004250   Kane R P (NO, Instituto Nacional de Pesquisas Espaciais-INPE, C.P. 515, Sao Jose dos Campos-12245-970, SP, Brazil, Email: kane@dge.inpe.br) : QBO and QTO of atmospheric trace elements nitrous oxide and chloroflurocarbons: an update. Mausam 2007, 58(1), 87-100.

An analysis of N₂O (nitrous oxide) and CFC (chlorofluorocarbon) concentrations (monthly values) at various locations during 1978-2001 indicated seasonal variations. When these were minimized by calculating 12-month running means (12m) and 3-year running means (37m) were subtracted from 12m, the residues (12m-37m) showed oscillations with peak spacings in the QBO (quasi-biennial oscillation, 2-3 year) and in the QTO (quasi-triennial oscillation, 3-4 year) regions. The QBO at high northern latitudes roughly resembled the QBO of stratospheric low latitude winds and the QTO at low latitudes resembled the QTO of ENSO (El Nino/Southern oscillation).

6 illus, 47 ref

004249   Hamza V;Babu C A (Atmospheric Sciences Dep, Cochin Univ Science and Technology, Cochin-682 016, Email: hamzavarikoden@yahoo.com) : Boundary layer characteristics associated with sea breeze circulation over Cochin. Mausam 2007, 58(1), 75-86.

Features of sea and land breezes, surface fluxes and drag coefficient over Cochin are studied using more than 300 daily observations of air temperature, wind speed and direction data. The duration and intensity of sea breeze circulation vary with the rain or cloud as it reduces the differential heating Onset of sea breeze is early in summer season for the near equatorial station compared to winter season. Cessation is almost same for all seasons and is around 1900 hours. The sea breeze circulation is almost westerly and land breeze circulation is almost easterly in all the seasons. It is found that in most of the cases, the temperature and wind speed decreases at the time of onset of sea breeze and turning of wind direction with height becomes counter clockwise (backing) during the transition period from land breeze  to sea breeze. In all seasons, the momentum flux is directed downward. High values of momentum flux were found during the presence of sea breeze in pre-monsoon season. Average sensible heat flux is directed upward during the entire period and during nighttime it is almost zero in the winter and monsoon seasons. The intensity of momentum flux decreases during onset and cessation of sea breeze for all the cases. The cold air advection associated with the sea breeze results in the decrease of sensible heat flux at the time of onset of sea breeze. Averaged surface momentum and sensible flux patterns resemble closely to the instantaneous pattern for all the seasons Generally, sea breeze is stronger than land breeze in all the seasons. Accordingly, the drag coefficient power relationship with wind is different for sea breeze and land breeze circulations.

11 illus, 29 ref

004248   Gupta N K;Sharma S;Rizvi S E H (Water management & Research Center, SK Univ Agricultural Sciences & Technology Chatha, Jammu-180 009) : Overland slope calculation - a tool for hydrological analysis and modelling of watersheds. Envir Ecol 2007, 25(2), 288-95.

Paper deals with different methods for overland slope calculation especially in mountainous region along with their feasibility. Four topographic analysis methods were employed to estimate watershed mean slope for three mountainous watersheds having areas ranging from 2.77 to 5,533.5km². Of the four methods employed the mean slope curve method is most accurate but also the most tedious and laborious one. Watershed slopes estimated by the Grid contour method, Mean slope curve method, William and Berndt method and Hortons approach are satisfactory for general purposes and are relativity simple.

5 illus, 5 tables, 5 ref

004247   Gupta H;Shashidhar D;Pereira M;Mandal P; Purnachandra Rao N;Kousalya M;Satyanarayana H V S;Dimri V P (NO, National Geophysical Research Institute, Uppal Road, Hyderabad-500 007, Email: harshgupta@nic.in) : Earthquake forecast appears feasible at Koyna, India. Curr Sci 2007, 93(6), 843-8.

At the Koyha reservoir in western India, it is observed that earthquakes of magnitude (M) 4-5 are often preceded by well-defined clusters of foreshocks of M ≤ 3, referred to as nucleation that is found to last typically for 100-400 h. Based on continuous monitoring of seismic activity, a nucleation pattern was identified and an earthquake of M 4+ was forecasted on 16 May 2006. An earthquake of M 4.2 did occur on 21 May 2006 within the forecasted parameters. The continued seismic activity in such an isolated and well-monitored site probably makes Koyna a suitable locale to pursue meaningful study of earthquake precursors.

4 illus, 2 tables, ref

004246   Gupta A;Kale V S;Owen L A;Singhvi A K (School of Geography, Leeds Univ, Leeds, LS2 9JT, UK, Email: vskale@unipune.ernet.in) : Late quaternary bedrock incision in the Narmada river at Dardi falls. Curr Sci 2007, 93(4), 564-74.

Fluvial incision in bedrock is common in many rivers of the Indian Peninsula. Author investigated a site in the gorge of the Narmada river at Dardi Falls that displays geomorphic evidence of intense bedrock erosion. Also report here a terrestrial cosmogenic radionuclide date from an eroded rock surface in Peninsular India. Terrestrial cosmogenic radionuclide dating of the rock surface adjacent to the inner gorge indicated that the minimum age of the gorge is 40 ka. Authors suggest that the present gorge has developed in two phases, separated by a period of large-scale aggradation that filled the gorge with alluvium. Gorge formation is most likely associated with tectonic activity in the Son-Narmada-Tapi lineament zone. Erosion at this scale also requires large palaeodischarges with high unit stream power. This study illustrates the powers of combining newly developing geomorphic, DEM and geochronological methods to elucidate the dynamics and nature of landscape evolution.

3 illus, 1 table, 2 ref

004245   Giri R K;Meena L R;Bhandari S S;Bhatia R C (India Meteorological Dep, , Lodi Road, New Delhi-110 003, Email: rkgiri_ccs@rediffmail.com) : Integrated water vapour from GPS. Mausam 2007, 58(1), 101-6.

Water vapour is highly variable in space and time, and plays a large role in atmospheric processes that act over a wide range of temporal and spatial scales on global climate to micrometeorology. This paper deals with a new approach to remotely sense the water vapour based on the Global Position System (GPS). The signal propagating from GPS satellites to ground based receivers is delayed by atmospheric water vapour. The delay is parameterized in terms of time varying Zenith-Wet Delay (ZWD), which is retrieved by stochastic filtering of GPS data. With the help of surface pressure and temperature readings at the GPS receiver, the retrieved ZWD can be transformed into Integrated Water Vapour (IWV) overlying at the receiver with little additional uncertainties. In this study the Zenith Total time Delay (ZTD) data without met package is retrieved using the GAM IT (King and Bock, 1997) GPS data processing software developed by Massachusetts Institute of Technology (MIT) for the period of January 2003 to February 2003 for two stations New Delhi and Bangalore. The IWV retrieved from GPS and its comparison with Limited Area Model (LAM) retrieved IWV shows fairly good agreement.

2 illus, 14 ref

004244   Garg D;Singh R V (Chemistry Dep, Rajasthan Univ, Jaipur-302 004, Email: singh-rv@uniraj.ernet.in) : Look into the physico-chemical characteristics of the ground water of Bharatpur in Rajasthan during the pre-monsoon season, 2006. Int J chem Sci 2006, 4(4), 775-82.

Describes the important results of the physico-chemical analysis of the ground water samples of the open wells, bore wells and hand pumps of the Bharatpur district during the Pre-monsoon season, 2006. Bharatpur is well known place because of "Keoladeo Ghana National Park". Some important physico-chemical parameters like pH, temperature, total alkalinity, total hardness, chloride, sulphate, nitrate, fluoride, calcium hardness, magnesium hardness, carbonate hardness, non-carbonate hardness and total dissolved solid, were analysed for water. The analytical results reveal that the water of most of all the places is hard, hence unsuitable for drinking purpose. Water of most of the places is highly contaminated with total dissolved solids which causes gastrointestinal irritation. Overall, the quality of water is unsatisfactory for drinking purposes.

2 tables, 8 ref

004243   Deshpande S M (Geology Dep, Institute of Science, Aurangabad) : Groundwater quality of Satara and Itkheda area for irrigation purpose. Bioinfolet 2007, 4(2), 171.

1 table, 4 ref

004242   Dash S K;Hunt J C R (Centre for Atmospheric Sciences, Indian Institute of Technology Delhi, Hauz Khas, New Delhi-110 016, Email: skdash@cas.iitd.ernet.in) : Variability of climate change in India. Curr Sci 2007, 93(6), 782-8.

Meteorological measurements in India are analysed showing marked trends of increasing temperature over the past quarter century, but significant variations in these trends during different seasons and over different regions of India. Marked differences between the variations in minimum temperatures in North and South India have been brought out. Tentative explanations are proposed in terms of the effects of variations in cloudiness. The effects of airborne dust on clouds and on precipitation, as well as the interactions between air flow over the mountains and the monsoon may also have a significant effect on climatic variations. The practical implications of these changes in climate for agriculture and the effects on human health through increasing temperature are likely to be serious, and vary significantly across the regions of India. For India, the importance of dealing with climate change as an integral part of its economic and social development is strongly emphasized.

10 illus, 18 ref

004241   Charan Singh;Loe B R (India Meteorological Dep, , New Delhi-110 003, Email: csingh1964@yahoo.co.in) : Trend of shift in the area of cyclo-genesis over north Indian ocean. Mausam 2007, 58(1), 49-58.

Cyclo-genesis over north Indian Ocean (Bay of Bengal and the Arabian Sea) has been studied with reference to the formation and shift of cyclo-genesis area. The frequency of formation of cyclones during a particular month and year for the period of study has been presented. The study has shown that the maximum number of cyclo-genesis occurred during the month of July followed by August and September. Cyclo-genesis was about three limes more in the Bay of Bengal as compared to that in the Arabian Sea. Areas favourable for cyclo-genesis were found between Lat. 15.0° N to 22.5° N and Long. 86.0°E to 92.0° E over the Bay of Bengal and Lat. 7.0° N to 12.5° N and 60.0° E to 74.0°E over the Arabian sea while meander over north Indian ocean, some times its shift significantly. Standard deviation of number of cyclones has been computed for the decades from 1891-2000. It was found that it was maximum (1.96) during 1941-1950 followed by 1981-1990(1.92).

13 illus, 1 table, 13 ref

004240   Chadwick B;Vasudev V N;Hegde G V;Nutman A P (NO, , 17 St Mary's Park, Ottery St Mary EX11 1JA, UK) : Structure and shrimp U/Pb zircon ages of granites adjacent to the Chitradurga schist belt: implications for neoarchaean convergence in the Dharwar craton, southern India. J Geol Soc India 2007, 69(1), 5-24.

Shapes of the granites and their emplacement in relation to the structure of the Ranibennur and Chitradurga schist belts in the west of the craton are modelled as a mid-crustal part of a craton-wide imbricate fold-thrust belt. The relationships show that whereas some Neoarchaean granites in the craton were emplaced prior to, or during, SW-vergent thrust thickening, most granites and related plutonic suites in the foreland and accretionary complex were emplaced later as multipulse injections in steep NW-SE sheets or wedges during orogen-parallel, sinistral and dextral shear. Steep high-strain zones in the foreland and accretionary complex are interpreted as listric structures that root into an attachment at a depth of ca. 18-20 km in accord with the depth of the boundary between upper and lower crust placed at ca. 23 km from seismic reflection data published in 1979 and in more recent studies. The new structural observations and zircon dating, combined with published isotopic age data, show that the inner margin of the foreland in the west of the craton and the outer margin of the accretionary complex in the east are linked in a diffuse, steeply dipping, orogen-parallel boundary zone at least 200 km wide.

13 illus, 83 ref

004239   Bhalla R S (NO, Foundation for Ecological Research, Advocacy and Learning, No. 27, 2nd Cross, Appavou Nagar, Vazhakulam, Puducherry-605 012, Email: bhalla@feralindia.org ) : Do bio-shields affect tsunami inundation?. Curr Sci 2007, 93(6), 831-3.

Conversion of coastal sand dunes to plantations has intensified dramatically after the tsunami of December 2004, driven largely by the belief that bio-shields mitigated tsunami inundation. This assumption was tested using field-based mapping and remote sensing. A regression between the Normalized Difference Vegetation Index and inundation distance was non-significant, questioning the premise for large-scale bio-shield plantations, mostly Casuarina equisetifolia, an exotic timber with unquantified ecological impacts. These plantations may obliterate the natural sand dune ecosystems along the Coromandel coast, which are an important natural defence and provide a range of ecological goods and services.

2 illus, 26 ref

004238   Abdul Azeez K K;Harinarayana T (NO, National Geophysical Research Institute, Uppal Road, Hyderabad-500 007, Email: azeez@ngri.res.in) : Magnetotelluric evidence of potential geothermal resource in Puga, Ladakh, NW Himalaya. Curr Sci 2007, 93(3), 323-9.

Puga area in eastern Ladakh, Jammu and Kashmir, is known to be the most promising geothermal field in India, as pointed out by geo-scientific studies in the area. However, lack of deep subsurface information put constraints to the geothermal resource evaluation in Puga. The recent magnetotelluric study in Puga revealed anomalous conductive (<126>5 Ohm.m) structure at a depth of 2 km in the area of geothermal manifestation. Analysis of temperature logs indicated a high temperature (<126>260°C) associated with the anomalous conductive structure and signifies potential geothermal resource in the area. Author discuss the results in the context of geothermal resource utilization for power generation in the area.

4 illus, 32 ref

003637   Vikas C;Kushwaha R K;Pandit M K (Central Ground Water Board, KR, , Kedaram Complex, Kesavadasapuram, Trivandrum-4, Email: mpandit_jpl@sancharnet.in) : Hydrochemical status of groundwater in district Ajmer (NW India) with reference to fluoride distribution. J Geol Soc India 2009, 73(6), 773-84.

High fluoride in groundwater has been reported from many parts of India. However a systematic study is required to understand the behaviour of fluoride in natural water in terms of local hydrogeological setting. climatic conditions and agricultural practices. Present study is an attempt to assess hydrogeochemistry of groundwater in Ajmer district in Rajasthan to understand the fluoride abundance in groundwater and to deduce the chemical parameters responsible for the dissolution activity of fluoride. Ajmer district falls in the semi-arid tract of central Rajasthan and is geologically occupied by Precambrian rocks (granites, pegmatites, gneisses, schists etc) where groundwater occurs under unconfined condition. A total of 153 well-water samples, representing an area of 8481 km² (further subdivided into eight blocks), were collected and chemically analyzed. The results of chemical analyses (pre-monsoon 2004) show fluoride abundance in the range of 0.12 to 16.9 mg/I with 66% of the samples in excess of permissible limit of 1.5 mg/1. Presence of fluoride bearing minerals in the host rock, the chemical properties like decomposition, dissociation and dissolution and their interaction with water is considered to be the main cause for fluoride in groundwater. Chemical weathering under arid to semi-arid conditions with relatively high alkalinity favours high concentration of fluoride in groundwater. Dental and skeletal fluorosis are prevalent in the study area which can be related to the usage of high fluoride groundwater for drinking. The suggested remedial measures to reduce fluoride pollution in groundwater include dilution by blending, artificial recharge, efficient irrigation practices and well construction.

5 illus, 1 table, 34 ref

003636   Vidyashankar H V;Govindaiah S (Studies in Geology Dep, University of Mysore, Manasagangothri, Mysore-570 006) : Ore petrology of the V-Ti magnetite (Lodestone) layers of the Kurihundi area of Sargur schist belt, Dharwar craton. J Geol Soc India 2009, 74(1), 58-68.

V-Ti magnetite layers (lodestone) occur within the layered gabbro-anorthosites-ultramafic rocks emplaced into the migmatitic gneisses close to the high grade Archeaen Sargur supracrustal rocks in the Kurihundi area. The ore petrographic studies of the lodestone reveal the presence of primary Ti-magnetite, ilmenite, ulvospinel, pleonaste, hematite and pyrite, chalcopyrite, pyrrhotite and secondary Ti-maghemite, martite and goethite as well as secondary covellite. These layers contain Ti-magnetite (60%) and ilmenite (30%) with silicates (<60>5%) exhibiting granular mosaic texture with well-defined triple junctions and are classified as adcumulus rocks. The grain-boundary relationships in the ores indicate considerable postcumulus growth and readjustment due to combined effects of sintering and adcumulus growth. Intergrowth textures (ulvospinel, ilmenite and pleonaste in Ti-magnetite and hematite in ilmenite) reflects exsolution features crystallized from solid-solutions compositions under different conditions of oxygen fugacities. Larger bodies of pleonaste and ilmenite in Ti-magnetite become lensoid or rounded in outline and these morphological modifications took place during the regional upper amphibolite to lower granulite facies metamorphism at 2.6 Ga ago. The lodestone contains high TiO₂ (20 to 22.59 wt%), with V₂O₅ (0.85 to 1.15%) and Fe₂O₃^t (72.03 to 74.25%). Ti-magnetite shows alteration to Ti-maghemite, martite and goethite due to low temperature oxidation and hydration during weathering.

18 illus, 1 table, 27 ref

003635   Veeraiah B;Ramadass G;Himabindu D (NO, National Geophysical Research Institute (CSIR), Uppal Road, Hyderabad-500 007, Email: veerngri@yahoo.com) : Subsurface criterion for predictive exploration of kimberlites from Bouguer gravity in the eastern Dharwar craton, India. J Geol Soc India 2009, 74(1), 69-77.

Archaean-Proterozoic Dharwar craton has many recorded occurrences of diamondiferous kimberlites. Reports of kimberlite emplacement in parts of the tectonically complex eastern Dharwar craton and a significant density contrast between kimberlites and the host peninsular gneisses motivated us to conduct gravity studies in the Narayanpet-Irladinne area of the eastern Dharwar craton. This region is contiguous with the Maddur-Narayanpet kimberlite that lies to its north, while the river Krishna lies to its south. From observed association of reported kimberlites in the Maddur-Narayanpet field with subsurface topography of the assumed three-layer earth section obtained by Bouguer gravity modelling, we developed a subsurface criterion for occurrence of kimberlites in the study area. Using this criterion, five potential zones for kimberlite localization were identified in the Narayanpet-Irladinne region, eastern Dharwar craton.

6 illus, 35 ref

003634   Tewari R C;Singh D P;Khan Z A (Geology Dep, Sri J.N.P.G. College, Lucknow-226 001, Email: ram_tewari@yahoo.com) : Application of Markov chain and entropy analysis to lithologic succession - an example from the early Permian Barakar Formation, Bellampalli coal field, Andhra Pradesh,India. J Earth Syst Sci 2009, 118(5), 583-96.

Statistical approach by a modified Markov process model and entropy function is used to prove that the early Permian Barakar Formation of the Bellampalli coal field developed distinct cyclicities during deposition. From results, the transition path of lithological states typical for the Bellampalli basin is as: coarse to medium-grained sandstone ÷ interbedded fine-grained sandstone/shale ÷shale ÷ coal and again shale. The majority of cycles are symmetrical but asymmetrical cycles are present as well. The chi-square stationarity test implies that these cycles are stationary in space and time. The cycles are interpreted in terms of in-channel, point bar and overbank facies association in a fluvial system. The randomness in the occurrence of facies within a cycle is evaluated in terms of entropy, which can be calculated from the Markov matrices. Two types of entropies are calculated for every facies state; entropy after deposition E (post) and entropy before deposition E (pre), which together form entropy set; the entropy for the whole system is also calculated. These values are plotted and compared with Hattori's idealized plots, which indicate that the sequence is essentially a symmetrical cycle (type-B of Hattroi). The symmetrical cyclical deposition of early Permian Barakar Formation is explained by the lateral migration of stream channels in response to varying discharge and rate of deposition across the alluvial plain. In addition, the fining upward cycles in the upper part enclosing thick beds of fine clastics, as well as coal may represent differential subsidence of depositional basin.

12 illus, 6 tables, 34 ref

003633   Sreekumar S (Geology and Environmental Sciences Dep, Christ College, Irinjalakuda-680 125, Email: sreeavani@rediffmail.com) : Techniques for slope stability analysis: site specific studies from Idukki district, Kerala. J Geol Soc India 2009, 73(6), 812-20.

The occurrences of slope failures are frequent in Idukki district of Kerala state particularly along the road cuttings and hill slopes causing disruption in traffic, loss of lives and property. This demands a critical evaluation of stability of slopes along the hill roads. This paper deals with stability analysis of a typical hard rock profile at Chuzhappu and a lateritic profile at Kumili along the road connecting Kottayam and Kumili. A large number of factors have been examined and studied; the orientation of discontinuities has been identified as one of the major inherent factors influencing slope instability along Chuzhappu hard rock profile. These have been analysed carefully using stereographic/equal area projection technique in order to determine the vulnerability to slope failure and to understand the type of rock slide that can .occur in this profile. The buoyant force of water acting along the discontinuities after heavy rain storm further aids the down slope movement. As the laterite slope is mostly homogeneous, Bishops method and Swedish method were adopted for stability analysis of laterite slope at Kumili. The study also examines the efficacy and applicability of the different methods employed in soil mechanics to assess the stability of laterite slope .The results obtained by this method are compared by actual field conditions. The stability assessment indicates that two sectors at Chuzhappu and one sector at Kumili profile are at the geo-technical threshold of failure, when piezometric head rises during rainstorm. The study-indicates-that these methods are highly useful in determining the Factor of Safety in profiles with similar geological setting.

6 illus, 4 tables, 18 ref

003632   Son Y B;Gardner W D;Mishonov A V;Richardson M J (Fisheries Dep, Nagasaki University, 1-14 Bunkyo, Nagasaki, Nagasaki 852-8521, Email: sonyb@nagasaki-u.ac.jp) : Model-based remote sensing algorithms for particulate organic crbon (POC) in the northeastern Gulf of Mexico. J Earth Syst Sci 2009, 118(1), 1-10.

Hydrographic data, including particulate organic carbon (POC) from the Northeastern Gulf of Mexico (NEGOM) study, were combined with remotely-sensed SeaWiFS data to estimate POC concentration using principal component analysis (PCA). The spectral radiance was extracted at each NEGOM station, digitized, and averaged. The mean value and spurious trends were removed from each spectrum. De-trended data included six wavelengths at 58 stations. The correlation between the weighting factors of the first six eigenvectors and POC concentration were applied using multiple linear regression. PCA algorithms based on the first three, four, and five modes accounted for 90, 95, and 98% of total variance and yielded significant correlations with POC with R2 = 0.89, 0.92, and 0.93. These full waveband approaches provided robust estimates of POC in various water types. Three different analyses (root mean square error, mean ratio and standard deviation) showed similar error estimates, and suggest that spectral variations in the modes defined by just the first four characteristic vectors are closely correlated with POC concentration, resulting in only negligible loss of spectral information from additional modes. The use of POC algorithms greatly increases the spatial and temporal resolution for interpreting POC cycling and can be extrapolated throughout and perhaps beyond the area of shipboard sampling.

4 illus, 1 table, 32 ref

003631   Singh R K;Sengupta B;Bali R;Shukla B P; Gurnadharao V V S;Srivastava R (NO, Central Pollution Control Board, Ministry of Environment and Forests,, New Delhi, Email: rsingh1962@rediffmail.com) : Identification and mapping of chromium (VI) plume in groundwater for remediation: a case study at Kanpur, Uttar Pradesh. J Geol Soc India 2009, 74(1), 49-57.

With only twenty five percent population living in urban areas, India has cities amongst the biggest in the world. Urban growth in most of Indian cities is concomitant with rise in water demand for community, as well as, for industrial purposes. The complex situation resulting from indiscriminate disposal of waste and its severe impact on groundwater quality is set for continuous worsening mainly for want of sustained effort aimed at site-specific remediation. The study, a prerequisite for actual remediation in an industrial city of Kanpur, India, envisages detailed investigation about pollutant transport, evaluation of concept of Bio-remediation and a range of other options and finally full scale implementation of the best suited. Drilling of piezometers and resistivity survey indicates that the area is constituted of alluvial sands, gravels and their various admixtures. Chemical analysis of water samples collected from piezometers and hand pumps shows the presence of hexavalent chromium rich horizons at various depths. The alarming concentration of this carcinogenic heavy metal of the order of 16.3 mg/l against the permissible concentration (of 0.05 mg/l) for drinking water and high concentration within sediments of the area poses a major threat to the entire ecosystem. The projection of migration contaminant plume of hexavalent chromium as depicted is indicative of a concentrated extent of core zone existing in shallow alluvial aquifer, which may be targeted for interception by remedial measures. Elaborates the source, potential and monitoring the migration of the pollutant plume is the first field scale study of its kind in the country. The findings of these studies are of strong relevance in addressing the ground water pollution due to indiscriminate disposal practices of hazardous waste in areas located within the alluvial zones.

5 illus, 3 tables, 15 ref

003630   Shenoi S S C;Nasnodkar N;Rajesh G;Jossia Joseph K;Suresh I;Almeida A M (NO, National Institute of Oceanography (Council of Scientific and Industri, Dona Paula, Goa-403 004, Email: shenoi@incois.gov.in) : Diurnal ranges of Sea Surface Temperature (SST) in the north Indian Ocean. J Earth Syst Sci 2009, 118(5), 483-96.

Describes the variability in the diurnal range of SST in the north Indian Ocean using in situ measurements and tests the suitability of simple regression models in estimating the diurnal range. SST measurements obtained from 1556 drifting and 25 moored buoys were used to determine the diurnal range of SSTs. The magnitude of diurnal range of SST was highest in spring and lowest in summer monsoon. Except in spring, nearly 75 -80%of the observations reported diurnal range below 0.5°C. The distributions of the magnitudes of diurnal warming across the three basins of north Indian Ocean (Arabian Sea, Bay of Bengal and Equatorial Indian Ocean) were similar except for the differences between the Arabian Sea and the other two basins during November-February (winter monsoon) and May. The magnitude of diurnal warming that depended on the location of temperature sensor below the water level varied with seasons. In spring, the magnitude of diurnal warming diminished drastically with the increase in the depth of temperature sensor. The diurnal range estimated using the drifting buoy data was higher than the diurnal range estimated using moored buoys fitted with temperature sensors at greater depths. A simple regression model based on the peak solar radiation and average wind speed was good enough to estimate the diurnal range of SST at <126>1.0 m in the north Indian Ocean during most of the seasons except under low wind-high solar radiation conditions that occur mostly during spring. The additional information on the rate of precipitation is found to be redundant for the estimation of the magnitude of diurnal warming at those depths.

9 illus, 5 tables, 30 ref

003629   Shekhawat M S;Sharma V (Geology Dep, M.L. Sukhadia University, Udaipur-313 001, Email: shekhawatgeol@yahoo.com) : Mineralogical characteristics and mineral economics of Kaolinite deposit of Sawa area, Chittaurgarh, Rajasthan. J Geol Soc India 2009, 74(1), 27-34.

Large deposit of low-grade kaolinite is occurring within the rocks of Lower Vindhyan Supergroup southwest of Chittaurgarh, Rajasthan. The deposit is being utilised by open-cast, manual to semi-mechanised methods of mining. Kaolinite produced is being marketed without processing. Earlier, nearly 60% of the kaolinite produced from the area was consumed by cement industries, but in recent past, utilisation of low-grade kaolinite has been minimised by cement industries in production of ordinary cement and hence its production has significantly declined. Mineralogical studies reveal that kaolinite is the main clay-mineral and quartz, calcite, iron-oxides and biotite are present as non-clay minerals in clay deposit of the area. Chemical analysis of the kaolinite show that alumina ranges from 15 to 35% while, silica and iron varies from 51 to 78% and 0.25 to 2.50% respectively.

4 illus, 3 tables, 22 ref

003628   Sharma A;Dutta S (Environmental Studies Dep, M.D.S. University, Ajmer-305 009) : Water quality surveillance of Panchana Dam irrigation project, Karauli, Rajasthan. Nat Envir Pollut Technol 2009, 8(1), 147-50.

Water chemistry provides precious parameters to evaluate the environmental impact assessment of irrigation projects. The Panchana Dam is situated 12 km north to Karauli in the eastern part of Rajasthan. Panchana Dam site falls under the eastern gravelly/rocky plateau with outliers of Aravallis, and the total catchment area is about 621.60 sq. km and the command area is about 10606 ha. The climate of Panchana Dam area is almost semi-arid and comparatively milder with distinct winter, summer and rainy seasons. The summer season is from the middle of March to June, being extreme in the month of June. The study revealed that the water has pH (7.6-8.3), electrical conductivity (260-300 æmhos), total dissolve solids (169-195 mg/L), phosphate (0.121-1.939 mg/L), total alkalinity (410-650 mg/L), carbonate alkalinity (20-100 mg/L), bicarbonate alkalinity (390-610 mg/L), total hardness (92-128 mg/L), calcium hardness (22.44-33.67 mg/L), magnesium hardness (69.56-90.33 mg/L), chloride (24.14 -28.4 mg/L), and acidity (2.0-4.0 mg/L). Water in Panchana Dam irrigation project (PIP) is influenced by hydrology and related factors, which cause variations in nutrients present in a particular time. PIP as wetland plays an important role to develop the favourable microclimatic conditions for biodiversity as a whole. The physico-chemical analysis of water samples from this area showed that the water is within the safe limits of drinking water quality. Seasonal variations in water quality are due to intrinsic and extrinsic factors of the aquatic system.

1 illus, 2 tables, 10 ref

003627   Salaskr P B;Yeragi S G (NO, , Naushad Ali Sarovar, Samvardhins, Powai, Mumbai-400 072) : Rothfer diversity in Powai lake, Mumbai, Maharashtra. J Aquatic Biol 2009, 24(2), 21-5.

Rotifera were the highest in density in Zooplankton assemblage of the lake Powai and estimated to be 50.96% of the total zooplankton population. In fresh water biology, the importance of rotifers is beyond question for they inhabit practically any body of water from a trickle on the rocks to large rivers, from bog holes to salt lakes from ephemeral pools and to the pelagial of great lakes. In tropical countries, the limnoplankton always comprises rotifers in which Brachionus is a prominent species.

1 table, 26 ref

003626   Roy S;Venkatesh A S (MNP Div, National Metallurgical Lab, Jamshedpur, Email: roy.subrata11@yahoo.com) : Mineralogy and geochemistry of banded iron formation and iron ores from eastern India with implications on their genesis. J Earth Syst Sci 2009, 118(6), 619-41.

Geological complexities of banded iron formation (BIF) and associated iron ores of Jilling-Langalata iron ore deposits, Singhbhum-North Orissa Craton, belonging to Iron Ore Group (IOG) eastern India have been studied in detail along with the geochemical evaluation of different iron ores. The geochemical and mineralogical characterization suggests that the massive, hard laminated, soft laminated ore and blue dust had a genetic lineage from BIFs aided with certain input from hydrothermal activity. The PAAS normalized REE pattern of Jilling BIF striking positive Eu anomaly, resembling those of modern hydrothermal solutions from mid-oceanic ridge (MOR). Major part of the iron could have been added to the bottom sea water by hydrothermal solutions derived from hydrothermally active anoxic marine environments. The ubiquitous presence of intercalated tuffaceous shales indicates the volcanic signature in BIF. Mineralogical studies reveal that magnetite was the principal iron oxide mineral, whose depositional history is preserved in BHJ, where it remains in the form of martite and the platy hematite is mainly the product of martite. The different types of iron ores are intricately related with the BHJ. Removal of silica from BIF and successive precipitation of iron by hydrothermal fluids of possible meteoric origin resulted in the formation of martite-goethite ore. The hard laminated ore has been formed in the second phase of supergene processes, where the deep burial upgrades the hydrous iron oxides to hematite. The massive ore is syngenetic in origin with BHJ. Soft laminated ores and biscuity ores were formed where further precipitation of iron was partial or absent.

16 illus, 6 tables, 76 ref

003625   Ray D;Mevel C;Banerjee R (NO, National Centre for Antarctic and Ocean Research, Goa-403 804, Email: dwijesh@rediffmail.com) : Hydrothermal alteration studies of gabbros from Northern Central Indian Ridge and their geodynamic implications. J Earth Syst Sci 2009, 118(6), 659-76.

Mylonitic gabbro and altered gabbro were recovered from off-axis high and corner high locations at ridge-transform intersection, adjacent to Vityaz transform fault of the slow spreading (32-35mm/yr, full spreading) Northern Central Indian Ridge. Both the varieties show signatures of extensive alteration caused due to interaction with sea water. Mylonitic gabbro represents high temperature metamorphism (<126>700-800°C) and comprised of hornblende mineral which exhibits well defined foliation/gneissic appearance along with dynamically recrystallised plagioclase grains frequently intercalated with magnetite-ilmenite. Altered gabbro from corner high generally includes low temperature greenschist grade (<126>300°C) mineralogical assemblages: chlorite, albite, quartz and locally magnesio hornblende. Crystal plastic deformation resulted in mylonite formation and often porphyroclasts of plagioclase and clinopyroxene grains, while altered gabbro locally exhibits cataclastic texture. Presence of Vityaz transform fault and adjacent megamullion at the weakly magmatic ridge-transform intersection and off-axis high locations prompted the present scenario very much conducive for hydrothermal circulation and further facilitate the exhumation of present suite of gabbro.

11 illus, 7 tables, 45 ref

003624   Rathod S D;Patil N N (Zoology Dep, B.N. Bandodkar College of Science, Jnanadweepa, Chendani, Thane-400 601, Email: sudesh_rathod@yahoo.co.in) : Assessment of some hydrological parameters of Ulhas river estuary, in the vicinity of Thane city Maharashtra State. J Aquatic Biol 2009, 24(2), 103-8.

Study of coastal water quality plays important role in evaluating and determining the pollution status and health of the water. Ulhas river estuary is one of the important water bodies in Thane district. Entire stretch of estuary was arbitrarily divided into three zones. Physical and chemical variables of water were monitored month-wise in the year 2004-2005. In the present study the entire stretch of estuary showed high values of BOD, PO4-P, NO₃-N, Suspended solids and hypoxia suggesting deterioration of the estuary.

7 illus, 2 tables, 15 ref

003623   Raju Kumar;Shrivastava J P (Geology Dep, University of Delhi, Delhi-110 007) : Geochemistry of basic dykes from Betul-Jabalpur area in the Deccan volcanic province. J Geol Soc India 2009, 74(1), 95-107.

Dykes exposed in the Betul-Jabalpur area, lie parallel to E-W trending Narmada-Son and Tapti lineaments in the Deccan volcanic province. These dykes show a variety of textural features and contain plagioclase (33-45%), clinopyroxene, olivine, magnetite and glass. These dykes are mainly basalt and basaltic andesite. Betul-Jabalpur and Tapti dykes show increase in sub-alkalis (K₂O+Na₂O) with the rise in SiO₂ values. Their data plots confine to the sub-alkalic array suggesting fractional crystallization as the dominant process. The high field strength elements in these dykes also show close correlation with the dykes south of the Tapti valley. Low concentration of Rb, Ba and V in Betul-Jabalpur dykes indicate that they are less contaminated than the other dykes of Deccan volcanic province. The large-scale chemical similarity in the major and trace elemental composition of the Betul-Jabalpur and south of Tapti valley dykes suggests their origin from a common magma type, possibly derived from the fractionation of isolated high gravity mafic-ultramafic igneous bodies positioned 6-8 km below the surface, trending parallel to the Narmada-Tapti rift zone.

10 illus, 3 tables, 39 ref

003622   Rajendran C P;John B;Sreekumari K;Rajendran K (Centre for Earth Sciences, Indian Institute of Science, Bangalore-560 012) : Reassessing the earthquake hazard in Kerala based on the historical and current seismicity. J Geol Soc India 2009, 73(6), 785-802.

Given the lack of proper constraints in understanding earthquake mechanisms in the cratonic interiors and the general absence of good quality database, here reassess the seismic hazard in the province of Kerala, a part of the 'stable continental interior', based on an improveh-historical and instrumental database. The temporal pattern of the current seismicity suggests that <62>60% of the microtremors in Kerala occurs with a time lag after the peak rainfall, indicating that hydroseismicity may be a plausible model to explain the low-level seismicity in this region. Further, an increment in overall seismicity rate in the region in the recent years is explained as due to increased anthropogenic activities, which includes changes in hydrological pathways as a consequence of rapid landscape changes. Our analyses of the historical database eliminate a few events that are ascribed to this region; this exercise has also led to identification of a few events, not previously noted. The improved historical database essentially suggests that the central midland region is more prone to seismic activity compared to other parts of Kerala. This region appears to have generated larger number of significant earthquakes; the most prominent being the multiple events (doublets) of 1856 and 1953, whose magnitudes are comparable to that of the 2000/2001 (central Kerala) events. Occurrences of these historical events and the recent earthquakes, and the local geology indicative of pervasive faulting as shown by widely distributed pseudotachylite veins suggest that the NNW -SSE trending faults in central midland Kerala may host discrete potentially active sources that may be capable of generating light to moderate size earthquakes. The frequency of earthquakes in central Kerala evident from the historical database requires that the seismic codes stipulated for this region are made mandatory.

7 illus, 2 tables, 51 ref

003621   Radhakrishna Murthy I V;Bangaru Babu S (Geophysics Dep, Andhra University, Visakhapatnam-530 003, Email: ivr_murthy@yahoo.com) : Magnetic anomalies across Bastar craton and Pranhita-Godavari basin in south of central India. J Earth Syst Sci 2009, 118(1), 81-7.

Aeromagnetic anomalies over Bastar craton and Pranhita -Godavari (P -G) basin in the south of central India could be attributed to NW -SE striking maficc intrusives in both the areas at variable depths. Such intrusions can be explained considering the collision of the Bastar and Dharwar cratons by the end of the Archaean and the development of tensile regimes that followed in the Paleoproterozoic,facilitating intrusions of mafic dykes into the continental crust. The P -G basin area, being a zone of crustal weakness along the contact of the Bastar and Dharwar cratons, also experienced extensional tectonics. The inferred remanent magnetization of these dykes dips upwards and it is such that the dykes are oriented towards the east of the magnetic north at the time of their formation compared to their present NW -SE strike. Assuming that there was no imprint of magnetization of a later date, it is concluded that the Indian plate was located in the southern hemisphere,either independently or as part of a supercontinent, for some span of time during Paleoproterozoic and was involved in complex path of movement and rotation subsequently. Presents a case study of the utility of aeromagnetic anomalies in qualitatively deducing the palaeopositions of the landmasses from the interpreted remanent magnetism of buried intrusive bodies.

4 illus, 1 table, 10 ref

003620   Purushothaman D;Mohakul J P;Saha A; Vidyadharan K T;Rajendran N (Geological Survey of India, , Opn K & G, K.SA. Layout, Bangalore-560 078, Email: mohajay@yahoo.com) : Soil and stream sediment based geochemical mapping: a case study in Goa. J Geol Soc India 2009, 73(6), 744-6.

Geochemical mapping has been carried out in Goa using soil/laterite and stream sediment as media. The geochemical maps for U, Th, Nb and Ta show a conspicuous pattern in the NW part of Goa. The anomaly axis shows a NE-SW trend which is across the formational trend. The nickel and copper distribution around Usgaon area, east of Ponda, have indicated anomalous signature in the northern continuation of the Usgaon ultramafic complex.

1 illus, 6 ref

003619   Puranik D M;Karekar R N (Atmospheric and Space Sciences Dep, University of Pune, Pune-411 007, Email: dileepmp@unipune.ernet.in) : Western disturbances seen with AMSU-B and infrared sensors. J Earth Syst Sci 2009, 118(1), 27-39.

Western disturbances (WD) of winter and pre-monsoon seasons are the important sources of rainfall in the Indo-Gangetic plains. WDs are troughs or circulations in the westerly winds modified by the Himalayas. Operationally, WDs are monitored using infrared (IR) and water vapour (WV) images. Advanced Microwave Sounding Unit-B (AMSU-B), flying onboard the NOAA satellites, also allows WDs to be monitored in five microwave frequencies. Two are in water vapour window (89, 150 GHz) and three are absorption channels (centred at 183.31 GHz). Unlike the top of cloud view in IR or WV, AMSU-B radiances show the effect of moisture and hydrometeors in different layers. Two cases of WD (17 April 2001 and 18-19 February 2003) are discussed using the microwave data from AMSU-B and the IR and WV data from Meteosat-5. The aim here is to demonstrate the skill of AMSU-B in delineating structure of WDs. In particular, the cold intrusion and the moist conveyor belts are examined. It was found that the multi-channel view of the AMSU-B permits a better understanding of the moist structures seen in the conveyor belts. The α trous wavelet transform is used to clearly bring out mesoscale features in WDs. AMSU-B brings out intense convection as a large depression of BTs (<62>50K) at 150/176 GHz, cirrus and moist bands at 180/182 GHz. Mesoscale convection lines within WDs that last short time are shown here for the first time only in the AMSU-B images. Large-scale cirrus features are separated using the αtrous wavelet transform. Lastly, it is shown that there is a good likeness in the rain contours in the 3-h rain 3B42 (computed from TRMM and other data) to AMSU-B depressions in BT. Overall, AMSU-B shows better skill in delineating the structure of clouds and rain in WDs.

9 illus, 16 ref

003618   Pruseth K L (Institute Instrumentation Centre, Indian Institute of Technology Roorkee, Roorkee-247 667) : Calculation of the CIPW norm: new formulas. J Earth Syst Sci 2009, 118(1), 101-13.

Completely new set of formulas,based on matrix algebra,has been suggested for the calculation of the CIPW norm for igneous rocks to achieve highly consistent and accurate norms. The suggested sequence of derivation of the normative minerals greatly deviates from the sequence followed in the classical scheme. The formulas are presented in a form convenient for error-free implementation in computer programs. Accurate formulas along with the use of variable molecular weights for CaO and FeO; corrected formula weights for apatite, pyrite and ?uorite; and suggested measures to avoid signi?cant rounding o? errors to achieve absolute match between the sum of the input weights of the oxides and the sum of the weights of the estimated normative minerals. Using an analogous procedure for determining the oxidation ratios of igneous rocks as used in the SINCLAS system of Verma et al (2002, 2003), the suggested calculation scheme exactly reproduces their results except for apatite for reasons explained in the text, but with a superior match between the totals for about 11,200 analyses representing rocks of a wide range of composition.

30 ref

003617   Praveen K R;Prasannakumar V;Mamtani M A (Geology Dep, University of Kerala, Kariavattom, Trivandrum-695 581, Email: geopraveen@gmail.com) : Time relationship between regional deformation and fabric development in the Peralimala Pluton, south India - inferences from magnetic fabric. J Geol Soc India 2009, 73(6), 803-12.

Anisotropy of magnetic susceptibility (AMS) is investigated in samples of Peralimala (PM) pluton (ca. 550 Ma) and adjacent gneiss, gabbro, mylonite and amphibolite from the Moyar Shear Zone (MSZ), Southern Granulite Terrane (SGT) with an aim to decipher the time-relationship between fabric development in the pluton and regional tectonics. Magnetic foliation recorded in the PM pluton is sub-parallel to the WNW-ESE striking MSZ. Magnetic foliation and lineation trajectories are sigmoidal and curve into the shear zone. A dextral sense of shear is deciphered from the trajectories, which is similar to that reported within the MSZ in some earlier studies. It is inferred that the PM pluton has developed post-emplacement deformation-fabric related to reactivation of the MSZ during Pan-African age. Based on the data and existing information about regional tectonics of the area, the possibility of the (a) PM pluton being a Deformed Alkali Rock and Carbonatite (DARC) and (b) MSZ marking an ancient suture zone, is discussed.

8 illus, 1 table, 44 ref

003616   Pavithran S;Ingole B S;Nanajkar M;Raghukumar C;Nath B N;Valsangkar A B (NO, National Institute of Oceanography (CSIR), Dona Paula, Goa-403 004) : Composition of macrobenthos from the Central Indian Ocean Basin. J Earth Syst Sci 2009, 118(6), 689-700.

Deep sea is well known for its high faunal diversity. But the current interest in its abundant polymetallic nodules, poses a threat to the little known benthic organisms surviving in this unique environment. The study is the first attempt to document the Indian Ocean abyssal benthic diversity of macroinvertebrates and to investigate its relation to the surface primary production (chl-a), sediment labile organic matter, organic carbon and texture. The study is based on 87 individuals. Altogether 39 macroinvertebrate genera were obtained from water depths of 4500-5500m from 23 box cores. Reduction in macrobenthic density was seen towards the southern latitudes. The area was dominated by deposit feeding macrobenthos. Vertically, the fauna was distributed down to 30 cm depth, with the highest faunal density in the top 2-5 cm sediment section. The values for population density were strongly correlated with surface water chl-a and sediment protein, indicating supply of fresh organic matter as a critical factor for maintaining the deep sea benthic diversity and abundance.

7 illus, 3 tables, 55 ref

003615   Patil Anil R;Lohar Prakash S (NO, Dr. P.M.V. College, Washivali-410 220) : Seasonal variations in physico-chemical parameters of river Patalganga, Raigad district, Maharashtra. J Aquatic Biol 2009, 24(2), 109-12.

Patalganga river is the most important river of Raigad district in Maharashtra. It originates from the Sahyadri mountains to the east and flows westwards to meet Arabian sea through Dharamtar creek. Patalganga river supplies water for irrigation, drinking and industrial zone. Water samples were collected form three different sites along the river. Physical and chemical parameters were studied during June 2008 to May 2009. The river receives much of the industrial waste while passing through the industrial zone and hence there is much more deterioration of the water quality, and pollution of the aquatic environment. There is an urgent need of an action plan for conservation of the river.

1 illus, 2 tables, 11 ref

003614   Pandey D K;Tej Bahadur (Geoloy Dep, University of Rajasthan, Jaipur-302 055, Email: dhirendrap@hotmail.com) : Review of the stratigraphy of Marwar supergroup of west-central Rajasthan. J Geol Soc India 2009, 73(6), 747-58.

The lithostratigraphy, depositional environment and age of the Marwar Supergroup have been reviewed in the light of report of δ¹³C depletion recorded in the carbonates of the Bilara Group (middle part of Marwar Supergroup) and discovery of trilobite-like trace fossils from the "Red beds" of Nagaur Group (Upper part of Marwar Supergroup). The δ¹³C depletion observed in Bilara carbonates is not a result of glaciation rather due to rapid burial and poor water circulation in the low energy water of the protected basin. Secondly, the trace fossils are, in fact, traces of notostracan crustaceans found in shallow fluvial and shallow lacustrine environment. The paper also records a spiral, burrowing trace-fossil, posible Gyrolithes, from a cross-bedded sandstone of the Jodhpur Group.

2 illus, 1 table, 79 ref

003613   Pal T;Deb M (Geology Dep, University of Delhi, Delhi-110 007) : Breithauptite: a rare antimonide in the Dariba-Rajpura-Bethumni Belt, Rajsamand district, Rajasthan. J Geol Soc India 2009, 74(1), 35-8.

Breithauptite (NiSb), a rare antimonide, is generally found associated with hydrothermal vein ores of Ni and Co. In India, it has so far been recorded only from the gold-quartz veins of the Kolar Gold Field. Occurrence of this antimonide in a sediment-hosted milieu however, has seldom been noted. Reports the identification and characterization of this rare phase in both the stratiform and the vein-type ores of the sediment-hosted Zn-Pb sulphide deposits and prospects within the Dariba-Rajpura-Bethumni metallogenic belt in Northwestern India. Metamorphic remobilization from the stratiform ores of the belt has been postulated as a possible mechanism for the conspicuous segregation of breithauptite as a discrete phase within these ores.

2 illus, 2 tables, 10 ref

003612   Negi H S;Thakur N K;Rajeev Kumar;Manoj Kumar (NO, Snow and Avalanche Study Establishment, Him Parisar, Sector-37A, Chandigarh-160 036, Email: negi_hs@yahoo.com) : Monitoring and evaluation of seasonal snow cover in Kashmir valley using remote sensing, GIS and ancillary data. J Earth Syst Sci 2009, 118(6), 711-20.

Seasonal snow cover is a vital natural resource in the Himalaya. Monitoring of the areal extent of seasonal snow cover is important for both climatological studies as well as hydrological applications. Snow cover monitoring was carried out to evaluate the region-wise accumulation and ablation pattern of snow cover in Pir Panjal and Shamshawari ranges of Kashmir valley. The study was carried out for the winter period between November and April of 2004-05, 2005-06 and 2006-07, using multi-temporal WiFS sensor data of IRS-1C/1D satellites. The study shows reduction in the areal extent of seasonal snow cover and rising trend of maximum temperature in three winters for the entire Kashmir valley. This has been validated with 20 years (1988- 89 to 2007-08) climatic conditions prevailed in both ranges of Kashmir valley. Region-wise study shows the spatial and temporal variability in seasonal snow cover within Kashmir valley. Advance melting was observed in Banihal and Naugam/Tangdhar regions than Gurez and Machhal regions. Different geographical parameters of these regions were studied to evaluate the influence on snow cover and it was observed that altitude and position of region with respect to mountain range are the deciding factors for retaining the seasonal snow cover for longer duration. Such region-wise study of snow cover monitoring, can provide vital inputs for planning the hydropower projects, development in habitat areas, recreational and strategic planning in the region.

6 illus, 3 tables, 31 ref

003611   Negi H S;Kulkarni A V;Semwal B S (NO, Snow and Avalanche Study Establishment, Chandigarh-160 036) : Estimation of snow cover distribution in Beas basin, Indian Himalaya using satellite data and ground measurements. J Earth Syst Sci 2009, 118(5), 525-38.

In the study a methodology has been developed for the mapping of snow cover in Beas basin, Indian Himalaya using AWiFS (IRS-P6)satellite data. The complexities in the mapping of snow cover in the study area are snow under vegetation, contaminated snow and patchy snow. To overcome these problems, field measurements using spectroradiometer were carried out and reflectance/snow indices trend were studied. By evaluation and validation of different topographic correction models, it was observed that, the normalized difference snow index (NDSI) values remain constant with the variations in slope and aspect and thus NDSI can take care of topography efects. Different snow cover mapping methods using snow indices are compared to find the suitable mapping technique. The proposed methodology for snow cover mapping uses the NDSI (estimated using planetary reflectance), NIR band reflectance and forest/vegetation cover information. The satellite estimated snow or non-snow pixel information using proposed methodology was validated with the snow cover information collected at three observatory locations and it was found that the algorithm classify all the sample points correctly, once that pixel is cloud free. The snow cover distribution was estimated using one year (2004 -05) cloud free satellite data and good correlation was observed between increase/decrease areal extent of seasonal snow cover and ground observed fresh snowfall and standing snow data.

7 illus, 6 tables, 39 ref

003610   Nayak L;Behera D P;Mohapatra R;Swain D (Marine Sciences Dep, Berhampur University, Bhanja Bihar, Berhampur-760 007) : Bhitarkanika mangrove forest: a sensitive fragile ecosystem. Nat Envir Pollut Technol 2009, 8(1), 43-7.

Out of 110 species of mangroves, identified on the globe, 63 species are found in Bhitarkanika. The mangroves support marine life of 60 genera and 64 species of microfauna, 34 genera and 55 species of meiofauna, 19 species of amphibians, 42 species of reptiles including the rare and endangered sea turtle, more than 200 species of birds, 60 species of mammals, and 6 species of marine mammals. Three hundred species of fishes and 229 species of crustaceans also inhabit this sanctuary. The wild animals such as leopard, cat, fishing cat, jungle cat, hyena, wild boar, spotted dear, sambar, porcupine, python, dolphin, king cobra, salt water crocodiles, water monitor lizard, terrapins, common mongooses, Indian field mouse, and Indian mole rat are living in this sanctuary. The water temperature of the sanctuary varied from 25°C to 32°C, and air temperature from 28°C to 36°C. The pH value ranged from 6.98 to 8.7. Salinity fluctuated from 9 ppt to 33.8 ppt. The dissolved oxygen ranged from 2.325 mg/L to 7.250 mg/L, carbonate alkalinity from 25 mg/L to 60 mg/L, and bicarbonate alkalinity from 65 mg/L to 120 mg/L.

3 tables, 15 ref

003609   Nath A;Manohar G K;Dani K K;Devara P C S (NO, Indian Institute of Tropical Meteorology, Pune-411 008) : Lightning activity over land and oceanic regions of India. J Earth Syst Sci 2009, 118(5), 467-81.

Monthly variations of lightning activity over typical land and oceanic regions of India were examined using satellite data (OTD) for a 5-year period (1995 -1999). It is noted that the nature of variation between surface air maximum temperature (T_max, thunderstorm days (Th_n, and lightning flash count over ER and WR showed remarkable correspondence and sensitivity with each other on monthly time scale. As we move out of winter season and enter the monsoon season, via pre-monsoon season, the WR undergoes cooling relative to the ER in the range 0.1 -1.2° C. As a result, WR experiences reduction of thunder days and lowering in ?ash count. This decrease in T_max Th_n and flash count over WR may also be associated with relatively small values of T_θw and CAPE in comparison with similar values over ER during the monsoon season. Observation of associated reduction in Th_n and lightning count per 1 °C cooling in surface air maximum temperature suggests reduction of <126>3.5 thunderstorms per station and 73 flashes. Comparison of lightning ?ashes between pairs of coastal, oceanic, arid-zone, hilly, and island stations reveals distinct relationship between climate regime and intensity of lightning activity. It is concluded that the results of the study by saying that the overhead lightning activity is a clear reflection of the status of the underlying ground-earth properties. A close and continuous monitoring of lightning activity may be considered as a need of present day scientific studies.

10 illus, 5 tables, 51 ref

003608   Nataraja S;Purushothama R;Manjunatha R (Botany and Environmental Science Dep, Sahyadri Science College, (Autonomous), Shivamogga-577 201) : Nutrient status of Tunga river, Shivamogga, Karnataka. J Aquatic Biol 2009, 24(2), 113-7.

In the investigation an attempt has been made to asses the extent of chemical status in Tunga river, for this-two stations were selected for the sampling methods i.e., S₁ and S₂ the main aim of the study was to determine the pollution status of Tunga river and the suitability of the water for domestic and other purposes, in the light of water quality criteria prescribed by ISI standards. The results reveled that the values of chemical status DO, CO₂ and magnesium do not compile with ISI standards.

3 tables, 8 ref

003607   Nanda J;Gupta S;Mamtani M A (Geology and Geophysics Dep, Indian Institute of Technology, Kharagpur-721 302) : Analysis of deformation fabric in an alkaline complex (Koraput): implications for time relationshp between emplacement, fabric development and regional tectonics. J Geol Soc India 2009, 74(1), 78-94.

Koraput Alkaline Complex (KAC) lies on the NE-SW trending Sileru Shear Zone (SSZ) separating the Proterozoic Eastern Ghats Province from the Archaean Indian craton. The core of the KAC is made of hornblende gabbro, which is rimmed by a band of nepheline syenite in the east and syenodiorite in the west. The timing of magmatism with respect to the SSZ is disputed. The KAC was deformed during emplacement, and a magmatic foliation related to the syn-emplacement deformation, D₁, is present in the gabbroic core. The dominant D₂-related field fabric strikes NE-SW and is penetrative in parts of the gabbro and marginal lithologies. E-W trending D₃ shear zones cut across the complex. Distinct textural domains resulted from strain partitioning during deformation. Parts of the complex with magmatic textures constitute Domain-1, while D₂ and D₃ fabric zones comprise Domains-2 and 3 respectively. Temperatures in the KAC initially decreased following D₁, but increased through D₂ and D₃. Anisotropy of magnetic susceptibility (AMS) studies show that the magnetic fabric generally follows S₁ in Domain-1. While the magnetic fabric in Domain-2 is dominantly parallel to S₂, some of it parallels S₁. The latter is a relict D₁ fabric that is recognized from AMS analysis but is obliterated in the field, which confirms that the KAC pre-dates the SSZ. The response of magnetic fabrics to temperature and implications of the study for Indo-Antarctica amalgamation are discussed.

9 illus, 1 table, 69 ref

003606   Naithani A K;Bhatt A K;Krishna Murthy K S (NO, National Institute of Rock Mechanics, Kolar Gold Fields-563 117, Email: ajay_naithani@hotmail.com) : Geological and geotechnical investigations of Ioharinag-Pala hydroelectric project, Garhwal Himalaya, Uttarakhand. J Geol Soc India 2009, 73(6), 821-36.

The project area, forming a part of Bhagirathi valley, exposed rocks classed as central Himalayan crystallines and are medium to high grade metamorphics. The rock types exposed are feldspathic gneisses, quartz-biotite schists, gamet-biotite schist, biotite gneisses, migmatites and amphibolites. To design the rock support for the underground structures of desilting chambers, HRT, surge shaft, pressure shafts, power house, TRT and for the foundations of barrage and intake of desilting chambers, rock mass classifications was attempted following the methods of Bieniawski Rock Mass Rating (RMR) Classification and Tunnelling Quality Index (Q) of Barton et al. RMR technique involves collection of data on rock strength, RQD (%), spacing of discontinuities, condition or discontinuities and groundwater condition, while the 'Q' involves collection of data on RQD (%),joint set numbers (In),joint roughness number (Jr),joint alternation number (Ja),joint water reduction factor (Jw) and stress reduction factors (SRF). The permeability test in the overburden was done by the constant head method, while in the bed rock portion conducted by packer test. The result indicates that the rock masses of the area fall under the good, fair and poor rock quality. Augen gneiss of power house area is coming under the category of moderately strong rock as proved by deformability characteristics and strength parameter. On the basis of above study recommendations have been made for the proper and safe construction of the project components.

7 illus, 8 tables, 21 ref

003605   Nagaraju D;Papanna C (Studies in Geology Dep, University of Mysore, Manasagangotri-570 006) : Hydrogeochemical studies of Kabini river basin, Karnataka, India. Nat Envir Pollut Technol 2009, 8(1), 111-18.

Quality of ground water in the Kabini river basin, covering an area of 7040 sq km2 in Karnataka, has been studied based on the composition of one hundred sixty one borewell water samples. An attempt has been made to classify the ground water by various methods. According to Bureau of Indian Standards, 97% of the water samples in the study basin are within the desirable to permissible limit. 93% of the samples fall in C2-S1 class of USSL diagram. According to Wilcox diagram, 91% of samples fall within the excellent to permissible classes. In the Hill-Piper diagram, majority of the groundwater samples fall in the Ca, Mg-CO₃, HCO₃, and Na, K-CO₃, HCO₃ hydrochemical facies. This has been attributed to highly weathered and fractured nature of the basement rocks. By plotting on modified Hill-Piper diagram, it is found that majority of the samples have non-carbonate hardness with a salinity ranging from 2.5 to 23 epm. It is inferred that groundwater of the area has low sodium hazard and low to medium salinity. The range of dissolved components, the values of SAR and residual sodium carbonate indicate that 97% of the water samples of the basin are suitable for domestic, irrigation and industrial purposes.

7 illus, 1 table, 10 ref

003604   Murthy B S;Latha R;Sukumaran C;Shivaji A; Sivaramakrishnan S (NO, Indian Institute of Triopical Meteorology, Dr Homi Bhabha Road, NCL Post, Pune-411 008, Email: murthy@tropmet.res.in) : Influence of spatial heterogeneity on an internal boundary layer at a short fetch. J Earth Syst Sci 2009, 118(1), 61-70.

Surface layer meteorological data collected at a coastal site, at Vasco-Da-Gama (15°21'N, 73°51'E, 58.5m MSL) (13-18 July, 2002) with prevailing southwesterly surface winds are analyzed to study the characteristics of internal boundary layer at a short fetch using an instrumented tower (9 m). The spectral and turbulence characteristics of wind are compared with earlier measurements made at a comparatively homogeneous terrain and the standards available in literature. The study show the smaller eddies in the vertical velocity spectrum attains equilibrium with the underlying surface at a short fetch itself and follows spectral similarity. However, this is not followed by longitudinal and transverse velocity spectra under unstable as well as stable conditions.

7 illus, 4 tables, 17 ref

003603   Mukhopadhyay P;Mahakur M;Singh H A K (Forecasting Research Div, Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pune-411 008, Email: mpartha@tropmet.res.in) : Interaction of large scale and mesoscale environment leading to formation of intense thunderstorms over Kolkata Part I: Doppler radar and satellite observations. J Earth Syst Sci 2009, 118(5), 441-66.

Weather systems that predominantly affect the eastern and northeastern parts of India during the pre-monsoon summer months (March, April and May) are severe thunderstorms, known as Nor 'westers. The storms derive their names from the fact that they frequently strike cities and towns in the southern part of West Bengal in the afternoon from the north-west direction while traveling far from its place of genesis over the Bihar plateau. The storms are devastating in nature particularly due to strong (gusty) winds, heavy rains and hails associated with it. Although these storms are well known for its power of causing damages, studies on them are relatively few due to their small size and sparse network of observations. To address this important issue, the evolution of two Nor 'westers of 12 March and 22 May 2003 over Kolkata is studied in detail using hourly Doppler weather radar (DWR) observations and high resolution Meteosat-5 imageries. In addition, supporting meteorological reports are used to find the large scale conditions that influence the moisture convergence and vertical wind shear. The genesis of both the storms is found to be over Bihar-Jharkhand region and beyond the range of the DWR. The satellite observations are found to be useful in identifying the location and initiation of the storms. The movements of the storms are captured by the DWR estimated vertical cross-section of reflectivities. The Doppler estimate shows that the 12 March storm had a vertical extent of about 10 -12 km at the time of maturity and that of 22 May reaching up to 18 km signifying deep convection associated with these events. The genesis, maturity and dissipation are well brought out by the hourly DWR and satellite imageries. The DWR observations suggest that the systems move at a speed of 20 -25 m/s. The DWR estimated precipitation shows a detailed spatial distribution around Kolkata with several localized zones of heavy rain and this is found to be well supported by the nearby station observations. The study establishes that DWR observations along with hourly satellite imageries are able to capture the evolution of Nor 'westers. The study also shows that the composite DWR-satellite information is a reliable tool for now casting the location, time and path of movement of Nor 'westers.Based on these observations,a conceptual model of the Nor 'wester is proposed.

18 illus

003602   Mishra V D;Sharma J K;Singh K K;Thakur N K; Kumar M (NO, Snow and Avalanche Study Establishment, Chandigarh-160 036, Email: vd_mishra@rediffmail.com) : Assessment of different topographic corrections in AWiFS satellite imagery of Himalaya terrain. J Earth Syst Sci 2009, 118(1), 11-26.

Influence of topographic effects in optical satellite imagery is not investigated very extensively in the Himalayan terrain. The topographic variability causes a problem of differential illumination due to steep and varying slopes in rugged Himalayan terrain. Therefore, topographic corrections are essential for qualitative and quantitative analysis of snow cover applications. Discusses the implementation of different topographic correction models on AWiFS sensor onboard IRS P6 satellite images and the qualitative and quantitative comparative analysis in detail. Both the Lambertian and non-Lambertian assumptions have been considered in the present analysis with the aim to explore best suitable empirical model for rugged terrain.

10 illus, 4 tables, 39 ref

003601   Menon R;Sunder Raju P V;Reddy G K (NO, National Geophysical Research Institute (CSIR, Hyderabad-500 007) : Soil-geochemistry, radiometric and soil gas helium studies in the uranium mineralized zone of Tumallapalle, Cuddapah Basin, Andhra Pradesh. J Geol Soc India 2009, 74(1), 23-6.

Geochemical soil sampling survey undertaken at Tumallpalle uranium mineralized zone Cuddapah district, has confirmed the presence of uranium anomalies in soils. Bulk soil samples were collected at every 20 m along the traverse from approximately 30 cm below the surface and were assayed for uranium by x-ray fluorescence (XRF) and inductively coupled plasma mass spectrometry (ICP-MS). The uranium anomalies detected by the insitu radiometric survey show a correlation with the helium highs. The soil gas helium studies have aided in delineating the subsurface extension of the deposit. The study endeavors for an integration of different techniques in a known area which could probably aid in delineating uranium zones for optimal exploitation in the future exploration programmes.

3 illus, 10 ref