023213   Maitra M;Bose M K;Ray J (Geol Dep, Presidency College, 86/1 College Street, Kolkata-700 073, Email: monojmaitra@hotmail.com) : Interpretative mineral chemistry of ultramafic rocks of Chalk hills, Tamil Nadu. J Geol Soc India 2006, 68(5), 831-40.

The ultramafic rocks of Chalk Hills near Salem, comprise dunite, wehrlite and olivine clinopyroxenite in association with mafic alkaline rocks. The constituent phases of the ultramafics have been analyscd and their compositional data have been evaluated to assess petrogenetic factors. Dunite appears to be restite formed through mantic melting whereas wehrlite and olivine clinopyroxenite represent successive progressive cumulation products from transported high magnesian melt. Mineral chemistry of mafic phases and compositional interrelation between them indicates an equilibration temperature of 1022° to 1088°C for wehrlite and a relatively lower telI1perature level (ca. 900°C) for olivine clinopyroxenite. It appears that the extracted) high magnesian melt generating the wehrlite and olivine clinopyroxenite cumulates. equilibrated at shallower level, near base of the crust under ca. II kb pressure.

5 illus, 6 tables, 38 ref

023212   Lal B;Singh O P;Prasad O (India Meteorological Dep, , New Delhi) : Value addition in district level dynamical forecast during intense rainfall spells over the west coast of India. Mausam 2006, 57(3), 411-18.

Occurrences of intense rainfall events over west coast of India during monsoon are intimately linked to the core of maximum winds over the Arabian Sea. ECMWF (Europian Centre for Medium Range Weather Forecasting) predicted 72 hr flow pattern at 850 hPa has been used to develop a quantitative method for value addition in the district level dynamical forecast system for intense rainfall over the west coast. It has been found that the amount of rainfall over the west coast is significantly correlated to 72 hr ECMWF forecast of maximum wind speed over the Arabian Sea along the west coast. The latitudinal width of the heavy rainfall belt over the west coast has got significant correlation with the location of maximum wind core along the west coast. It has been shown that the strength and location of the 72 hr predicted core and fetch of maximum winds could be used as potential predictors in the value addition for 72 hr heavy rainfall forecast along the west coast of India during summer monsoon.

3 tables, 2 illus, 8 ref

023211   Kalsi S R;Jenamani R K;Hatwar H R (India Meteorological Dep, , New Delhi-110 003) : Meteorological features associated with Indian drought in 2002. Mausam 2006, 57(3), 459-74.

India experienced severe drought in the year 2002 after 14 consecutive years of good monsoon. On the monthly time scale, July had the worst rainfall in the recorded history of monsoon dating back to middle of nineteenth century when the country as a whole registered rainfall deficiency of 51.5%. Another notable feature was that for the first time in the last 133 years, not a single depression or cyclonic storm formed during the whole southwest monsoon season. The advance of monsoon over India was accompanied with frequent as well as prolonged stagnations. The monsoon failed to arrive for the first time in extreme northwest India during the first half of the season since 1960. In the study, various features of monsoon such as onset, progress, stagnation, different synoptic and semipermanent features and characteristics of rainfall of southwest monsoon in 2002 over India have been discussed. A comparison of these features with those in the earlier drought years has been made. Large-scale mean monthly anomalous ocean and atmospheric conditions over Indo-Pacific region have also been investigated to find out the possible causes for drastic failure of the monsoon during July 2002. Results show that many abnormal and unique features during 2002 have resulted into all India drought. Study also shows that absence of favourable regional intra-seasonal features like monsoon disturbances and semi-permanent systems, presence of very weak low level jet, penetration of strong mid-latitude westerlies, weak to moderate El-Nino with most intense warming over Nino 4 region of Pacific Ocean during monsoon months together with higher frequency of typhoon formation over the region are the main causes that led to one of the highly pronounced rainfall deficiencies in the month of July.

4 tables, 4 illus, 25 ref

023210   Kalita K D;Gogoi B (Applied Geology Dep, Dibrugarh Univ, Assam-786 004, Email: kalpana_d_kalital@redifmail.com) : First report of coralline red algae in the late palaeocene Lakadong limestones of Mawsynram area, Meghalaya. J Geol Soc India 2006, 68(5), 779-83.

Reports for the first time nine species belonging to eight genera of coralline red algae from the Late Palaeocene Lakadong Limestone Member of Sylhet Limestone Formation of Mawsynram area of Meghalaya in Northeastern India. The reported species are Mesophyllum meghalayensis, lithoporella melobesioides, Jania occidentalis, Distichoplax biserialis, Disrichoplax raoi, Dissocladella lakadongensis, Archaeolithothamnium sp., Corallina grandis, Amphiroa sp.

3 illus, 1 table, 19 ref

023209   Jayappa K S;Vijaya Kumar G T (Marine Geol Dep, Mangalore Univ, Mangalagangotri-574 199, Email: ksjayappa@yahoo.com ) : Beach morphological studies in India. J Geol Soc India 2006, 68(5), 874-84.

This review is based on a comprehensive search of literature on beach morphological and nearshore dynamics studies in India. It includes importance of beach morphological studies, critical evaluation of various methods approaches and tools used, sediment dynamics and causes for coastal erosion. coastal protection structures and their impact on beach morphology and shoreline changes. The objectives of this paper are to: (I) review the state-of-the-art of research conducted and inferences drawn in the country on beach morphology, (2) understand the impact of coastal structures (seawalls and Qreakwaters) on beach morphology and shoreline changes, and (3) to identify the grey areas in beach morphological studies and suggest the approaches for future research or field monitoring programs.

1 illus, 100 ref

023208   Jaiswal K;Sinha R (Civil Engineering Dep, Indian Institute of Technology, Bombay Powai, Mumbai-400 076) : Probabilistic modeling of earthquake hazard in stable continental shield of the Indian peninsula. ISET J Earthquake Technol 2006, 43(3), 49 64.

Presents the probabilistic assessment of seismic hazard associated with the stable continental shield of peninsular India (10°N-26°N; 68°E-90°E) in terms of peak ground accelerations for different levels of ground shaking. Discusses the procedure for evaluating the probabilistic seismic hazard using a knowledge-tree approach. Attenuation relationships proposed for peninsular India and those proposed for the other stable continental regions such as Central and Eastern United States have been used in this study. The results show that for many parts of peninsular India, the estimated seismic hazard is higher than the level specified in the current seismic zoning map given in IS 1893-2002.

7 illus, 1 table, 31 ref

023207   Hire P S;Kale V S (Geography Dep, Univ of Pune, Pune-411 007) : Geomorphic effectiveness of high-magnitude floods on the Tapi river: evaluation based on flood hydrographys and stream-power graphs. Trans Inst Indian Geogr 2006, 28(2), 175-82.

An attempt has been made to quantitatively evaluate the geomorphic effectiveness of three large-magnitude floods that occurred in 1959, 1968 and 1969 in the lower Tapi Basin. Flood hydrographs available for these and other flood events show that the duration of floods can range from 6 to 10 days, and in exceptional cases up to 15 days. Geomorphologically, the channel response to such long-duration floods is likely to be significant especially in alluvial reaches in terms of bed and bank erosion as well as coarse sediment transport. The temporal variations in specific stream energy over the flood period were evaluªated for these three flood events by constructing stream-power graphs. The flood hydrograph, the channel slope and the hydraulic geometry equations were used to compute the unit stream power and to construct the stream-power graphs. The graphs derived for two great and one common floods indicate that the power per unit area during such fluvial events is sufficiently high for several tens of hours to produce substantial changes in the alluvial sections of the Tapi River.

3 illus, 16 ref

023206   Gupta R C;Das M (Meteorological Centre, , Gangtok, Sikkim) : Recent trends in temperature (cold wave condition) and rainfall over Gangtok city. Mausam 2006, 57(3), 507-12.

1 table, 3 illus, 14 ref

023205   Gore P G;Joshi P R;Dikshit S K (India Meteorological Dep, , Pune) : Disastrous weather events of extreme heavy rainfall in West Bengal. Mausam 2006, 57(3), 513-17.

4 tables, 2 illus, 10 ref

023204   Golani P R;Dora M L;Bandyopadhyay B K (Geological Survey of India, Project Thematic Mapping, , Op. Maharashtra, Seminary Hills, Nagpur-440 006, Email: amsejpr@rediffmail.com ) : Base metal mineralisation associated with hydrothermal alteration in felsic volcanic rocks in proterozoic betul belt at Bhuyari, Chhindwara District, Madhya Pradesh. J Geol Soc India 2006, 68(5), 797-808.

The southeastern part of the Proterozoic Betul Belt exposes a felsic-dominated sequence around Bhuyari in the Kanhan river sector. The felsic volcanic rocks, identified as rhyolite occur in the form of two mappable bands in a milieu of biotite ± hornblende bearing quartzo-feldspathic rocks of sub volcanic affinity. A very well developed zone of hydrothermal alteration is recognized in rhyolite that occurs to the immediate south of Bhuyari village. The hydrothermal facies mapped in the alteration zone include sericite - muscovite-bearing rhyolite, phlogopite ± spessartite biotite schist and tremolite (± actinolite) - rich rock with serpentine, talc, epidote and dolomitic carbonates. Discrete grains of fluorite and REE bearing flourcarbonates form part of the hydrothermal mineral assemblage. Apart from the magnesian enrichment, the occurrence of spessartite garnet, epidote and sporadic development of staurolite indicate significant fluxes of manganese, calcium and alumina in the zone of hydrothermal alteration. The alteration is attendant with polymetallic base metal mineralisation which is invariably zinc-dominated. Bedrock samples and selected channel sampling indicate that the tremolite-rich facies is intensely mineralized, followed by phlogopite ± garnet biotite schist. Primary sulphides observed in a dug well section are pyrite, sphalerite, galena and chalcopyrite which occur as disseminations and also as several millimeter thick semiconformable veins. Rare quartz phenocryst-groundmass relationship in the mineralized host rock from the dug well provide incontrovertible evidence for the volcanic affinity of the base metal mineralisation.

16 illus, 5 tables, 19 ref

023203   Fareeduddin (Geological Survey of India, , AMSE Wing, Vasudha Bhavan, K.S. Layout, Bangalore-560 078, Email: Fareedromani@hotmail.com) : Chondritic features in a diamondiferous rock, Majhgawan, central India: implications for diamond genesis. J Geol Soc India 2006, 68(5), 743-60.

Majhgawan, on the southeastern margin of the arc shaped Bundelkhand craton and within the Mesoproterozoic Vindhyan basin in Central India hosts the only diamond producing mine in India. Variously classified as ullramafite, agg!omeralic luff, kimberlite, lamproile, orangeile, serpentine rock, a transitional rock etc., the host rock for diamond, comprising mainly ultramafic hreccia, and exposed in an elliptical outcrop pattern, shows significant differences in bulk chemistry and mineral compositions with other known kimberlites and related rocks of India. It shows textural features suggestive of crater facies volcanic eruption. Several distinctive and hitherto unreported features of shock metamorphism in olivine such as parallel fractures, planar deformational features (PDFs), shock mosaicism, arrested mineral melts, veinlets of rock melts, mixed melts, spherules and darkened silicates have been documented, recording up to S6 stage of shock metamorphism and shock pressures <62> 45 Gpa. These shock metamorphic imprints as well as the presence of variety of features bearing startling resemblance to the chondrules suggest that the Majhgawan ultramafic breccia contains traces of chondri tic components in it. Though it is interpreted here that the Majhgawan body is a result of a billion year old, impact triggered eruption of mantle material, which has incorporated the surface remains of the chondri tic matter, clearly, much more study is called foron these lines to understand the textural and mineralogical complexities exhibited by the Majhgawan rocks. It is argued that the difficulty in providing a descriptive classification for this rock within the framework of the IUGS schemes for terrestrial rocks is attributed mainly to its identification as simple rock akin to the known diamondiferous primary sources. Some new thoughts on the genesis of the diamonds in the light of these findings are also touched upon.

4 illus, 6 tables, 41 ref

023202   Dikshit J K (NO, , 3, Salil Apts, Sanewadi-Aundh, Pune-411 007) : Hurricane katrina - observations on a cyclone that devastated new orleans and the Mississippi coast in 2005. Trans Inst Indian Geogr 2006, 28(2), 157-74.

Devastating New Orleans and the Mississippi coast in August 2005, Hurricane katrina became the object of diversified analysis and research of a number of disciplines. Looks at the vulnerability of New Orleans and the Mississippi delta to cyclonic threats. It tries to bring out some of the factors that contributed to strengthening the hurricane over the Gulf of Mexico. However, adverse meteorological conditions alone are not enough to explain the scale of the disaster. The deterioration of the deltaic environment, the loss of wetlands, and the overemphasis of and dependency on technology versus nature in reclaiming swamps and expanding settlements beyond otherwise viable limits are some of the causal factors. Further discusses some special social aspects of New Orleans and problems of the disaster prevention and management.

7 illus, 26 ref

023201   Chaudhuri S (NO, Calcutta Univ, Kolkata) : Ampliative reasoning to view the prevalence of severe thunderstorms. Mausam 2006, 57(3), 523-6.

1 table, 1 illus, 12 ref

023200   Chattopadhyay S;Saji Kumar S;Chattopadhyay M (Centre for Earth Science Studies, , Trivandrum-695 031, Email: radresource@vsnl.com) : Landscape evolution in parts of Vamanapuram drainage basin, Kerala - a hypsometric approach. J Geol Soc India 2006, 68(5), 841-56.

Morphometric and hypsometric parameters provide significant indicators for deciphering the erosional processes, and influence of geologic and tectonic factors on landscape development. The study covers 22 fourth order sub-basins of the Vamanapuram drainage basin of Kerala. Based on hypsometric analysis the sub-basins are grouped into three sets representing old, mature and late mature stage. It is possible to identify two erosional processes. namely, fluvial and diffusive, from hypsometry of the sub-basins. Diffusive processes dominate sub-basins adjoining the Western Ghats, particularly those draining the flank of the Ghats, while fluvial processes dominate the sub-basins in the midlands and foothills. However there are some sub-basins in the midland where diffusive processes are found to be active. Relative uplift of the sub-basins indicates fault-related movement, and possible reactivisation of old fault lines or lineaments.

16 illus, 2 tables, 22 ref

023199   Chakraborty T K (Regional Meteorological Centre, , Kolkata-700 027) : Prediction of winter minimum temperature of Kolkata using statistical model. Mausam 2006, 57(3), 451-8.

Five parameter multiple linear regression model for objective forecasting of minimum temperature of Kolkata (Alipore) with 12 hours lead period has been developed. The predictors are chosen from the available surface data of Alipore observatory and low level wind data of M. O. Kolkata. Model has been developed from data sample comprising of 237 days (in January and February, period: 1997 - 2000) after stationary test of minimum temperature data of much longer period (1988-2004). The model is tested with independent sample of 178 days. Efficiencies of the model have been tested with statistical skill score and found to be positive. The model can be used by the forecaster for assessing prediction minimum temperature and modify if cloud cover and wind flow pattern are expected to change subsequently.

6 tables, 4 illus, 10 ref

023198   Chakraborty P K;Srivastava K (NO, , Meteorological Office, N.S.C.B.I. Airport, Kolkata-700 052) : Pre-monsoon maximum temperatures over New Delhi, Mumbai & Chennai and possible solar influence. Mausam 2006, 57(3), 437-44.

The general variations of pre-monsoon maximum temperature over New Delhi, Mumbai and Chennai for the 51 years period from 1951 to 2001 and its possible association with solar activity [estimated in terms of annual mean sunspot (SS) numbers] have been analysed statistically. The temperature series indicate an approximate periodicity of 3 years for all the stations with an increasing trend for Chennai only. Analysis of the variations with respect to solar phases (using a growth rate model) indicates an increasing trend of temperature in 73% cases during solar minimum to maximum phases. The correlation coefficient between pre-monsoon temperature and annual mean SS nos. of the preceding year indicate a positive association when the latter exceeds some critical value approximately 140 and it (+0.647) is significant for New Delhi. The present result is consistent with similar studies for stations over eastern India.

2 tables, 3 illus, 23 ref

023197   Calvi G M;Pinho R;Magenes G;Bommer J J; Restrepo-Velez L F;Crowley H (Structural Mechanics Dep, Univ of Pavia, Pavia, Italy) : Development of seismic vulnerability assessment metodologies over the past 30 years. ISET J Earthquake Technol 2006, 43(3), 75-104.

Models capable of estimating losses in future earthquakes are of fundamental importance for emergency planners and for the insurance and reinsurance industries. One of the main ingredients in a loss model is an accurate, transparent and conceptually sound algorithm to assess the seismic vulnerability of the building stock and indeed many tools and methodologies have been proposed over the past 30 years for this purpose. Takes a look at some of the most significant contributions in the field of vulnerability assessment and identifies the key advantages and disadvantages of these procedures in order to distinguish the main characteristics of an ideal methodology.

20 illus, 2 tables, 92 ref

023196   Bisht B S (Atomic Minerals Directorate for Exploration and Research , Atomic Ener, , Begumpet, Hyderabad-500 016, Email: dr_bisht@rediffmail.com) : Compositional characterisation of biotite from the Gamkak and Jaivor areas in the West Siang district, Arunachal Pradesh with implications on Uranium mineralisation. J Geol Soc India 2006, 68(5), 784-8.

Compositional characterisation of biotite from two distinctly different geological domains of the Gamkak and Jaiyor areas in the West Siang district, Arunachal Pradesh has been carried out. The environments of formation of biotite in the areas have been inferred from the compositional data. Conspicuous differences in chemistry have been observed in biotite from metamorphic mica schist and hydrothermal uraniferous vein. Compositionally, vein biotite associated with uranium minerals, uraninite, brannerite and occasionally davidite, contain significantly higher (mean) MgO (17.38%), F (7.33%) and SiO₂ (38.95%) and lower (mean) Al₂O₃ (12.78%) when compared to the biotite in non-uraniferous mica schist (mean) MgO (5.67%), F (1.53%). SiO₃ (34.54%) and Al₂O₃ (17.58%). Minor differences do exist in the concentration of TiO₂, FeO^t and Na₂O in these biotites. The MgO-FeO^t- Al₂O₃ plot reveals that the biotite from uraniferous vein is of calc-alkaline variety and that in mica schist is peraluminous.

2 illus, 1 table, 12 ref

023195   Bhu H;Sharma B L (Geol Dep, Mohanlal Sukhadia Univ, Udaipur-313 002, Email: harsh_bhu2003@yahoo.com) : Dynamic recrystallisation and quartz fabric in palaeoproterozoic conglomerate, East of Udaipur, Rajasthan. J Geol Soc India 2006, 68(5), 819-30.

Reports the study of strain analysis on pebbles of a horizon of polymictic conglomerate belonging to the Debari Formation of the Aravalli Supergroup. The variable shape geometry of pebbles observed in different parts of the conglomerate outcrops, which cover a long linear distance east of Udaipur, is indicative of heterogeneous superimposed strain on somewhat non-spherical initial bodies. Microtextural studies indicated a variety of strain forms in constituent grains of both pebble and matrix along with attendant recovery through sub-grain formation and recrystallisation. Mica grains in the matrix have acted as a strain-partitioning mineral. The lattice preferred orientation of c-axes in quartz is comparable to partially developed Type I pattern developed in regions of coaxial deformation. The pattern has been influenced by strain and dynamic recrystallisation. The slip planes that operated in the deformation of quartz grains varied from basal slips to prism slips. Basal slips were dominant at low temperature and low strain regions in quartz while prism slips at moderately higher temperature and moderate strain. The variation in slip planes can be accounted by inhomogeneous nature of deformation possibly due to difference in critically resolved shear stresses in the conglomerate.

9 illus, 2 tables, 50 ref

023194   Adarsh Kumar;Qureshi T A;Parashar A;Patiyal R S (Applied Aquaculture Dep, Barkatullah Univ, Bhopal-26) : Seasonal variationin physico-chemical characteristics of Ranjit Sagar reservoir, Jammu & Kashmir. J Ecophysiol occup Hlth 2006, 6(3-4), 159-63.

The present study deals with the assessment of physico-chemical characteristics of Ranjit Sagar reservoir, Jammu. The physico-chemical characteristics of Ranjit Sagar reservoir were studied and analyzed for a period of one year, during January 2004 - December 04. Seasonal variations from four sampling stations of the reservoir were observed. Various parameters including temperature, conductivity, transparency, pH, dissolved oxygen, CO₂, total alkalinity, chloride, phosphate, nitrate, calcium and total hardness were analyzed. The results revealed that there were significant seasonal variations in some physico-chemical parameters and most of the parameters were in the normal range and indicated better water quality of reservoir.

1 table, 23 ref

022211   Yagoub M M;Reddy Kolan G (Geography Program, Humanities and Social Sciences College, United Arab Emirates Univ, P.O. Box-177 71, Al-Ain, UAE) : Monitoring coastal zone land use and land cover changes of Abu Dhabi using remote sensing. J Indian Soc Remote Sens 2006, 34(1), 50-88.

Coastal zones are most vulnerable for landuse changes in this rapid industrialization and urbanization epoch. It is necessary to evaluate land use - land cover (LULC) changes to develop efficient management strategies. The main objective of this paper is to evaluate and quantify Abu Dhabi coastal zone LULC changes from 1972 to 2000 using multi-temporal LANDSAT satellite data and digital change detection techniques. Supervised classification coupled with expert visual interpretation techniques were used to produce LULC classified images with an accuracy of 88%. Change detection process was achieved by applying post-classification comparison techniques in ENVI software. From this study it has been observed that the important coastal landuse types of Abu Dhabi coast .i.e. wetlands and woody Vegetation (Mangrove, represented by a single species, Avicennia marina) have been reduced drastically in their extent due to reclamation, dredging, tipping and other anthropogenic activities along the coastal zone. However, it has been observed that there is rapid increase in the man-made plantation and managed vegetation from 1990 to 2000 due to the Abu Dhabi government initiation. This study has given good insight into Abu Dhabi coastal zone changes during last 3 decades.

ref

022210   Vasantha Rao B V T (College of Engineering, Kakatiya Univ, Kothagudem, Khammam Dist-507 101) : Beach characteristics at suryalanka area, east coast of india. J Indian Acad Geosci 2006, 49(1), 27-31.

Features of erosion and deposition are characteristics of all dynamic beaches and recognition of such features on beaches forms an important aspect in the study of evolution of beaches. The beach dunes East of Suryalanka is a barrier beach developed on the seaward side of a sand barrier which has emerged East-West about 10 Kms., East of Suryalanka, Scarps of bigger as well as smaller magnitude are being developed, behind and across the backshore-zone respectively, due to the erosive action of high and low tidal waves. Beach cusps and beach stratification throw light on the differences in the wave approach and energy conditions operative at Suryalanka Bay. The sand dunes associated with the beach of this bay are identified as precipitation dunes.

6 illus, 12 ref

022209   Tlas M;Asfahani J (Atomic Energy Commission, , P O Box 6091, Damascus, Syria) : Interpreting self-potential anomalies caused by two-dimensional inclined sheet like-structure using maximization of a likelihood funtion. J Geophys 2006, 27(3), 27-35.

An interpretatation method based on the constrained, nonlinear mathematical optimization concept has been implemented in order to interpret self-potential (SP) anomaly due to a two-dimensional inclined sheet like-structure. The geophysical problem related to such a structure is mathematically formulated as a constrained, nonlinear optimization problem. This problem is thereafter transformed into an unconstrained, nonlinear optimization one by using an exponential penalty function. This unconstrained, nonlinear optimization problem can then be solved by Hooke and Jeeves direct search algorithm in order to estimate the geophysical parameters of the sheet-like structure, i.e., depth of the centre of the sheet z , inclination angle θ half length of the sheet a and electric dipole moment k . The proposed new interpretation method has been first tested on a theoretical example with different random noise. A very close agreement has been obtained between theoretical and computed parameters. The validity of this method is also tested on a practical field example, where the observed field data was previously analyzed by different geophysical interpretative methods. The agreement between the results obtained by the proposed technique and those obtained by other geophysical methods is good. A statistical analysis has also been carried out to demonstrate the accuracy and the efficacy of the proposed interpretation method.

2 tables, 2 illus, 17 ref

022208   Suresh R;Kundu S K;Bhatnagar A K;Bhatia R C (India Meteorological Dep, , Chennai-600 001) : On forecasting tracks of tropical disturbance using ATOVS data over Bay of Bengal. Mausam 2006, 57(4), 609-18.

Advanced TOVS (ATOVS), comprising the Advanced Microwave Sounding Unit (AMSU), data obtained from polar orbiting satellites NOAA 15 and 16 during the life cycle of a tropical depression and two tropical cyclonic storms during 2002-03 have been analysed to predict the track of these disturbances. The mid-tropospheric warming due to altostratus outflow from these weather disturbances in the layer 700 - 400 hPa which protrudes about 200 -700 km ahead the storm acts as a pre-cursor to predict the movement of the disturbances with a lead time of about 6 to 24 hours. The disturbance almost follows the axis connecting the centre with the warm tongue that protrudes ahead of the disturbance in the mid-troposphere. While warm core of 7 to 13° C is centered around the upper tropospheric level (250 - 200 hPa) in the case the two moderate intensity tropical cyclones, no significant warmness could be seen in the depression stage.

3 tables, 8 illus, 19 ref

022207   Sudhakar Reddy Y;Faris A A (Geology Dep, Osmania Univ, Baghdad, Iraq) : Geo-technical investigations along Godavari (Inchampalli) - krishna (Nagarjunasagar) link canal-Halia river cross drainage-a case study. J Indian Acad Geosci 2006, 49(1), 21-6.

Geotechnical studies were carried out at Halia river cross drainage (CD) by drilling five bore holes up to a maximum depth of 20 m. Geologically the area of geotechnical investigations along Halia river cross drainage is occupied by granodiorites, granites and gneisses with enclaves/xenoliths of amphibolites of peninsular gneissic complex of Pre-Cambrian/Achaean age. The geo-technical investigations includes collection of disturbed and core samples for analysis of various properties , determination of crushing strength of rock core samples, rock quality designation, standard penetration test and in situ permeability tests. The result show thick silty and sandy soil underlain by completely disintegrated rock followed by light gray and pink , medium to coarse grained granite traversed by vertical to sub vertical Joints/fractures . The evaluation of borehole geological data indicate that the depth to the foundation grade rock range between 15.5 and 16.7 m. below the ground level. Based on the nature of the strata available, it is suggested to carry out consolidation grouting at Halia, river cross drainage site of the pier foundation to improve the rock mass conditions.

2 tables, 2 illus, 5 ref

022206   Srinivas C V;Venkatesan R;Muralidharan N V; Das S;Das H;Eswara Kumar P (Radiological Safety Div, SE Group, Indira Gandhi Centre for Atomic Res, , Kalpakkam-603 102) : Operational mesoscale atmospheric dispersion prediction using a parallel computing cluster. J Earth Syst Sci 2006, 115(3), 315-32.

An operational atmospheric dispersion prediction system is implemented on a cluster supercomputer for Online Emergency Response at the Kalpakkam nuclear site. This numerical system constitutes a parallel version of a nested grid meso-scale meteorological model MM5 coupled to a random walk particle dispersion model FLEXPART. The system provides 48-hour forecast of the local weather and radioactive plume dispersion due to hypothetical airborne releases in a range of 100 km around the site. The parallel code was implemented on different cluster configurations like distributed and shared memory systems. A 16-node dual Xeon distributed memory gigabit ether-net cluster has been found sufficient for operational applications. The runtime of a triple nested domain MM5 is about 4 h for a 24 h forecast. The system had been operated continuously for a few months and results were ported on the IMSc home page. Initial land periodic boundary condition data for MM5 are provided by NCMRWF, New Delhi. An alternative source is found to be NCEP, USA. These two sources provide the input data to the operational models at different spatial and temporal resolutions using different assimilation methods. A comparative study on the results of forecast is presented using these two data sources for present operational use. Improvement is noticed in rainfall forecasts that used NCEP data, probably because of its high spatial and temporal resolution.

6 tables, 14 illus, 16 ref

022205   Sridharan M;Gururajan N (IIG Magnetic Observatory, , ) : Fractal behavior of geomagnetic storm on 29-31 october 2003. Int J mathl Sci 2006, 5(2), 303-11.

`Fracal Dimension' can be best studied to understand the complexity of a dynamical system. Fractal geometry allows the description of natural patterns by simple numbers to facilitate their comparison and to establish and test models of formation. The purpose of this paper is to quantify the intensity of the great geomagnetic storm in terms of `Fractal dimension'. the attracter associated with the storm diverging at the Polar Regions and converging at the lower and middle latitudes has been revealed in phase space reconstructions.

4 illus, 17 ref, 1 table

022204   Singh S R (National Bureau of Soil Survey and Land Use Planning, , Amravati Road, Nagpur-440 010, Email: srsingh@nbsslup.ernet.in) : Drainage morphological approach for water resources development of the Sur catchment, Vidarbha region. J Indian Soc Remote Sens 2006, 34(1), 79-88.

Drainage channels as represented over the topographical maps of the Survey of India on scale 1:50,000 and depicted over the IRS-IB imageries (May 1993) and limited photographs are characterized in view of its areal, linear and abstract properties associated with the Archean gneissic plate of the Sur catchment spread over 983 km². Morphological characteristics of the drainage lines as appear in shape, size, number and order, length, Dd, Sf, Rb, Is, II, Rc, It and infiltration number are derived to trace its usefulness for surface water development. Chiefly dendritic, sub-dendritic and sub-parallel drainage patterns evolved out of the dissected hills, undulating plateau, pediplain and the gently sloping plain persisting under dry sub-humid climatic conditions at an elevation ranging from 246 to 580 m above MSL have given rise to situations suitable for good bunding sites mostly occurring at 3rd and 4th orders of streams for water resource development. Detailed analysis of dominant V order segments (Total 7) suggests high intensity of flood occurrence at a time at the outlet point of the streams indicated along the increased values of Dd, Sf, Rb and Rc thereby cautioning proper bunding structure at sites marked on the map for irrigation of crops beyond rainy season.

3 tables, 4 illus, 9 ref

022203   Shemang E M;Jacoby W R (Geology Dep, Botswana Univ, Gaborone, Botswana, Email: shemae@mopipi ub bw) : Interpretation of gravity anomalies over the gongola arm, upper benue trough, Nigeria. J Geophys 2006, 27(3), 37-46.

A regional gravity survey of the Gongola Arm of the Benue trough was carried out with the objective of determining structures of both local and regional interest. The results of the gravity interpretation showed that the area of study is characterised by negative Bouguer anomalies that trend in the NE-SW direction and range in values from-75 to -15 mGal with an average of-42 mGal. A first order polynomial was used to approximate the regional anomalies in the area. The residual gravity anomaly map shows anomalies that range in values from -32 to +20 mGal. 2-D modelling of the residual gravity anomalies suggests that the area has a horst and graben structure, with the grabens being as large as 60 km in width and filled with sediments that are up to 4.5 km thick. Results also suggest the existence of high-density rocks of basic composition at depth. The general indication of the structure of the Gongola arm of the Benue trough is that it is a half graben (width ca 60 km) bounded by normal faults.

1 table, 10 illus, 35 ref

022202   Sharma A A L N;Srinivas S (Meteorology & Oceanography Dep, , Visakhapatnam-530 003) : Anomalies in terrestrial hydrological cycle - India. Mausam 2006, 57(4), 639-52.

It is reported that the traced footprints across the world are the consequences of the perturbed world climate system that might be responsible in intensifying the world hydrological cycle with regional implications. An attempt is made to understand this fact in case of hydrological regime over India through water balance model. The investigation mainly addresses the climate teleconnection impacts of ENSO/LNSO signal on the hydrological fluxes for All India.

4 tables, 13 illus, 21 ref

022201   Sen S;Chatterjee M;Sen G K (School of Oceanographic Studies, Jadavpur Univ, Kolkata-700 032) : Mobile GIS for issuing warning for storm and natural hazard along the Digha coast. Envir Ecol 2006, 24(4), 820-6.

Coasts are susceptible to storms, storm surges, extreme wind impact during storm, wave induced erosion activity and coastal inundation that cause large amount of loss with respect to human life and property. During storm fishermen in the rough sea often fails to identify the right track to reach safely to the coast bypassing the impending storm. In this study attempts were made to assess the procedures for appropriate warning system against natural coastal hazards. The data obtained from India Meteorological Department, and the satellite imagery of cloud cover available were used to provide necessary information about the growth of cloud development, cloud cover, association with storm, storm position at various pressure levels. The rate of movement of the system and the direction along which the clouds moved away were computed. These real time satellite images of cloud, real time observation of meteorological parameters, available output of different global prediction models, real time observation of rising water level of tide records and using position of water level in open coast were used to provided real time now cast of changing water level, wind pattern pressure variation from time to time and movement of cloud cover helped in setting an appropriate warning message so that necessary action could be undertaken to evacuate people from the area under storm impact threat.

12 illus, 6 ref

022200   Saxena P R;Reddy U V B;Divakara Rao V (Applied Geochemistry Dep, Osamania Univ, Hyderabad) : Trace element distribution in the granite in the eastern margin of Cuddapah basin Andhra Pradesh - genetic significance. J Indian Acad Geosci 2006, 49(1), 7-10.

Proterozoic granites occur along the eastern margin of Cuddapah basin at Kanigiri, Darsi, Vinukonda, Marripudi and Ramavaram as bosses and are syn-to post tectonic in nature. Th, U, Rb and Sr in these granites show random variation and majority of these granites show Th-enrichment. Overall chemical composition and REE distribution patterns suggest well fractionated A-type nature of these granites. Ba depletion and low Sr values, enrichment of Th and Rb suggest that these are syntectonic within plate granites and Th appear to have been mobilized from the Eastern Ghat granulite belt that itself is Th rich province.

1 table, 3 illus, 12 ref

022199   Sarkar J;Gadgil A S;Mukherjee A K;Soni V K (Air Pollution Unit, India Meteorological Dep, , Pune) : Analyzing rainwater chemistry at the continental GAW station Nagpur. Mausam 2006, 57(4), 653-62.

Rain water chemistry of Nagpur for the period 1981-1996, has been studied. The analysis reveals that at Nagpur rain water there is less marine influence on the concentrations of Na⁺ and Cl. Pre-monsoon months, as well as the season as a whole, record higher NO₃ concentration which could be attributed to frequent thunderstorm activities in this season. During monsoon months, concentration of all the constituents of rainwater, except K⁺, goes on decreasing till August. However, in September increase in concentration is observed for all the constituents. Deposition values of Cl^- and Na⁺ are found to be quite low in comparison to that at coastal stations. SO₄^-2 deposition value is comparable to the values reported in some parts of USSR. Study of ratios between various constituents and a comparison with sea water ratios reveals that rainwater at Nagpur gets enriched in terms of Na⁺ from other sources besides sea water. pH values exhibited large variation. In monsoon, June onwards pH goes on decreasing and lowest value is obtained in September. This could be attributed to the preferential removal of basic cations by rainwater. In the peak summer of April and May higher values of pH could be attributed to the abundant prevalence of dust particles in the atmosphere chiefly consisting of basic cations. pH of individual months of monsoon season reveals that in June and July rainfall is predominantly basic in nature while in August and September some instances of acid rain has been observed at Nagpur. Acid rain problem seems to be more acute in the month of March and December when pH in these two months falls below 5.0. High conductivity values during pre-monsoon season could be attributed to higher dust concentrations in the atmosphere during this period. An inverse relationship of form Y = AR^-B has been found between the constituents and rainfall.

7 tables, 3 illus, 12 ref

022198   Sahu M.;Nandankar P K (Meteorological Centre, , Raipur (C.G.) - 492 006) : Spatial and temporal variation of summer monsoon rainfall over Chhattisgarh during the period 1901-2000. Mausam 2006, 57(4), 679-83.

4 tables, 2 illus, 4 ref

022197   Ravikumar D;Ravindrasingh G;Umesh B N; Chikkaramappa T (Karnataka State Remote Sensing Application Center (KSRSAC), , Bangalore-560 034) : Identification of suitable bore/open well points using remote sensing and geophysical methods. Envir Ecol 2006, 24(4), 710-13.

Ground water occurs in all the geological formations of the state. The principal aquifer in the state are constituted mostly by the weathered and fractured granites, gneisses and Schist as the hard crystalline rocks with the lack of primary porosity. Vesicular, weathered and fractured basalts constitutes aquifer of limited potential. The sedimentary rocks namely sand stone, shale and limestone have lost their primary porosity considerably and hence do not form potential aquifers. Alluvium, occurring along some of the rivers and streams and their tributaries also constitute important aquifers, through of limited thickness and lateral extent. Remote sensing data helps in delineating the potential ground water occurrence zone with less time and cost effective manner than the conventional methods. The thematic layers on (geology, geomorphology, drainage, hydrology, structures, soil and land use generated from satellite data, are essential in identifying the ground water prospect zones. Geophysical, investigations adopting electrical resistivity methods are being carried out by the Karnataka State Remote Sensing Applications Center of the Department of IT and BT, in different districts of Karnataka State. To delineate the vertical variations along the depth, like thickness of the over burden, depth to bed rock, depth to fracture, drilling depth, geophysical survey was carried out. Electrical resistivity survey method has selected where 'Schlumberger Array Technique was adopted to analyze the resistivity variation along different vertical horizons.

1 table, 4 illus, 3 ref

022196   Ramteke R S;Subba Rao C;Ghosh N (Central Water and Power Research Station, , Pune) : Geophysical investigation for detection of cavities at dowlaiswaram arm of Godavari anicut, Andhra Pradesh. J Geophys 2006, 27(3), 53-7.

Geophysical investigations comprising potential gradient profiling, Schlumberger profiling and seismic refraction survey were carried out at Dowlaiswaram arm of Godavari anicut, Andhra Pradesh to detect cavities, if any, under the masonry structure of the anicut. Two continuous gradient profiles and seven Schlumberger profiles were taken on the downstream side of the anicut in Cistern 1 and 2. Six seismic refraction profiles were also taken in Cistern 2, where high resistance zone was delineated by electric 1 survey. The result of potential gradient profile indicated three weak zones/cavities in Cistern 1 and two in Cistern 2. The existence of these weak zones at the same place was also confirmed by Schlumberger profiling method. The result of seismic refraction, survey did not show any weak zone/cavities which may be due to a low velocity zone lying under high velocity layer.

5 illus, 4 ref

022195   Ramesh M V;Sudhakar M (National Centre for Antarctic and Ocean Research, Ocean Development De, , Headlandsada, Vasco-da-Gama,Goa-403 804) : Identification of paleo-beaches of holocene off kalingapatnam-pentakota shelf, east coast of india using 'C' statistics as a tool - a first report. J Indian Acad Geosci 2006, 49(1), 39-44.

Seventy eight (78) surficial sediment samples of varying water depths ranging from depths from 17 to 200m isobath off Kalingapatnam-Pentakota shelf, East coast of India have been subjected to granulometric studies. Mean, Standard deviation, Skewness, 1 -percentile ("C" statistics) and Median values have been derived from the grain size analysis. In the present study, an attempt has been made on the isopleth map of "C" statistics of the sediment samples to delineate the drowned strand lines (still stands of the Holocene).

4 illus, 33 ref

022194   Patil M N;Sinha S (NO, Indian Institute of Tropical Meteorology, Pune) : Soil temperature distribution with vegetation and rainfall over semi-arid region of western India. Mausam 2006, 57(4), 688-94.

1 table, 8 illus, 9 ref

022193   Pati J K;Malviya V P;Prakash K (Earth and Planetary Sciences Dep, Nehru Science Centre Univ, Allahabad-211 002) : Basement reactivation and its relation to neotectonic activity in and around Allahabad, Ganga Plain. J Indian Soc Remote Sens 2006, 34(1), 47-56.

The study of lineament pattern based on IRS-IA sub-scene (P24-R50) and Landsat (P 143-R42) data combined with the drainage analysis and field observations, two prominent sets of lineament (NE-SW and NNW-SSE), besides less prominent E-W and N-S trending lineaments of tectonic origin have been observed in parts of Allahabad area. Pervasive and penetrative sub-vertical joint sets parallel to the macroscopic linear structures along with collapse structures possibly of neotectonic origin are also noted in the basement rock exposed to the SSW of Allahabad. The development of various meso- and macroscopic deformed structures, presence of collapse structure in the basement strata and the near orthogonal channel shift of axial rivers provide evidence of basement reactivation in parts of Allahabad area, Ganga plain in space and time.

7 illus, 22 ref

022192   Oza S R;Singh R P;Dadhwal V K (Space Applications Centre (ISRO), , Ahmedabad) : Characterization of vegetation fraction estimated using spot-vegetation NDVI data for regional climate modeling in India. Mausam 2006, 57(4), 669-74.

Vegetation fraction (VF) is an important input in mesoscale climate models, such as MM5. The most commonly used VF inputs in modeling is the climatic monthly VF generated by Gutman and Ignatov (1998) (GI) using NOAA-AVHRR NDVI global data sets. Reports the generation of 1 km VF data set using SPOT-VEGETATION 10-day composite NDVI products from April 1998 to November 2003 for the Indian region. Sensor-specific thresholds of NDVI associated with 0% and 100% VF for SPOT-VEGETATION were found to be 0.04 and 0.804, respectively, in contrast to 0.04 and 0.52 of GI. Comparison of derived VF with climatic VF of GI was carried out. Analysis of VF for three latitudinal zones (<60>16, 16-24, <62>24) indicated the differences up to 15 percent from GI. Significant difference was observed for the area having rain-fed agriculture. Results of the seasonal and year-to-year variations of derived VF are discussed.

6 illus, 16 ref

022191   Naresh Kumar;Ahmad N;Bhowmik S K Roy;Hatwar H R (India Meteorological Dep, , New Delhi,) : Wave drag by two-dimensional mountain lee waves. Mausam 2006, 57(4), 591-6.

A linear hydrostatic model of a stably stratified air-stream flow over a two-dimensional orographic barrier is considered assuming wind increases linearly with height and stability is constant. Analytical expressions for mountain drags and momentum fluxes are obtained for Assam-Burma hills as well as Western Ghats of India. The general expression for mountain drag also obtained for both the ridges of Assam-Burma hills.

3 illus, 16 ref

022190   Nandankar P K;Srinivasan G;Satya Kumar M; Bhagat D K U R (Regional Meteorological Centre, , Nagpur) : Reliability study of wwatch III model during 21st to 29th may 2001 cyclone over the arabian sea. Mausam 2006, 57(4), 695-700.

4 illus, 24 ref

022189   Mokashi D D;Khadtare S V;Jadhav J D (Zonal Agricultural Research Station, Mahatma Phule Krishi Vidyapeeth, Solapur-413 002) : Nakshtrawise rainfall variability and probability analysis for drought prone areas. Bioinfolet 2007, 4(1), 1-5.

Rainfall analysis of nine different places of scarcity zone was carried out. The rainfall data as per the availability of last 40 to 49 years was used for Nakshtrawise and Decadal analysis for Drought Prone Areas of Maharashtra. In northern part at Dhule, <62>50 mm rainfall was received in Mrugashira to Magha nakshtra with less variability (CV <60>100). In central part, the rainfall in Mrugashira nakshtra at Kopergaon and Rahuri and Aaridra nakshtra at Kopergaon have less variability (CV <60>100) in kharif season. In norhthern part at Dhule, Mrugashira to Purva nakshtras have the highest probability (<62>50%) while, Purva nakshtra has the highest initial probability (73%). In central part, the highest initial probability (<62>50%) of rainfall in Mrugashira nakshtra was only at Rahuri. In southern part, the initial probability of getting <62>50% rainfall was in Mrugashira nakshtra at Mohol in kharif season.

2 tables, 7 ref

022188   Misra K S (NO, Geological Survey of India, Nagpur, Email: ddgcr_ngp@sancharnet in) : Tectonic history of major geological structure of peninsular india and development of petroliferous basin and eruption of deccan and associated volcanics. J Geophys 2006, 27(3), 3-13.

Study highlights the salient features and tectonic history of major geological structures which transact the Peninsular India. These structures include grabens and rifts as well as lineament and tectonic zones. They seem to have played very significant role in development of sedimentary basins which host coal bearing Gondwanas and marine petroliferous Mesozoic and Tertiary rocks. Evidences are provided to suggest that these Structures mainly experienced continued extensional tectonics since Proterozoic times. This extensional tectonics resulted in development of elongated basins along them. Other characteristic features invariably associated with these structures are high relief and heat flow, high density of lineaments with associated neotectonic and seismic activity as well as gravity and magnetic anomalies. Deposition of very thick sedimentary sequences culminated in volcanism both during upper Proterozoic and upper Mesozoic times. Volcanism appears to be due to decompressional melting related to basinal faults progressively reaching to the critical depths. Melting of lithosphere generated felsic lavas in the initial phase, followed subsequently by typical tholeiitic flows. In areas where these structures are found to be intersecting each other, much thicker deposition of sedimentary rocks and more pronounced volcanism have taken place due to the compounding effects of extensional tectonics. Further, high heat flow, high density of lineaments and enhanced neotectonism and seismicity are also noticed in the vicinity of intersectional areas. The present author believes that these compounding effects are very significant not only in development of depocentres but also in supply of organic material from continental areas to these deltaic regions. Apart from this, the upwelling heat along associated downward progressing extensional faults both before and after the volcanism was largely responsible for providing the kitchen for distilation of oil, both during the Mesozoic and Tertiary times. Furthermore, he suitability of trap rocks as cap rock in formation of Mesozoic oil traps is also suggested.

7 illus, 18 ref

022187   Meena G S;Bhosale C S;Jadhav D B (NO, Indian Institute of Tropical Meteorology, Pashan, Pune-411 008, Email: gsm@tropmet.res.in) : Retrieval of stratospheric O₃ and NO₂ vertical profiles using zenith scattered light observations. J Earth Syst Sci 2006, 115(3), 333-47.

Daily zenith scattered light intensity observations were carried out in the morning twilight hours using home-made UV-visible spectrometer over the tropical station Pune (18°31', 73°51') for the years 2000-2003. These observations are obtained in the spectral range 462-498 nm for the solar zenith angles (SZAs) varying from 87° to 91.5°. An algorithm has been developed to retrieve vertical profiles of ozone (O₃) and nitrogen dioxide (NO₂) from ground-based measurements using the Chahine iteration method. This retrieval method has been checked using measured and recalculated slant column densities (SCDs) and they are found to be well matching. O₃ and NO₂ vertical profiles have been retrieved using a set of their air mass factors (AMFs) and SCDs measured over a range of 87-91.5° SZA during the morning. The vertical profiles obtained by this method are compared with Umkehr profiles and ozonesondes and they are found to be in good agreement. The bulk of the column density is found near layer 20-25 km. Daily total column densities (TCDs) of O₃ and NO₂ along with their stratospheric and tropospheric counterparts are derived using their vertical profiles for the period 2000-2003. The total column, stratospheric column and tropospheric column amounts of both trace gases are found to be maximulm in summer and minimum in the winter season. Increasing trend is found in column density of NO₂ in stratospheric, tropospheric and surface layers, but no trend is observed in O₃ columns for above layers during the period 2000-2003.

1 table, 8 illus, 30 ref

022186   Masanta S;Roy G B;Tarafdar P K (Soil & Water Conservation Dep, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur-741 252, Email: shyamdulal_masanta@yahoo co in) : Evaluation of hydro-sociological parameters in rural and urban areas of Haringhata block in Nadia district (WB). Envir Ecol 2006, 24(4), 850-3.

Investigation was carried out during the year 1998-1999 in rural and urban areas of Haringhata block in Nadia district, (WB) to study the availability, pattern and sources of water in rural and urban areas and to classify the water utilization pattern according to socio-economic and occupational status. The result reveals that the average annual rainfall of this area (19 years average) was 1,564 mm and the maximum amounts of rainfall occur during June to September. The average RH varies from 65.33 to 85%. The water source of the rural people were pond, dug well, khal, beel, jheel etc., whereas the urban people in addition to the mentioned source most of them also use pipe water. The rural people did not bother about the water pollution and treatment system whereas the urban communities used to take some remedial measure. The urban communities used more water for sanitation purpose than the rural community. But for agriculture and other works, the water use was higher in rural areas. The rural people were not satisfied for the water supply system whereas urban people were moderately satisfied. Among all the sources deep tube well and rainwater quality were better for drinking purposes than all other sources with respect to chemical and microbial qualities.

7 tables, 2 ref

022185   Manimaran G;Ravindran A (School of Tectonics, Geology Dep, V.O. Chidambaram College, Tuticorin-628 008, Email: acugemmani@yahoo.co.in) : Caution on forthcoming Volcanogenic Tsunami in Indian Ocean. Res J Chem Envir 2007, 11(1), 19-22.

Tsunamies are generated due to sudden displacement of vertical sea water column during the events of earthquakes [Magnitude<62> 7 ], eruptions of submarine and coastal volcanoes, sudden slumping of marine sediments, land slides near the coast, the large meteor impact on sea from space and manmade nuclear explosion in the sea. Recently on 26 December 2004, a destructive Tsunami of Indian Ocean was generated due to the second largest earthquake of the world ever recorded (Magnitude 9.3) which occurred at off the west coast of Northern Sumatra. Subsequently on 28 March 2005 a weak tsunamigenic but great earthquake of magnitude 8.7 occurred at western shelf region of Northern Sumatra. Northernly moving thousands of after-shocks of December 2004 earthquake. up to Burma border and Southeasternly moving hundreds of after shocks of March 2005 earthquakes occurred upto Java are still going on and releasing tremendous energy along this seismic belt. The couplet of the great earthquakes and their aftershocks were triggered eruptions of inland volcanoes like Talang volcanoof Central Sumatra and of Barren Volcano of Andaman. A chain of hundreds of active volcanoes are seen along the Andaman - Indonesian Volcanic Arc System. It is a right time to remember the tsunamigenic, violent explosion of Krakatau Volcano on 27 August 1883, which was triggered due to the Tsunamigenic Car Nicobar earthquake (Magnitude 7.9) occuring on 31 December 1881 and had its aftershocks upto August 1883. On considering the above scenario, it is possible for a consecutive great earthquake of December 2004 and March 2005 with their ongoing aftershocks to trigger and explode anyone of the submarine volcanoes of the Andaman - Indonesian Arc System. As a result, a Volcanogenic Tsunami may be generated in Indian Ocean probably before the end of the year 2007 or in near future.

2 illus, 11 ref

022184   Londhe A L;Patil S D;Kumari B Padma;Jadhav D B (NO, Indian Institute of Tropical Meteorology, Pune) : Ozone variation pertaining to dry and wet monsoon seasons over Indian region. Mausam 2006, 57(4), 663-8.

Monthly mean total column ozone (TCO) over Indian region for the years 1982, 1983, 1987 and 1988 has been utilized to study the TCO distribution during dry and wet monsoon years. TCO data for 13 Indian stations for the above years have been considered in the study. Comparison of TCO distribution during dry and wet monsoon years suggested that TCO values are found higher during dry years than those in wet years. The changes in TCO may be attributed to difference in convective activity during dry and wet years. The suppressed (enhanced) convection during dry (wet) years may lead to increase (decrease) in TCO. The statistical test is applied to test the significance of TCO difference during monsoon months between dry and wet years. The difference is statistically significant at 5% level of confidence for all stations except Dumdum. It can be said that the relation between OLR and TCO holds good during Indian summer monsoon months, as convection is stronger during this period.

2 tables, 2 illus, 23 ref

022183   Lal R P (India Meteorological Dep, , New Delhi, India) : Short period climatology of Maitri, schirmacher oasis, East Antarctica. Mausam 2006, 57(4), 684-8.

2 tables, 4 illus, 5 ref

022182   Kulkarni A V;Dhar S;Rathore B P;Babu Govindha Raj K;Kalia R (Marine and Water Resources Group, Space Applications Centre (ISRO), , Ahmedabad-380 015) : Recession of Samudra tapu glacier, Chandra river basin, Himachal Pradesh. J Indian Soc Remote Sens 2006, 34(1), 39-46.

Himalayas possess one of the largest resources of snow, ice and glaciers that act as a huge freshwater reservoir. Monitoring the glaciers is important to assess the overall reservoir health of the Himalayas. Samudra Tapu is one of the largest glaciers in Chandra basin of district Lahaul and Spiti, Himachal Pradesh. Based on the field investigations and the remote sensing techniques, features such as accumulation area, ablation area snowline/equilibrium line, moraine-dammed lakes and permanent snowfields were mapped. The glacial terminus was identified using moraine-dammed lake, as lake is located at down streamside of the terminus. The total recession of glacier during the period of 38 years (1962-2000) is about 742 m with an average rate of 19.5 m/yr. In addition, glacial extent is reduced from 73 to 65 km² between 1962 and 2000, suggesting overall deglaciation of 11%. During field investigation, three stages of glaciation using terminal moraine were identified. These moraines were mapped by merging LISS-III and PAN data. At the peak of glaciation, the glacial terminus was extended 3.18 km downstream of terminus position in year 2000. Total area during peak of glaciation period has been observed to be 77.67 km", which is 12.67 km² higher than the present glacier extent.

2 tabels, 6 illus, 18 ref