ridge makes the western boundary of the magmatic crustal accretion along the west coast of India. The Konkan Coast, further down south, is also characterized by a ca. 3 km thick and about 40 km wide accreted igneous layer at the base of the crust along the coastline. It is suggested that this widespreading magmatic underplating along the western part of Indian Land mass and adjoining Arabian Sea is the imprint of the Deccan magmatism.

11 illus, 51 ref

021600   Simon A;Nair V G;Joseph P V (Department of Atmospheric Sciences, Cochin University of Science and Technology, Cochin-10) : Intra-seasonal oscillation in Kerala rainfall. Proc TROPMET Natl Symp 2001, (NULL), 166-73.

Time series of spatial averages of daily rainfall of South and North Kerala (using data of a large number of rain-gauge stations) during the southwest monsoon season (128 days from 29 May to 3 October) of the 80 years (1901-1980) has been analysed in this study. The technique of Wavelet Transform was used to study the low frequency intra-seasonal oscillations in rainfall of south and north Kerala of periods in the range 20 to 100 days. The resolved periods correspond to 23, 27, 32, 38, 45, 54, 64, 76, and 91 days. It is found that there is considerable interannual variability for the period of the intra-seasonal oscillation. About 20 percent of the years have two periods in this range simultaneously. Both in south and north Kerala, about two third of the periods are in the range 23 to 45 days. There is no year with periods of 54, 76 and 91 days. About a third of the resolved periods are of 64 days.

4 illus, 2 tables, 7 ref

021599   Sijikumar S;Joseph P V (Department of Atmospheric Sciences, Cochin University of Science and Technology, Fine Arts Avenue, Cochin-682 016) : Relation between convective heating of atmosphere and monsoon low level jet-stream over peninsular India. Proc TROPMET Natl Symp 2001, (NULL), 150-5.

Examines the relation between the convective heating (represented by OLR) and the mean zonal component of the wind at 850 hPa over peninsular India between latitudes 10N and 20N. Found significant and high negative correlation between the five day moving averages of OLR and the zonal wind. OLR is found to lead the zonal wind by about three days.

3 illus, 8 ref

021598   Shyamala B;Iyer B G;Shinde G M;Nair S;Burte M (Regional Meteorological Centre, , Colaba, Mumbai) : Satellite-synoptic-statistical study of very heavy rainfall in Konkan and Gujarat. Proc TROPMET Natl Symp 2001, (NULL), 137-42.

Exceptionally heavy rainfalls were recorded on 13 July 2000 in Konkan, Gujarat and Kutch. These rainfalls were close to record rainfall for their respective nearby IMD stations. Mumbai came to a stand still during 12-13 July with Santacruz recording 31 cm in a 12 hour period 00-12 UTC of 12 July with a maximum intensity of 5 cm per hour during 0830-0930 UTC. COLaba had 22 cm during the same period with a peak intensity of 4 cm per hour during 0030-0130 UTC. Attempts to analyse such extreme monsoon variabilities over Konkan and Gujarat from a statistical-synoptic-satellite perspective and identify the mesoscale-synoptic scale interactions that are necessary and sufficient for such very heavy rain events in Konkan and Gujarat.

4 illus, 7 ref

021597   Shewale M P (Meteorological Department, , Pune-411 005) : Long term fluctuations in seasonal rainfall and drought incidence over arid region of Saurashtra & Kutch. Proc TROPMET Natl Symp 2001, (NULL), 45-9.

Analyses changes in the rainfall pattern during the 100 year period (1901-2000) in monsoon (June-September) in Saurashtra & Kutch. In the first instance time series of rainfall has been analysed to determine presence of trend, if any, and their epochs. Besides simple test like moving averages, various standard test-statistics have been applied. Frequency of receiving certain intervals of seasonal rainfall viz. …40, 41-60, 61-80, 81-100 and <62> 100 cm has been determined and discussed. Dividing the rainfall deficiency into two categories, i.e. 26-50% and <62>50%, instances of moderate and severe drought have been identified and probabilities discussed. The drought and non-drought occurrences have also been subjected to Markov Chain analysis. Association of drought with the occasional warming in the equatorial Pacific Ocean (El Nino episodes) has also been explored. Dependence of Bajra yield on rainfall has also been brought out through correlation analysis and discussed.

1 illus, 1 table, 6 ref

021596   Sharma R V;Prasad T;Kumar S (Regional Meteorological Centre, , Colaba, Mumbai) : Lower and Upper tropospheric winds along west coast of India during south west monsoon. Proc TROPMET Natl Symp 2001, (NULL), 228-32.

Zonal winds during south-west monsoon season for a five year period (1981-1985) over three coastal stations viz Mumbai, Goa and Thiruvananthapuram have been analyzed. The results shows that year-to-year fluctuations of mean zonal wind at any level are minimum over Thiruvananthapuram as compared to those over Goa and Mumbai. No relationship between lower and upper troposphere flow could be inferred. Scatter plots between short duration averages (5 day) of lower and upper winds showed certain alignments of two wind regimes. It is found that correlation coefficients between lower and upper wind regimes are significant and at times, attain values ± 0.7 or ± 0.8. The study indicates that the winds in the lower and upper troposphere during south west monsoon are not independent and unrelated.

3 illus, 1 table, 6 ref

021595   Sengupta S;Chatterjee A (Department of Geology, Presidency College, Kolkata-700 073) : Evidences of faunal activities in the talchir formation, Raniganj Basin, eastern India. Indian J Earth Sci 2000, 27(1-4), 48-50.

Megascopic investigation of the Talchir Formation in parts of Raniganj Basin, eastern India has revealed further evidence of faunal activities in the form of vertical and horizontal burrows, complex trail rocks are indicated in a map and the ichnotaxa are briefly described and illustrated. No fauna body parts or their mould/cast equivalents were encountered in course of the study.

^ssc1 illus, 8 ref

021594   Saxena R M (Meteorology Division, Air Force Administrateive College, , Coimbatore) : Diagnostic study of onset of south west monsoon and its subsequent behaviour during 1993-1997. Proc TROPMET Natl Symp 2001, (NULL), 244-51.

8 illus, 2 tables, 4 ref

021593   Satheesh S K (Centre for Atmospheric and Oceanic Sciences, Indian Institute of Sciences, Bangalore-560 012) : Aerosol radiative forcing over tropical Indian ocean: modulation by sea-surface winds. Curr Sci 2002, 82(3), 310-6.

Atmospheric aerosols have a significant impact on climate because of their important role in modifying the incoming solar and outgoing IR radiation. Recent investigations over the tropical Indian Ocean have shown that the single largest natural contributor of the aerosol visible optical depth are sea-salt aerosols (more than 50% of the natural). Sea-salt aerosol concentration depends on the sea-surface wind speed. The reduction of surface reaching solar flux and increase in the top of the atmosphere (TOA)-reflected solar flux due to the presence of sea-salt aerosols are estimated as a function of wind speed and their role on the radiative forcing and its implication have been examined. It has been shown that in cloudy conditions over the ocean, the effect of sea-salt is to partly offset the positive forcing (heating) by soot aerosol. The surface and TOA forcing by sea-salt aerosols are as high as - 6.1 W m^-2 and - 5.8 W m^-2 respectively (at high wind conditions), which are about 20% and 60%, respectively of the total aerosol forcng (for a mean aerosol optical depth of 0.4) over tropical northern Indian Ocean. Over pristine regions of the Southern Hemisphere where anthropogenic influence is minimal, forcing is mainly determined by the surface wind speed.

9 illus, 2 tables, 3 ref

021592   Sarkar S;Banerjee S;Chakrabarty S (Department of Geological Sciences, Jadavpur University, Calcutta-700 032) : Could Reef growth be the prime reason for the rarity of carbonate hummocky cross-stratifications. Indian J Earth Sci 2000, 27(1-4), 1-10.

Rarity of hummocky cross-stratification (HCS) in carbonate platform sequences is intriguing since the sequences develop almost exclusively in stormprone warm tropical seas. Acritical evaluation of the possible controlling factors, on the basis of avialable data sets, points to the fact that the modes of evolution of carbonate platforms played the key role. Growth of barrier reefs (stromatolite or skeletal) severely restricts formation of HCS in carbonate platforms. Growth of microbial mats and seagrasses as well as sea floor cementation of sediments can cause additional hindrance. Different hydrodynamic behaviour of carbonate clasts, with respect to siliciclastic grains, may have had a direct or indirect control. Bloturbation and diagenesis had certainly modified the geological record of carbonate HCS, but possibly not to the extent of destroying its pre-triassic depositional tenor, Reef growth acted as an anthema to HCS formation, butrelative roles of other possible factors restricting HCS occurrence in carbonate sequences cannot be clearly evaluate in the present level of resolution.

1 illus, 2 tables, 47 ref

021591   Sanjay J;Trivedi D K;Singh S S (NO, Indian Institute of Tropical Meteorology, Pune-411 008) : Real data simulations of tropical systems over Indian region using a high resolution nested mesoscale model. Proc TROPMET Natl Symp 2001, (NULL), 308-14.

Application of a latest version of the Fifth generation Penn State/NCAR Mesoscale Model (MM5) installed in the IITM, Pune computer system is presented. In combination with a multiple nest capability, a four-dimensional data assimilation technique and a variety of physics options, the nonhydrostatic dynamics make the model capable of real data simulations on any scale, limited only by data resolution, quality and computer resources. The capability of MM5 to simulate tropical weather systems ranging from tropical cyclone to localized heavy precipitation events affecting Indian region is demonstrated by selecting a few recent cases.

6 illus, 4 ref

021590   Sanjay J;Mukhopadhyay P;Iyer U;Singh S S (Indian Institute of Tropical Meterology, , Pune-411 008) : An assessment of the JMA analysis of summer monsoon over India during GAME 1998. Proc TROPMET Natl Symp 2001, (NULL), 215-21.

During the GEWEX Asian Monsoon Experiment (GAME) Intensive Observation Period (IOP) enhanced sonde observations were conducted in almost whole Asian monsoon region covering part of India for the period from April to September 1998. Japan Meteorological Agency (JMA) did a reanalysis including the GAME IOP data using their global operational forecast and analysis system at T213/L30 resolution. The data products from four 6-hour analysis cycles are made available to participating Institutes. Compares the large scale circulation and 6-hour forecast mean precipitation from the four cycles with the daily observed station rainfall over India during June to September 1998. Anticipate that this work would be helpful to attain background information on the performance of JMA analysis over Indian region as summer monsoon rainfall is a crucial factor in Asian summer monsoon system. This study attempts to bring out the usefulness of this special data set for NWP research.

6 illus, 3 ref

021589   Samant B;bAJPAI s (Department of Geology, Nagpur University, Law College Campus, Nagpur-400 001) : Fish otoliths from the subsurface cambay shale (lower eocene), Surat lignite field, Gujarat (India)_. Curr Sci 2001, 81(7), 758-9.

^ssc2 illus, 8 ref

021588   Sai Krishnan K C;Madan R;Bhandari S S; Srivastava S N (Indian Meteorological Department, , Lodi Road, New Delhi-110 003) : Thermistor calibration system for Indian radiosonde. Proc TROPMET Natl Symp 2001, (NULL), 377-83.

Sensor accuracy is an important aspect of observation of meteorological parameters usign radiosondes. As the accuracy requirement is made stringent the cost of sensors increases appreciably due to low tolerance requirements. Since radiosondes are one time use device, the cost is to be kept minimum. The temperature-measuring element of the Indian radiosonde (MK-III) is a rod type thermistor, which exhibits a negative temperature coefficient. The resistance of the thermistor varies in the range of 9 K ohms to 1000 K ohms under temperature variation from + 50°C to -90°C. Till now no individual calibration of thermistors was being done in IMD, only sample testing was being done. A set of four constants was being used for implementation in a fourth order polynomial for calculating the temperature. As individual thermistors were not calibrated, the constants were applied to the whole batch of thermistors. The individual variation in the indicated temperature was found to be of the order of 1.0°C. To reduce this a calibration system has been installed in Upper Air Lab of IMD, New Delhi, which provides constants for individual thermistors. The system can calibrate up to 200 thermistors at a time with an accuracy of 0.1° Celsius. The system provides resistance of the sensors at fixed temperature, the data are best fitted with a polynomial and its constants are calculated for later use.

5 illus, 2 tables

021587   Roy Bhowmik S K;Kalsi S R (India Meteorological Department, , New Delhi-110 003) : Analysis of tropical Cyclogenesis over the bay of Bengal. Proc TROPMET Natl Symp 2001, (NULL), 68-73.

An intercomparison of Genesis Parameter (GP) associated with some recent developing and non-developing low pressure systems is made with a view to get an idea of its threshold value for the Bay of Bengal. Model analysis field at the resolution 1° x 1° lat./long. is used for derivation of GP. The study reveals that GP value around 20 x x10-12 sec-2 against T=1.5 has the potential to develop into a severe cyclonic storm. Both for the Orissa super cyclone of October, 1999 and the very severe cyclonic storm with core of hurricane winds of May 1997, GP attained its peak intensity at T=3.5. There was a time lag of about 30 hours between GP max and highest intensity of the system. It appears to provide useful predictive signals for the operational cyclone warning work.

1 illus, 2 tables, 5 ref

021586   Reddy N P C;Rao K M (NO, Regional Centre, National Institute of Oceanography, 176, Lawson's Bay, Visakhapatnam-530 017) : Heavy sediment influx during early holocene: inference from clay mineral studies in a core from the Western Bay of Bengal. Curr Sci 2001, 81(10), 1361-4.

Clay mineral studies were carried out in a 650 cm long sediment core collected at a depth of 2200 m from the north-western Bay of Bengal. Illite is the predominant mineral, followecd by montmorillonite and chlorite. The changes in mineral composition at 380 cm in the core are interpreted to be a transitional period of Pleistocene-Holocene. This is substantiated by the lithological, foraminiferal and geochemical studies of the core. Very high content of illite below 380 cm of the core reflects glacial weathering products of crystalline metamorphic/sedimentary rocks of Himalayas carried by Ganges-Brahmaputra rivers during the late Pleistocene, when the sea level was low. The top 380-cm thick sediment deposition during Holocene is attributed to heavy sediment influx during Mid Termination (MT) (12,500-10,000 years BP), due to increased precipitation and run-off resulting from high intensity monsoonal regime.

3 illus, 1 table, 26 ref

021585   Raval U (NO, National Geophysical Research Institute, P.B. No. 724, Hyderabad-500 007) : Earthquakes over Kutch: a region of `Trident' space-time geodynamics. Curr Sci 2001, 81(7), 809-15.

Kutch peninsula exhibits enigmatically rapid stress accumulation/release like the New Madrid Seismic Zone. Geodynamically, it is a junction of three structural trends and three tectonothermal episodes (69-64 Ma). Combination of mobile belts and plume, evidenced here, favours lithospheric splaying, reactivation, rifting, alkaline complexes: resulting tectonic network may link Kutch with plate boundaries. The 1819 and 2001 events have occurred near the intersection, of such lineaments and accretionary belts, with its margins. Thus, Plate-bopundary forces and loading (uplifts/sediments) appear to superimpose here, over relatively weakened lithosphere; and resulting litho/hydro-spheric instability world contribute to development of the Rann. The crust-mantle interactions are supported by positive gravity anomalies, whose obliguity to kutch rift indicates later reactivation, lower uppermantle velocity near Kutch, and differential uplift/subsidence. Deep geophysical probing is necessary to gain greater understanding of earthquake process.

9 illus, 1 table, 57 ref

021584   Rai Y E A (Regional Meteorological Centre, , 50 College Road, Chennai-600 006) : Application of theory of Chaos in the univariate medium range forecasting of a meteorological parameter. Proc TROPMET Natl Symp 2001, (NULL), 133-6.

2 tables, 5 ref

021583   Raghavan S (NO, , 11/16 Bayline Apts., 15, 2nd Cross St., Radhakrishnan Nagar, Chennai-600041) : Effective utilisation of weather information - especially in severe weather situations. Proc TROPMET Natl Symp 2001, (NULL), 82-7.

3 tables, 4 ref