016983   Salvekar P S;Mishra S K (NO, Indian Institute of Tropical Meteorology, Pune) : Effect of Ekman boundary layer friction on the baroclinic growth of monsoon depression. Mausam 2001, 1(1), 203-08.

Linear baroclinic stability analysis of the mean monsoon zonal flow for varying vertical shear in the boundary layer is performed by using an adiabatic, quasi-geostrophic, 25-layer, numerical model with Ekman boundary layer friction. It is found that Ekman friction reduces the growth rates in the short wave region (L≤3000 km). It is important to note that the friction plays a crucial role in the selection of the short preferred wave. In order to find the effect of friction explicitly, the vertical structures of the viscus and inviacid preferred waves are computed. It is concluded that the effect on the vertical structure of wave amplitudes is proportional to the wind shear below the basic westerly wind maximum. The vertical tilts of the wave as well as vertical extension are increased due to friction. Further, it is noticed that the friction induces direct circulation in the lower layers.

6 illus, 1 table, 11 ref

016982   Ruj B (Department of Chemistry, Central Mechanical Engineering Research Institute, Durgapur) : Water quality and corrosivity of ground water of northwestern part of Bankura district, West Bengal. J envir Pollut 2001, 8(4), 329-32.

Survey was undertaken to assess the quality of ground water in the northwestern part of Bankura district of West Bengal, taking both physical and chemical parameters into consideration. Relevant parameters like, pH, total hardness, Cl^-, free CO2, alkalinity, conductivity, DO, TDS, SO4⁼, iron, calcium, magnesium and arsenic were determined. It was observed from the study that 78% of the water samples from tube wells exceeds the limit permissible for portable water with respect to iron. The nature of corrosivity of ground water was also determined.

1 illus, 3 tables, 5 ref

016981   Rao M S V (NO, Meteorological Office, New Delhi) : Mean meridional air-motion and associated transport processes in the atmosphere. Mausam 2001, 1(1), 35-60.

Eliassen's equation of quasi-static balance has been re-derived in a more suitable frame of co-ordimates and, by making certain simplifying assumptions, rendered into a form which lendsitselfeasily to solution by relaxation. The differential equation thus obtained is solved for extended sources of heat and momentum similar to those actually encountered in the troposphere. The results show a mean meridional eireulation consisting of a strong direct cell in low latitudes and a weak indirect cell in middle latitudes. Starting from the idea that the mean meridional circulation is split up into cells and making use of the values of the strength of the circulation deduced by Tucker and Mintz, the sources and sinks of heat and momentum necessary to maintain such mean motion are evaluated. Further, an attompt is made to infer what the character of eddy motion in the meridional plane has to be in order to satisfy balance requirements.

18 illus, 1 table, 20 ref

016980   Rajamani S (NO, Indian Institute of Tropical Meteorology, Pune) : Energetics of the monsoon circulation over south Asia. II. Energy terms and energy transformation terms. Mausam 2001, 1(1), 195-202.

Study has been made of available potential energy and its transformation into kinetic energy of the different weather systems for the region of south Asia for the typical monsson month of July 1963. Energetics of the standing eddies and transient eddies have been separately computed. Interactions amongst themselves and with mean zonal flow have been studied. It is inferred that zonal current is the source of available potential energy for both standing and transient eddies; standing eddy is the source of kinetic energy for zonal current and transient eddies. However, when the region of monsoon depressions in strengthening the monsoon trough. Available potential energy is converted into kinetic energy in the cases of both zonal current and the standing eddy. The generation of available potential energy and the energy advected into the area of interest, together exceed the losses due to dissipation of kinetic energy.

2 illus, 2 tables, 18 ref

016979   Rajamani S (NO, Indian Institute of Tropical Meteoralogy, Pune) : Energetics of the monsoon circulation over south Asia. I. Diabatic heating and the generation of available potential energy. Mausam 2001, 1(1), 189-94.

Considering the monsoon circulation as the mean zonal flow with standing or stationary eddies (monsoon trough etc) and the transient eddies (monsoon depressions, lows etc) superimposed on it, diabatic heating and generation of available potential energy over south Asia have been computed for the typical monsoon month of July 1963, based on the computations of vertical velocity from omega-equation, and thermodynamic energy equation. Regions of upward vertical velocity are found to be areas of good rainfall. Rate of monthly mean diabatic heating in the troposphere is of the order of 0.5 deg. C and is higher at 500 and 300 mb levels than at lower levels. Positie generation of both zonal and standing eddy available potential energy is inferred.

4 illus, 1 table, 6 ref

016978   Prasad M (Regional Research Laboratory (C.S.I.R), , Hoshangabad Road, Near Habibganj Naka, Bhopal-462 006) : Rock phosphate deposits of Madhya Pradesh : present status and future prospects. Fertil News 2002, 47(2), 25-8,31.

Rock phosphate is the critical raw material in the manufacture of phosphatic fertilizers. Out of 145 million tonnes (MT) of recoverable reserves of rock phosphate approximately 13.5 MT only have been estimated to be of high grade p(+ 30% P2O5)) which are being mined by different government agencies for commercial purposes. The beneficiable grade (11-20% P2O5) are estimated to be 81.2 MT while the low grade reserves of rock phosphate are estimated to be 19 MT. The depletion of high grade phosphate ores has brought about a search for suitable economically viable technique/process for beneficiating available low grade phosphate reserves. The total reserves of rock phosphate in Madhya Pradesh are 36 MT. Except some recent efforts by RRL, Bhopal, no attempt has been made to beneficiate the low grade rock phosphate of Madhya Pradesh through an economically viable process. The exploitation of these beneficiable grade deposits is of immense importance to our country since it will increase the contribution of indigenous marketable grade of P2o5.

2 illus, 2 tables, 8 ref

016977   Prasad A S S S R S;Sarkar D;Reddy P R (National Geophysical Research Institute, , Hyderabad-500 007) : Identification and usage of multiples in crustal seismics - an application in the Bengal Basin, India. Curr Sci 2002, 82(8), 1033-7.

Multiple seismic phases associated with deeper horizons have been observed in long-range seismic refraction sections. These have been successfully distinguished from the primary events and utilized to build crustal velocity-depth section along Gopali-port Canning profile, Bengal Basin.

6 illus, 13 ref

016976   Pavanaguru R;Narsing Rao A;Vijaya Kumar J; Reddy M N (Geology Department, Osmania University, Hyderabad-500 007) : Geoscientific considerations and its impact on the environment - Kothagudem area. J envir Pollut 2000, 7(3), 189-95.

The universally famed cryptic/banded anorthosites of Archaen age with mega-lineations and gneissosity, the pakhal meta-sedimentary suits comprising metamorphosed dolomites/tremolite-marble/quartzites and phyllites with emplacement of quartz concentrations have been considered in the context of delineation of environmental issues. The multifold increase in the exploitation of coal from Godavari Valley Coat Belt (GVCB) from 4 M.T. (1969-70) to about 29 M.T. (1998-99) is also met partly from this area, warranting evaluation of the geological, geochemical and associated ingredients of coal/formations having a bearing on the environment. The modal composition, the heavy mineral constituents of litho-units of Gondwana formations, and the nature and type of banded coal with inherent/extraneous mineral matter suggest the chemical nature of suspended particulates generated during the course of exploitations. Significant abundance of trace elements viz., Co, Cr, Mn, Ni, V, Zr, Cu, Pb, Ba, Sr and Ga have been obtained in this area. However, detailed chemical data on these horizons are scanty. The mine water and groundwater characteristics are varied and appear to have faciliatated differential elemental migration in the exogenic environment. Though attempts of major Organisms and Government agencies to identify the efforts of redressal for the restoration of the environment are in the offing.

1 illus, 5 tables, 11 ref

016975   Patro S K (Department of Marine Sciences, Berhampur University, Berhampur-760 007) : Nature of biogenic elements in the surface sediments of the eastern continental shelf of India. J envir Pollut 2001, 8(4), 385-9.

Nature and distribution of biogenic elements in the shelf sediment of the East Coast of India have been evaluated. Better correlation of clay is observed with total nitrogen in comparison to total phosphors and organic matter, whereas organic matter has better relationship with total nitrogen and total phosphorus.

^ssc1 table, 30 ref

016974   Mudholkar A V;Kodagali V N;Kamesh Raju K A; Valsangkar A B;Ranade G H;Ambre N V (National Institute of Oceanography, , Dona Paula, Goa-403 004) : Geomorphological and petrological observations along a segment of slow-spreading carlsberg ridge. Curr Sci 2002, 82(8), 982-9.

One hundred and twenty km long section of the Carlsberg Ridge has been mapped with multi-beam bathymetry system (MBS). High resolution bathymetric contour map generated with the MBS data shows well-defined axial valley bordered by steep valley walls and the presence of a ridge axial discontinunity in the south-east end of the survey area. This discontinuity represents the propagating ridge head present along the ridge axis and is being reported for the first time along an active ridge segment of the Carlsberg Ridge. The pseudo-side scan image reveals a well-sedimented axial valley. It is for the first time that various upper mantle (serpentinites and peridotites) and lower crustal rocks (gabbros) have been recovered from this part of the Carlsberg Ridge apart from the ridge basalts. The basaltic rocks are mostly fresh; however a few types of basalt exhibit alteration. Serpentinites and peridotites are almost totally altered and exhibit the stress they have undergone during and after the emplacement.

^iia8 illus, 1 table, 29 ref

016973   Mohanty U C;Dube S K;Sinha P C (Centre for Atmospheric and Fluids Sciences, Indian Institute of Technology, New Delhi) : Role of Large scale energetics in the onset and maintenance of summer monsoon. II. Moisture budget. Mausam 2001, 1(1), 179-88.

Efect of large scale moisture and moist static energy (MSE) budget on the onset and activities of summer monsoon is investigated. The data base for this study consists of twice daily First GARP Global Experiment (FGGE) level IIIb analysis of temperature, relative humidity, gropotential and wind fields for a tropical belt from 20 deg. S to 40 deg. N and 0 deg. E to 150 deg. E, during May-July 1979. The daily variation, vertical distribution and period averages of the various terms in latent heat energy (LHE) and MSE budget equation are closely examined to find out their influence on the activities of monosoon. Indicates significant increase in the net LHE, horizontal convergence of moisture and diabatic moisture sink (indicator of excess condensation than evaporation) about two week before the onset of monsoon over Kerala coast. Further, a decreasing trend is observed in horizontal convergence of moisture and moisture sink about one week before the break monsoon condition, which started over India on 16 July 1979. However, the various terms of the MSE budget equation do not depict any significant trend with the advance of the monsoon. The vertical distribution, period averages and the boundary fluxes also confirm the above findings.

6 illus, 7 ref

016972   Mohanty U C;Dube S K;Sinha P C (Centre for Atmospheric and Fluids Sciences, Indian Institute of Technology, New Delhi) : Role of large scale energetics in the onset and maintenance fo summer monsoon. I. Heat budget. Mausam 2001, 1(1), 165-78.

Effect of large scale heat budget on the onset and activities of southwest Asian monsoon is studied for the tropical belt (20 deg 5.40 deg. N and 0 deg. H-150 deg. E). For this study the level-IIIb analysis of the First GARP Global experiment (FGGE) during May-July 1979 is utilised. The daily variation, vrtical distribution and period averages of the various terms in heat budget equation are closely examined to find out their influence on the activities of monsoon. It is found that there is significant increase in the net enthalpy, horizontal convergence of heat and diabatic heating about two weeks before the onset of monsoon over Kerala coast. It is further found that a decreasing trend in these values is observed about one week before the break monsoon condition, which started over India on 16 July 1979. The vertical distribution, period averages and the boundary fluxes also confirm the above fingings.

8 illus, 1 table, 28 ref

016971   Mathur M B (NO, National Center for Environmental Prediction, Washington D.C.) : Impact of parameterized convection on a numerically simulated tropical cyclone structure. Mausam 2001, 1(1), 251-72.

Central storm area remains conditionally unstable also in the fine mesh experiment in which the parameterized convective heating is excluded and the resolvable scale heating is evaluated at each time step. Intense vertical motion and vigorous heating develop indeep vertical columns, indicating that the heating on the convective scale is simulated as the resolvable scale heating. The vertical distribution of heating and the storm structure, during the first six hours in this case, are similar to those in the fine mesh run in which both condensational processes are evaluated at intervals of twelve time steps. However, the storm intensifies more rapidly after 6 h in the former than in the later case. Numerical results from additional experiments are presented to show that predicted stom structure is modified with a change in interval for invoking either or both condensational processes, and these circulation differences are not due to the initial spin up. Transfer of moisture and heat from low levels into the higher troposphere in cumulonimbus clouds takes place in several minutes. Above cited and other predictions from the QLM suggest that storm structure, intensity an dmotion in a measoscale model are likely to be improved when parameterized convective heating is included; however, a parameterization scheme that concurrently produces alterations in the entire model cloud depth should be invoked at intervals of several minutes.

16 illus, 2 tables, 23 ref

016970   Mandal J C (Regional Meteorological Centre, , Calcutta) : Numerical simulation of a tropical storm boundary layer. Mausam 2001, 1(1), 227-36.

Model has been designed to study the surface boundary layer of a tropical storm. The numerical method consists of solving a two point boundary value problem for two systems of simultaneous non-linear differential equations by finite differences. A stoke's stream function suitable to represent the flow both in interior and exterior regions of a tropical storm boundary layer has been developed. The advantage of the method is that the boundary layer of the tropical storm can be studied starting from the outer region to the centre of the storm without neglecting non-linear terms. In addition, there is no need for assumptions on the gertical profiles for tangential and radial velocities. The method is stable and converges within a few iterations. The flow above the friction layer is represented by a steady axisymmetric vortex in gradient balance. To investigate the effect of turbulence on boundary layer characteristics, turbulence has been represented by four different variations of the eddy coefficient of viscosity with no slip boundar conditions. Computations have been performed taking 40-grid points in the vertical dirction. It is observed that, if the eddy coefficient of viscosity is assumed to vary with the superimposed flow above the boundary layer, the solutions compare favourably well with observations. The solution also shows an outflow from the iner core of the boundary layer which is necessary for creation of an eye of the storm.

7 illus, 25 ref

016969   Mandal J C (NO, Meteorological Office, New Delhi) : Model of tropical storm from temperature anomaly distributions. Mausam 2001, 1(1), 209-16.

Simple equation has been formulated to find out the temperature anomaly distributions in axisymmetric steady state tropical storm from a few known values in the real storm and a method to find out the temperature anomaly distributions in axisymmetric steady state tropica storm from a few known values in the real storm and a method to find out the velocity and pressure distributions of storm from it. A few case studies with assumed typical distribution of anomaly field have been discussed. It has been found that in addition to horizontal distribution of anomaly field, strength fo the storm depends on its vertifcal distribution also. Profiles relating to the maximum temperature anomaly with maximum tangential velocity and that with minimum sea level pressure are also presented which have good agreement with typical real storms an dcan be readily used as a nomogram.

10 illus, 1 table, 7 ref

016968   Mahapatro T R;Padhy S N;Sahu B K (Department of Marine Science, Berhampur University, Berhampur-760 007) : Assessment of nutrients in the estuarine water of Rushikulya (Bay of Bengal), India. J envir Pollut 2001, 8(3), 221-4.

Assessment of nutrients in the estuarine water of Rushikulya has been made for a period of one year for evaluating quantitatively the extent of eutrophication using nutrient index (I). Water quality with respect to NO3-N was oligotrophic (I<60>3) in the estuarine zone (Stations 1 & 2), whereas it was mesotrophic (I<62> (I<62>3) towards riverine zone (Station 3, 4 & 5). The nutrient index for it showed an increasing trend from estuarine to riverine zone. It may be due to interruption of freshwater from river. Water quality with respect to PO4-P was oligotrophic (I<60>3) in all the stations where the nutrient index showed a decreasing trend upto station 3 as a result of land runoff near station 1. An increasing trend was observed from station 3 to station 5 attributing to river runoff. At station 3 minimum value was observed due to its intermediate position. Salinity and pH showed a decreasing trend from estuarine to riverine zone, whereas DO and BOD showed the reverse trend.

1 illus, 2 tables, 14 ref

016967   Mahapatro T R;Padhy S N (Department of Marine Sciences, Berhampur University, Berhampur-760 007) : Nutrients and physico-chemical characterisation of Rushikulya estuary during premonsoon. J envir Pollut 2001, 8(1), 61-5.

Studies on the physico-chemical parameters (salinity, temperature, DO, pH, BOD) and nutrients (NO3-N, PO4-P and SiO4-Si) in the Rushikulya estuary were made during the premonsoon season. Temperature varied from 25.6-26.9°C. pH (7.81-8.0) and salinity (15.14-25.96%) showed a decreasing trend from estuarine to riverine water. DO (6.2-8.6 mg/L) and BOD (0.79-1.86 mg/L) exhibited an increasing trend from estuarine to riverine water. Nutrient like NO3-N (0.609-2.176 μg/L) and SiO4-Si (16.013-25.673 μg/L) showed an increasing trend, whereas PO4-P (0.199-0.503 μg/L) showed a decreasing trend from estuarine to riverine water.

2 illus, 1 table, 20 ref

016966   Madhavi Latha G;Dash S K;Rajagopal K; Krishnaswamy N R (Department of Civil Engineering, Indian Institute of Technology, Madras, Chennai-600 036) : Finite element analysis of strip footing supported on geocell reinforced sand beds. Indian Geotech J 2001, 31(4), 454-78.

Finite element simulation of the bahaviour of geocell reinforced sand beds under strip loadings has been presented. A composite model has been proposed in this paper for numerically simulating the strength and stiffness behaviour of sand confined with geocell reinforcement. The accuracy of this method has been verified by comparing the finite element results with the corresponding experimental results. The comparison between the numercial results and the experimental results was found to be reasonably good. The finite element model was able to capture the influence of the height and width of geocell layer, pocket size, modulus of the geocell material and placement depth of geocell layer. The trends observed in the laboratory model tests were well replicated by the finite element model. This inducates that the proposed composite model is able to represent the behaviour of geocell mattress successfully.

17 illus, 1 table, 23 ref

016965   Kondragunta C R (NO, University of Hawaii, Honolulu) : Intraseasonal variations of the asiatic summer monsoon. Mausam 2001, 1(1), 217-26.

Intraseasonal fluctuations of the Asiatic summer monsoon are investigated using Outgoing Longwave Radiation (OLR) covering eight northern hemisphere summers (1 May to 30 September 1975-83, except 1978). The intraseasonal variance is large in the equatorial Indian Ocean and the northwest Pacific. OLR fluctuations in the equatorial Indian Ocean, over India and the northwest Pacific show spectral peaks on time scales 30-60 day, 10-20 day and less than 10 days. Reveals intraseasonal variation associated with the interannual variation. Over India below normal summer rainfally years are associated with 30-60 oscillation, near normal summer rainfally years are associated with 30-60 day and 10-20 day oscillations and above normal rainfall years are associated with oscillations less than 10 days. Empirical Orthogonal Function (EOF) analysis has been carried out for the whole Asiatic summer monsoon domain. The first four EOF coeficients explain 15% of the total variance. EOF analysis confirms existence of oscillations at least on three time scales, viz., 30-60 day, 10-20 day and less than 10 days over the Asian summer monsoon region.

5 illus, 27 ref

016964   Khole M;De U S (Meteorological Office, , Pune-411 005) : Floods and droughts in association with cold and warm ENSO events and related circulation features. Mausam 2001, 1(1), 13-22.

For the Indian subcontinent, the occurence of floods and droughts is closely linked with the summer monsoon activity. The phenomenon of E1 Nino-Southern Oscillation (ENSO) has been established to be one of the major teleconnections of Indian Summer Monsoon. Also the relationship between the circulation features and summer monsoon activity is well documented in the literature. The interaction of ENSO with monsoon system was known to the seasonal forecasters in India from the days of G. Walker. Normand (1953) summarising these results has remarked that `Monsoon has a proloned influence on the global weather rather than global weather parameters influencing the monsso'. 1990-94 was a prolonged period of warm ENSO producing weather anomalies in different regions of the globe. Yet during the same period all India rainfall was very close to normal and in fact, 1994 was a year of abundant rainfall for India. The aim of the study is to examine some of these features more critically. It is observed that ENSO has a modifying effect on the regional scale circulation pattern and possible interactions and/or phase-locking with the planetary scale circulation pattern, which results into the occurrence or non-occurrence of an extreme event. Also, a qualitative analysis is carried for a period 1960-90 to assess how far the mid-season rainfall deficiency is made up at the end of the season.

4 illus, 1 table, 18 ref

016963   Jade S;Malay M;Parvez I A;Anande M B;Dileep Kumar P;Gaur V K (CSIR Centre for Mathematical Modelling and Computer Simulation, , Belur Campus, Bangalore-560 037) : Estimates of coseismic displacement and post-seismic deformation using global positioning system geodesy for the Bhuj earthquake of 26 January 2001. Curr Sci 2002, 82(6), 748-52.

M_W = 7.6 Bhuj earthquake of 26 January 2001 that occurred in the Kachchh Rift Basin (KRB) was felt over a wide area in the country. Global Positioning System (GPS) measurements were made at eleven sites in the epicentral area and at Jamnagar, south of the KRB to estimate the total residual displacements at these sites as a result of this earthquake. During the survey, seven Great Trigonometrical Survey (GTS) points (1857) were reoccupied using GPS. An additional five GPS points were established by C-MMACS for post-seismic studies. The Jamnagar site was measured earlier in 1997 while the seven GTS sites are those established during the GTS, 144 years ago. Comparison of GPS (1997) and GPS (2001) coordinates at Jamnagar gives the coseismic displacement vector of 16± mm at N 35°E for the four-year period (1997-2001); this is the only GPS-GPS based estimate of coseismic slip of the Bhuj earthquake. Comparison of GTS sites yields upper bounds on the displacements suffered by these sites as a result of the co-seismic slip of major events that occurred in the intervening period. GTS (1857)-GPS (2001) baselines oriented at low angles to the NNE-SSW compression or transport direction have shortened in length, while those oriented at high angles have been elongated. The two epochs of measurements at the five GPS sites in KRB and Jamnagar during February and July 2001, yield post-seismic displacement rates averaging about 1 mm/month at these sites.

3 illus, 3 tables, 13 ref

016962   Heaman L M;Srivastava R K;Sinha A K (Department of Earth and Atmospheric Sciences, University of Alberta, Alberta T6G 2E3, Canada) : Precise U-Pb zircon/baddeleyite age for the Jasra igneous comples, Karbi-Analong District, Assam, NE India. Curr Sci 2002, 82(6), 744-8.

Five Cretaceous alkaline-carbonatite igneous complexes are reported from the Assam-Meghalaya Plateau. These alkaline intrusions have been interpreted to be coeval and associated with the 117-105 Ma Rajmahal-Sylhet flood basalt province. With the existing age information it is possible that the alkaline magmatism may be a late magmatic stage of the Rajmahal-Sylhet large igneous province. Therefore, it is essential to determine high-province. Therefore, it is essential to determine high-precision ages for these alkaline complexes in order to understand the detailed temporal evolution and genesis of this basaltic and alkaline magmatism. Out of five igneous complexes, Sung Valley, Swangkere and Samchampi have been dated, but the emplacement ages of the other two, i.e. Jasra and Barpung, are poorly constrained. Communication reports a new, high-precision U-Pb zircon/baddeleyite age for a differentiated portion of gabbro phase of the Jasra igneous complex.

3 illus, 2 table, 24 ref

016961   Godbole R V;Kelkar R R (NO, Institute of Tropical Meteorology, Poona) : Net terrestrial radiative heat fluxes over India during monsoon. Mausam 2001, 1(1), 79-88.

Infra-red radiative heat flux and instantaneous rate of temperature change have been computed for Indian sub-continent for monsoon season by making use of the numerical method developed for the purpose. The effects of water vapour alone have been considered. It is found that the radiative heat loss near the surface is minium over the Western Ghats. Over northeast and northwest India, the radiativeheat loss is relatively high. Also, the radiative cooling integrated from the surface upt 300 mb indicates a large cooling over northeast and northwest India (<62>1°C per day) and relatively small cooling over the southern Peninsula (<60>0.25°C per day). Analysis of the day-to-day values of net flux and temperature suggest no cause-and-effect relationship. However, a good correspondence has been noticed between net flux, temperature and total moisture content as far as surface level is concerned. The day-to-day values of net flux at higher levels follow very closely to those at the surface.

8 illus, 5 ref

016960   Ghosh S K (NO, Meteorological Office, Safdarjung Airport, New Delhi) : Prediction of storm surges on the east coast of India. Mausam 2001, 1(1), 137-48.

Nomograms to estimate peak storm surges genersted by tropical cyclones impinging on the east coast of India are prepared using Jelesnianski's SPLASH (1972) model. The pre-computed nomograns accommodate fixed values for pressure drop, radius of maximum wind, vector motion of storma and offshore bathymetry. Two sets of nomograms are presented - on for the northeast coast of India where the slope of the continental shelf is extremely shallow - the other for the remainin east coast where the slope in genral is extremely steep. A nomogram to correct the magnitude of the peak surgo for tidal effects is also prepared for the notheast coast of India where the semi-diurnal tide range is large. A method to estimate total sea level elevation along a coastal stretch by means of nomograms is given for the northeast coast of India.

20 illus, 1 table, 7 ref

016959   Ghose D;Chowdhury D P;Sinha B (Variable Energy Cyclotron Centre, , 1/AF Bidhan Nagar, Kolkata-700 064) : Large-scale helium escape from earth surface around Bakereswar-Tantloi geothermal area in Birbhum district, West Bengal, and Dumka district, Jharkhand, India. Curr Sci 2002, 82(8), 993-6.

Helium has been detected above the atmospheric background to levels of 2% in air at the surface within 1 m above the ground, in the Bakreswar-Tantloi geothermal area. The gas is released in periodic bursts. Soil air within shallow auger holes (75 cm deep) shows anomalous high helium concentrations at some locations. This communication describes details of the observed unusually large-scale helium escape through the earth's surface in the geothermal area and the experimental methods adopted for its quantitative confirmation.

3 illus, 3 tables, 16 ref

016958   Dube R K;Chattejee S N (NO, Meteorological Office, New Delhi) : Crustal structure of the Hindukush region. Mausam 2001, 1(1), 149-54.

Crustal structure beneath the Hundukush and adjoining region has been investigated using body wave data of near eathquakes. The crustal structure in the region has been found to consist of three layera: viz,. granitic 1, granitic 2 and basaltic layers. The velocitics in the three layers respectively of longitudinal and transverse scismic waves have been obtained as 5.32±0.03, 5.64±0.01 and 6.43±0.01 km/sec; and 3.28±0.002, 3.53±0.003 and 3.93±0.003 km/sec. The subcrustal velocities for longitudinal and transverse waves obtained are 9.13±0.01 and 4.53±5.5, 15.9±4.1 and 16.7±2.7 km respectively, making the average thickness of the crust as 50±11.9 km. It has been observed that the Mohorovicic discontinuity dips at an angle of 2' from north to south between Taskent and Quetta along 68°E (profile AB, Fig. 1). A dip of only 22' has been observed for the discontinuity between the points 37°N, 69°E and 44°N, 81°E (profile CD, Fig. 1). The thickness of the crust beneath Quetts has been obtained as 62±15.8 km.

5 illus, 6 tables, 13 ref

016957   Dimri A P;Mohanty U C;Madan O P;Ravi N (Centre for Atmospheric Sciences, Indian Institute of Technology, Delhi, Hauz Khasm New Delhi-110 016) : Statistical model-based forecast of minimum and maximum temperatures at Manali. Curr Sci 2002, 82(8), 997-1003.

Models for forecasting minimum and maximum temperatures have been developed for Manali in Himanchal Pradesh, for the months of December, January and February. These models are based on statistical techniques and use surface and upper air meteorological data from 1984 to 1989. The models are also tested with independent data and the results for 1995-96 are presented. The models yield good results with independent cases providing about 88% correct forecast with ±2°C of the observed values.

5 illus, 8 tables, 15 ref

016956   Dheenathayalu M;Ramasamy V;Barathan S; Venkatasamy V (Department of Physics, Annamalai University, Annamalainagar-608 002) : Mineral characterisation of some bauxitic nodular samples of Yercaud mines, Tamil Nadu, India. Acta Cienc Indica-Phys 2001, 27(3), 225-9.

FTIR technique was used as a tool to characterize the mineral content of bauxite nodular samples of Yercaud mines, Tamil Nadu. The ten different samples were collected from the mines and the KBr pellet technique was employed. The gibbsite, kaolinite, boehmite, haematite and quartz were identified as the mineral content of nodular specimen using their predominant i.r. absorption bands.

1 illus, 1 table, 14 ref

016955   Dheenathayalu M;Arumugam M;Ramasamy V (Department of Physics, Annamalai University, Annamalainagar-608 002) : Optical studies of Western Ghat granites of Tamil Nadu. Acta Cienc Indica-Phys 2001, 27(3), 179-82.

Quantitative estimation of minerals were done using thin section (optical) analysis. The thin sections were prepared for different samples collected at various heights of Nallamanaickerpatti hills, Tamil Nadu and subjected to optical studies using polarising microscope. Both qualitative identification and quantitative estimation of minerals were carried out using optical properties of the minerals. It was observed that the samples contained quartz, orthoclase, plagioclase, perthite as essential minerals and biotitie, magnetite and garnet as accessory minerals and illmenite, muscovite and apatite as trace minerals. The ability of studying the intergrowth of minerals was very well reflected using this method in the idenfitication of perthite mineral.

1 table, 8 ref

016954   Das P K (NO, Meteorological Office, New Delhi) : Lee waves associated with a large circular mountain. Mausam 2001, 1(1), 61-8.

Concerned with the baroclinic properties of stationary waves behind a large circular mountain. It is based on a linear, baroclinic model which includes the Coriolis force γ, and its variation with latitude β. The free stream velocity U and the stability parameter 1 is assumed to be independent of height. A wave equation is derived for the vertical component of perturbation volocity. Its asymptotic solution indicates that the wave amplitude is a function of the non-dimensional parameter (m=γL/lUd), where L and d are unit longths along the horizontal and vertical axes of reference. Numerical values of the solution are presented to indicate the attenuation of the wave with radial distance, with variations in m and with height.

2 illus, 1 table, 14 ref

016953   Chaudhury H M (NO, Meteorological Office, New Delhi) : Seismic surface wave dispersion and the crust across the gangetic basin. Mausam 2001, 1(1), 69-78.

Long Period seismograph records of Delhi of five earthquakes in the East Pakistan/Burma/India border region have been studied. The dispersion of fundamental and the second mode Rayleigh and Love waves and that of PL waves have been computed. Phase velocities of the fundamental Rayleigh and Love waves were also determined by using Brune's method. Inference regarding the structure of the crust across the Gangetic basin was made by comparison with known theoretical models as well as by using the partial derivatives of the phase velocities following Dorman and Ewing (1962), Brune and Dorman (1963) and Anderson (1964). One of the earthquakes included in its path to Delhi a part of the continental shelf. The close agreement of the group velocities of Rayleigh waves for this mixed path with those from the other earthquakes shows that the dispersion properties of the continental shelf involved are nearly the same as of the Gangetic basin. The results from the disparsion studies have been discussed with respect to the Geological and Geophysical results bearing on the subject.

10 illus, 3 tables, 21 ref

016952   Anvar Batcha S M (P.G. Department of Zoology, Jamal Mohamed College, Tiruchirappalli-620 020) : Distribution of organic matter content in the sediments of north Vembanad lake. J envir Pollut 2001, 8(1), 67-70.

Organic matter content of 216 sediment samples of north Vembanad lake were subjected to chemical analysis. The variations in organic carbon and organic matter percentage composition has been studied in 18 stations from December 1997 to December 1978 except August 1978. The differences in distribution of organic matter in different stations have been discussed with relation to the topography of the lake and position of the station with their locations.

1 illus, 17 ref

016951   Acharrya S K (Department of Geology, Jadavpur University, Kolkata-700 032) : Arsenic contamination in groundwater affecting major parts of southern West Bengal and parts of western Chhattisgarh: source and mobilization process. Curr Sci 2002, 82(6), 740-4.

Arsenic contamination problem in West Bengal and in Chhattisgarh is a natural phenomenon. The main sources of arsenic in the latter area are in weathered acid magmatic rocks of the Dongargarh rift belt and not from locally present sulphides. In West Bengal, arsenic-sorbed in Fe-oxyhydroxide was preferentially captured in argillaceous, organic-rich, mid-Holocene deltaic sediments. Arsenic concentrations are neither high nor very different between adjacently located polluted or unpolluted aquifers. Arsenic is released to groundwater in both cases by bio-mediated reductive dissolution of Fe-oxyhydroxide. In West Bengal, continued and increased recharging of shallow aquifer because of extensive pumping triggered the reduction process, by inducing and enhancing movement of groundwater having highly reducing degraded organic products.

6 illus, 39 ref

016950   Abbi S D S;Gosain A K;Narayanan P (NO, Meteorological Office, New Delhi) : Application of deterministic conceptual model for water balance studies. Mausam 2001, 1(1), 155-64.

Attempt has been made to study the water balance of Dandavathy a tributory of Tungabadhara river basin in Karnataka by the application of Sacramento model which is a deterministic conceptual model. Precipitation and the evaporation data have been used to allocate the moisture in various layers of the soil and the resultant runoff compared with the actual runoff for the prupose of the calibration of the model. The model is then used to study the water balance by the well known hydrological equation and results are found to be very encouraging.

2 illus, 9 tables, 2 ref

015986   Ubale M B;Farooqui M;Arif P M;Zaheer A;Dhule D G (Department of Chemistry, Aurangabad College for Women, Navkhanda Jubilee Park, Aurangabad-431 001) : Regression analysis of ground water quality data of old Aurangabad city (Maharashtra). Asian J Chem 2001, 13(4), 1667-9.

Ground water samples from different places of old Aurangabad city (Maharashtra) have been analyzed for various water quality constituents during 1998 and correlation coefficients among different parameters determined. A regression equation to predict the concentration of the water quality constituents having significant correlation coefficients with oxidation-reduction potential (ORP) and the usefulness of their equations in predicting the ground water quality have been discussed.

^ssc 3 tables, 6 ref

015985   Sultan S A R;Elghribi N M (Department of Marine Science, Faculty of Science, University of Qatar, P.O. Box 2713, Doha, Qatar) : Heat budget of the southeastern part of the Arabian Gulf. Indian J Mar Sci 2002, 31(1), 59-61.

Surface heat fluxes through the air-sea interface for the coastal water of the southeastern part of the Arabian Gulf have been estimated using the bulk formulas. The annual mean values of the sensible, latent and back ratiation fluxes are 3, 153 and 57 W/m² respectively. The annual mean of recorded solar radiation is 201 W/m², thus, giving an annual heat deficit of 6 W/m².

^ssc2 illus, 9 ref

015984   Sharma K D (Central Arid Zone Research Institute, , Jodhpur-342 003) : Water resource development in Jamnagar district, Gujarat, India. Ann Arid Zone 2000, 39(2), 145-50.

Regression models for rainfall-runoff-drainage basin area relationship, based on past 30 years, observtions, have been developed for Jamnagar district in arid Gujarat, India. The runoff coefficient varies from 0.07 to 0.29 and the runoff efficincy decreases with the increasing area of drainage basin, since large the basin, longer the flow paths and longer the opportunity time for rainwater infiltration. The probability of a severe drought by 2020 varies from 19 to 35% in various talukas in the district. The risk of failure of water control structures by a storm having 100 years as a return period is 63%. The study is useful in predicting the peak flows, water yield, rainwater infiltration, sediment transport and channel stability in the arid regions.

2 illus, 2 tables, 6 ref

015983   Rajshekhar C;Reddy P P (Geology and Paleontology Group, Agharkar Research Institute, G.G. Agarkar Road, Pune-411 004) : Ecology of beach rock fauna of the south Andaman Island, Bay of Bengal. Curr Sci 2002, 82(7), 881-5.

Late Holocene microfauna from the beach-rock of the south Andaman Island has been investigated. The beach-rock fauna reflects the reefal environment of deposition. The occurrence of raised beaches and terraces has been attributed to the neotectonic activity in recent times. C-14 dates indicate that the Wandoor beach-rock is younger (1540-1350 years B.P.) than the Chidyatapu beach rock (4410-3900 years B.P.) indicating at least two phases of neotectonic activity.

^ssc5 illus, 30 ref

015982   Mukhopadhyay S;Pandey Y;Dharmaraju R;Chauhan P K S;Singh P;Dev A (Department of Earth Sciences, Indian Institute of Technology, Roorkee) : Seismic microzonation of Delhi for ground-shaking site effects. Curr Sci 2002, 82(7), 877-81.

Microtremor measurements have been carried out in Delhi with an ultimate aim of seismic hazard microzonation for ground shaking site effects. The parameters required are resonance frequency and amplification of ground motion at that frequency. Resonance frequencies and lower bound estimates of the level of amplification of the horizontal motion with respect to the vertical motion (H/V) at various sites in and ground Delhi were estimated. The data shows variation in these parameters from one area to another. This could be due to variations in soil thickness and/or variations in the soil type. Our preliminary investigation shows that amplification of ground motion is very low on the ridge compared to that at soft-soil sites. The resonance frequency is high at sites close to the ridge and also to its west, compared to that at sites close to river Yamuna. Amplification of ground motion is more at sites close to the river compared to that the other sites investigated so far. As more data of this type become available, microzonation of Delhi would become possible.

^ssc4 illus, 1 table, 11 ref

015981   Lokesh K N;Narayana Shenoy K (NO, Karnataka Regional Engineering College, Surathkal-574 157) : Groundwater quality assessment in Udupi taluk, Karnataka. J Instn Publ Hlth Engrs India 1999, 4(Oct-Dec), 5-11.

Hydrogeochemical studies were carried out in Udupi taluk to assess the groundwater quality. Groundwater samples from 46 public borewells in Udupi taluk were collected both in pre-monsoon and post-monsoon seasons during the year 1996 and were chemically analysed. It is found from analysis that, in general, most of the chemical constituents are within the maximum permissible limits of W.H.O. Standards for Drinking Water and Indian Drinking Water Standards. However, some of the samples show pH less than 6.5. The analysis also reveals less concentration of fluoride than the desirable limit (<60>0.6 mg/L). Problems like high hardness and excess iron (<62>1.0 mg/L) are also observed. Though there is not much seasonal variation in TDS, increase in concentration of EC, Ca, HCO3 and Fe has been observed during post-monsoon period. Another problem experienced by the people of the area is the foul smell emitted by borewell water. All these problems are discussed in detail and some suggestions are made for better water management practices.

2 illus, 2 tables, 8 ref

015980   Anilkumar N;Dineshkumar P K (NO, National Institute of Oceanography, Regional Centre, P.B. No. 1616, Cochin-682 014) : Seasonal dynamics of Beypore estuary, Kerala coast. Indian J Mar Sci 2002, 31(1), 52-8.

Mixing characteristics of the Beypore estuary were determined up to 15 km upstream of Chaliyar river. The study area was divided into four sections (5 km interval) with two transverse stations on either side of each section. The diffusivity values were found to be almost equal in four sections during premonsoon months. In July it was 9.08 m²/sec at river mouth and zero at the upper reaches of the estuary. In postmonsoon season the diffusivity values decreased upstream. Maximum value of flushing time was computed in March (14.85 tidal cycle) and minimum in July (0.23 tidal cycle). At the river mouth the water flux was directed seaward during the postmonsoon and monsoon season. During the premonsoon period the transport was upstream and the net transport was higher during May. Maximum flux of the suspended sediment was obtained during July (1220.97 mg/cm²/sec) at the river mouth. Highly negative fluxes were obtained during premonsoon period with the highest negative value occurring during May (-381.31 mg/cm²/sec) at river mouth. During the study period the annual sediment input and the net sediment transported towards the sea were estimated to be 8.8 x 10⁴ tons/yr. The logarithmic values of Richardsons number (logRL) showed large variation at river mouth section of the estuary and at about 10 kms upstream during the postmonsoon period....

5 illus, 1 table, 14 ref

015154   Srinivasa Gowd S;Sudheer A S;Srinivasulu S (Department of Geology, Sri Venkateswara University, Tirupati-517 502) : Estimation of groundwater balance in the Peddavanka watershed, Anantapur district, Andhra Pradesh. J appl Hydrol 2000, 13(3-4), 36-43.

Attempt has been made to estimate the groundwater balance in the Peddavanka watershed, Anantapur District, Andhra Pradesh. The annual groundwater recharge is measured from the average annual rainfall, recharge through surface water bodies and recharge through applied irrigation. The annual groundwater drft is estimated based on the number of wells present in the watershed and the extent of area irrigated. The draft based on the crop extent under different crops is also taken into consideration for both kharif and Rabi seasons. From the study it is estimated that the annual groundwater recharge of Peddavanka watershed is 1995 ha.m. and the draft is estimated as 1615 ha.m. The annual groundwater balance of the Peddavanka watershed accounts for 380 ha.m which cannot be extracted due to the specific retention capacity of the soils present in the watershed.

3 illus, 1 table, 4 ref

015153   Shetty A V (NO, National Institute of Hydrology, Hard Rock Regional Centre, Belgaum-590 001) : Simulation of a coastal aquifer with a simple technique. J appl Hydrol 2000, 13(3-4), 1-13.

Change in ground water storage in an aquifer is reflected by the change in groundwater level. The trend in groundwater level fluctuations over the period is carried out and observed that negligible decrease in the water table. The relationship between monthly rainfall and monthly water table has been analysed for the impact of rainfall on aquifer system. It is also analysed for the storage or residence time of water table with respect to the recharge condition. The faster rate of recharge and discharge of water table indicated by the study. The effort has been made to simulate water table of Sithanadi basin by using a simple regression technique with weightage for the basin mean rainfall and the rainfall of a observation well for the defined period for the month of July, October, and May with an accuracy. The statistical test have been carried out to find out the suitability of the model.

9 illus, 2 tables, 5 ref

015152   Sentupta P R;Basak P (Department of Mathematics, University of Kalyani, Kalyani-741 235) : Variability of Indian monsoon rainfall. Proc Natn Acad Sci India-Sect A 1999, 69(2), 119-35.

Study of variability of southwest monsoon (SWM) rainfall is of considerable scientific importance. The complexities in understanding the behaviour of SWM rainfall are due to strong space-time variation involved in the phenomenon. Thus, for a meaningful study of variability, a comprehensive knowledge of spatial and temporal variability is essential. This requires identification of spatially homogenous regions and a subsequent study of its variability. Principal component analysis (PCA) has been applied to the SWM rainfall data of 200 stations to identify four broad principal regions connected to first six principal components. Subsequently, a hierarchical method of refining the homogeneous principal regions is found leads to 10 sequentially homogeneous regions. lastly, a statistical study of the area weighted rainfall and the significant principal compnents of the regions is presented. A significant interannual variability signal is found to exist in a particular region, namely the Himalayan foothills.

6 illus, 3 tables, 20 ref

015151   Rajan Babu A;Gupta R N (National Institute of Rock Mechanics, , Kolar Gold Field-563 117) : Classification of granite quarries - a base for technology management. J Mines Metals Fuels 2001, 49(8-9), 322-4.

In the area of globalization, privatization and liberalization, there is tough competition and no industry can prosper unless it improves the efficiency, minimises the cost of materials produced and increases the quality. No wonders can be produced howsoever advanced or sophisticated the technology may be. It is the right choice of the machinery and the trained personnel who can bring about the changes in the efficiency, quality and profitability of operations. the quarrying for dimensional stones thus becomes critical for its infamous methods of working. A quarry classification system for granites is suggested along with the desired degree of mechanisation to help the industry to quickly readjust and compete in the world market.

1 table, 7 ref

015150   Patel R C;Thakur S K (Department of Earth Science, Kurukshetra University, Kurukshetra-136 119) : Hydro-geomorphological studies of the Markanda basin, Haryana (India). J appl Hydrol 2000, 13(3-4), 20-9.

Water is elixir of life, incremental water demands have resulted in progressive development of ground water resource. The area being fresh water zone is affected by over exploitation/draft. Hence, this area requires an intensive investigation to fulfil the water need. The study area confined in south part of ?Sirmour district of Himachal Pradesh and northern part of Haryana State. It lies between 30.0' - 30.4' North latitude and 76.30' - 77.23' East longitudes. It falls in Survey of India toposheet no 53B and 53F. Geomorphology and satellite imageries are used to have an idea about the configuration and water potential zone.

7 illus, 3 tables, 7 ref

015149   Panda N K;Paul A K;Krishnan S (Directorate for Exploration and Research, Department of Atomatic Energ, , Hyderabad-500 016) : Commercial potential of almandine garnet from beach placer of Kalingapatnam coast, east coast of India. J Mines Metals Fuels 2001, 49(8-9), 337-40.

Demand of garnet has increased manifold in recent years due to its multifaceted industrial use. Most of the identified resources of garnet in India are of beach placer origin. Beach placer garnet of Kalingapatnam coast is one among them. The garnets from this coast are angular to subangular, colourless to pink to deep brownish red in nature. Over 90% of the garnet ar confined to size range of +0.106 mm. Microprobe analysis of different size garnet fractions reveals that they are essentially almandine-pyrope (Alm60.92PYr33.46 - Alm85.32Pyr4.28) variey and ar homogenous in nature. Lower molecular propertions of other end members (grossular and spessartine components) and and practically absence of andradite and uvarovite has been noticed from the analysis. Seventy five percent of the total reserve is restricted to a depth of 1.50 to 3.50 m. Eastern Ghat group of rocks and their altered products form the provenance for these garnets. The grade and mineral chemistry of gamet are well suited for sand blasting, water jet cutting and coated abrasives apart from water filtration. The associated economic heavy minerals ar ilmenite, rutile, zircon, and sillimanite along with garnet have a direct bearing on the economic potential of these mineral bearing sands of beach and dune origin.

2 illus, 9 ref

015148   Narayana Shenoy K;Lokesh K N (Department of Civil Engineering, Manipal Institute of Technology, Manipal-576 119) : Electrical resistivity survey for groundwater exploration in Udipi municipal area. J appl Hydrol 2000, 13(3-4), 30-5.

Sixteen vertical electrical soundings were carried out in and around the Udipi municipal area by employing Schlumberger electrode configuration. Layer parameters show that there are three to five layered types of filed curves. Iso-resistivity contour maps are prepared for half current electrode spacing viz., AB/2=30 m., and AB/2=60m. to delineate the low resistivity zones. Depth to water level map is correlated with the iso-resistivity contour map. From the results of vertical electrical soundings, subsurface lithology and depth to hard rock groundwater potential zones in Udupi municipal area have been delineated.

5 illus, 2 tables, 2 ref

015147   Krishnaveni S;Meena K;Manivel M (NO, Shrimathi Indira Gandhi College, Trichy) : Prediction of tank storage and groundwater level for irrigation in tank command using pattern recognition. J appl Hydrol 2000, 13(3-4), 66-74.

Enumerates the usefulness and effectiveness of least square estimation technique in predicting the tank storage and groundwater levels in rain-fed tank system. Bivariate regression equation is developed for predicting tank storage from the input of rainfall. By utilising the same equation the tank storage was predicted for the known year and compared with measured data. By the same way six multiple regression equations were arrived at to calculate the groundwater level in the tank command area by using rainfall and tank storage as independent variables. Using Pattern Recognition the Nearest Neighbour Algorithm and the Hamming distance Method is selected used for Recognising the area of free catchment, intercepted catchment, and the command area.

4 illus, 2 tables, 5 ref

015146   Khichar M L;Ram Niwas;Som Pal (Department of Agricultural Meteorology, CCS Haryana Agricultural University, Hisar) : Markov chain model for use in analysis of south west monsoon rainfall of arid zone in Haryana. J appl Hydrol 2000, 13(3-4), 60-5.

Markov chain model has been fitted to weekly rainfall data of the monsoon season of Hisar station representing the arid zone of Haryana. The data used for this study was 41 years (1958-98) on weekly basis. the probabilities of different length and expected frequencies of dry spells have been calculated. The initial and conditions probabilities of dry and wet spell was analysed and its application to the management of agricultural operations in Kharif crop was also discussed.

1 illus, 2 tables, 8 ref