015151   Roy A;Srivastava V K (NO, Indian Institute of Remote Sensing (ISRO), Dehradun-248 001, Email: arijitroy@iirs.gov.in) : Geospatial approach to identification of potential hotspots of land-use and land-cover change for biodiversity conservation. Curr Sci 2012, 102(8), 1174-80.

Human-driven land-use and land-cover change (LULCC) is one of the most important causes for depletion of biodiversity. Few studies have been undertaken to spatially identify the natural areas prone to LULCC and hence biodiversity loss. This article describes a geospatial modelling technique using a combination of drivers of LULCC, spatial distribution of LULCC and topographic impedances for change in hotspot. A study has been carried out to establish the model. The model has shown that the natural areas having high population density in the vicinity are highly prone to LULCC.

5 illus, 3 tables, 26 ref

015150   Rawat S;Phadtare N R;Sangode S J (NO, Wadia Institute of Himalayan Geology, Dehra Dun-248 001, Email: sangode@unipune.ac.in) : Younger dryas cold event in NW Himalaya based on pollen record from the Chandra Tal area in Himachal Pradesh, India. Curr Sci 2012, 102(8), 1193-8.

Pollen record of an AMS radiocarbon dated lacustrine sediment profile underlying the Chandra peat deposit in Himachal Pradesh, yielded signatures of the globally reported Younger Dryas (YD) cold event. This report of the YD event in NW Himalaya, substantiated by mineral magnetic variations, also records significant wet and warm conditions prior to 12,880 cal yrs BP, depicting the Alterod interstadial preceding YD. The notable decrease in local (meadow) and regional (desert steppe) vegetation indicates major climate shift towards cold and dry conditions marking the onset of YD that intensified progressively till 11,640 cal yrs BP. The YD terminates with gradual reappearance of local and regional flora, indicating initiation of the Holo-cene wet and warm conditions. The pollen-inferred floristic changes and mineral magnetic variations suggest that in NW Himalaya the initiation and termination of the YD cold event was probably gradual.

3 illus, 25 ref

015149   Ravi Kumar M;Hazarika P;Srihari Prasad G; Singh A;Saha S (NO, National Geophysical Research Institute (CSIR), Hyderabad-500 007, Email: kumar_mr1@rediffmail.com) : Tectonic implications of the september 2011 Sikkim earthquake and its aftershocks. Curr Sci 2012, 102(5), 788-92.

This study presents results of the spatial patterns of 292 aftershocks of the Mw 6.9 Sikkim earthquake of September 2011, accurately located through analysis of three component waveforms registered by a five station broadband network operated immediately after its occurrence. Refined hypocentral parameters achieved through application of the hypoDD relocation scheme reveal tight clustering of events along a NW-SE trend with focal depths reaching <126> 60 km. These trends viewed in conjunction with the strike-slip mechanisms of past earthquakes in Sikkim, including the main shock, affirm the predominance of transverse tectonics in this segment of the Himalaya where the Indian plate convergence seems to be accommodated by dextral motion along steeply dipping fault systems.

6 illus, 15 ref

015148   Rao P S;Rao N S (Geology Dep, Andhra Univ, Visakhapatnam, Email: srnandipati@gmail.com) : Quality of groundwater in coastal region of Andhra Pradesh, South India. J appl Geochem 2014, 16(1), 81-90.

A study on groundwater quality has been carried out in parts of coastal region of Andhra Pradesh, South India, where groundwater is a major source for drinking and irrigation. The area is underlain by rocks representing the Eastern Ghats (khondalites, charnockites etc), over which the river alluvium occurs. The results of pH, EC, TDS, TH, Ca²⁺, Mg²⁺, Na⁺, K⁺, HCO₃^-, Cl^-, SO^2-₄, NO^-₃ and F^- suggest that the quality of groundwater is of alkaline nature with fresh to brackish and controlled by rock-weathering, mineral dissolution, ion exchange and evaporation. Poor drainage conditions and chemicals from agricultural fertilizers degrade the groundwater quality. In many locations, the quality of groundwater is not suitable for drinking with reference to TDS, TH, Mg²⁺, Na⁺, Cl^-, NO₃^- and F^-, while it is not good for irrigation with respect to USSL's diagram. Thus, the study suggests management measures to improve the groundwater quality.

3 illus, 2 tables, 26 ref

015147   Rao K S P;Viswanathan S (NO, , 1-2-98, Kakatiyanagar, Habsiguda, Hyderabad, Email: ksprao1939@yahoo.co.in ) : Wavelength-dispersive X-ray fluorescence spectrometric determination of cadmium in zinc ores. J appl Geochem 2014, 16(1), 91-5.

Zinc ores are known to contain significant amounts of cadmium. The paper proposes a simple, accurate, precise, rapid, and non-destructive wavelength-dispersive x-ray fluorescence spectrometric technique for determining cadmium in zinc ores. The technique uses a sequential x-ray fluorescence spectrometer, 100 kV - 80 mA - 3kW x-ray generator, tungsten x-ray tube, LiF 220 analysing crystal, fine (150 μm) collimator, air path, scintillation counter, and short counting times. The accuracy of the technique is excellent (within 2 percent). The precision is also excellent (within 2 percent). The lower limit of detection is 3 ppm. The time taken for determining cadmium in a batch of twenty four samples of zinc ores, for a replication of four analyses per sample, by one operator, using a manual wavelength-dispersive x-ray fluorescence spectrometer, is only eight hours.

2 illus, 1 table, ref

015146   Rajendran C P (NO, Centre for Earth Sciences, Indian Institute of Science, Bangalore-560 012, Email: cp.rajendran@yahoo.com) : Disaster management: need for an aggressive strategy. Curr Sci 2012, 102(5), 658-9.

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015145   Raj Bala (NO, Post Graduate Government College, Sector-46, Chandigarh-160 047, Email: rajbalakaushik2004@yahoo.co.in) : Impact of human population on water resources: a case study of Rajiv Gandhi Chandigarh Technology Park, Chandigarh. South Asian Anthrop 2013, 13(1), 1-7.

Present research was done to investigate the impact of human population on water resources with special reference to Rajiv Gandhi Chandigarh Technology Park (RGCTP), Chandigarh. The various parameters regarding water quality was studied experimentally. Samples were collected for testing the chemical characterization of the ground water. Ground water was collected in two periods, One, in the month of June (pre-monsoon sample collection), and the other in the month of October (post-monsoon sample collection) because these two periods are ideal for obtaining information on the maximum concentration of various constituents present in surface water. After analyzing the various parameters (conductivity, pH, TSS (Total Suspended Solids), TDS (Total Dissolved Solids), turbidity, COD (Chemical Oxygen Demand), nitrate nitrogen, oil and grease, phosphate, sulphate, alkalinity, ammonical nitrogen, chloride, calcium, fluoride, total hardness and magnesium) of water quality it was found that there was no change in water quality due to the RGCTP. After calculating the domestic water requirements for the RGCTP, it was concluded that the RGCTP was exerting burden on the ground water aquifers, which were being tapped to meet the water demand. The water level in the tube wells had gone down drastically due to excessive use of underground water and as no canal water was available for I.T. (Information Technology) Park.

3 tables, 11 ref

015144   Purohit R;Bhu H;Mehta P (Geology Dep, Govt. College, Sirohi, Rajasthan, Email: ritesh_purohit@rediffmail.com) : Contrasting carbonate lithofacies from the palaeoproterozoic lower Aravalli group, NW India. J appl Geochem 2014, 16(1), 1-10.

Carbonate litho-facies, located proximally in the Lower Aravalli Group (LAG) of northwest India, are deciphered by contrasting geochemical characters. In the LAG, the carbonates from the underlying Babarmal Formation are calcitic while the carbonates of the overlying Jhamarkotra Formation are dolomitic. The calcitic carbonates show 85% average carbonate content as compared to the dolomitic carbonates which reportedly show 55% average carbonate content. Similarly, Mg values in the studied calcitic carbonates are about 1.2wt% which is considerably low as compared to the 10wt% Mg in the dolomitic carbonates. The calcitic carbonates do not bear phosphate and related organic bio-markers like the dolomitic carbonates. Unlike the dolomitic carbonates the calcitic carbonates do not show significant replacement of Ca⁺⁺ ions by Fe, Mg and Mn ions and hence retain better pristine geochemical features. Mg/Ca (0.024) and Fe/Mn (0.25) for calcitic rocks are low in contrast to the dolomitic carbonates where Mg/Ca (0.53) and Fe/Mn (from 0.5 to 2) are high. These low values of the ratios for the calcitic carbonates suggest that there was very low influx and their deposition took place under considerable restricted conditions as compared with the dolomitic carbonates. This inference is further confirmed from high positive Ce anomalies in the dolomitic carbonates. The calcitic carbonates show average Sr value of 80 ppm which is less than the average concentration of 100 ppm in dolomitic carbonates. Sr values for both the carbonates are much low and lie within small range which indicates that source for both the carbonates was uniform. 1000Sr/Ca facies variation ratios crowd between 0.25 and 0.75 which indicate typical shelf environment for both calcitic and dolomitic carbonates. Calcitic carbonates unlike dolomitic carbonates invariably show low Mn/Sr ranging from 0.8 to 2.5 that suggests that the samples are diagenetically unaltered and imply that the carbonates bear the original depositional features inherited from the coeval seawater that-was perhaps depleted in Mn. Significant differences in the geochemical compositions between two contrasting carbonate litho-facies indicate different palaeo-environment and provenance.

4 illus, 3 tables, 24 ref

015143   Patankar V;D'Souza E;Kumaraguru A K;Arthur R (NO, Nature Conservation Foundation, 3076/5, IV Cross, Gokulam Park, Mysore-570 002, Email: vardhan@ncf-india.org) : Distance-related thresholds and influence of the 2004 tsunami on damage and recovery patterns of coral reefs in the Nicobar Islands. Curr Sci 2012, 102(8), 1199-1205.

The earthquake and tsunami of 2004 resulted in the devastation of marine and coastal ecosystems across the Indian Ocean. However, without adequate baseline information it has been difficult to properly gauge its full impact. The reefs of the Nicobar Islands in the Bay of Bengal lie on a path that ranges from 190 to 500 km from Banda Aceh, the epicentre of the 2004 tsunami. In 2008, we recorded benthic damage as a result of the tsunami to reefs off 14 Nicobar Islands across a gradient of distance from the epicentre. A clear pattern was observed in the demographic structure of the most abundant coral genera, Acropora and Forties across the distance gradient. Significantly, for the largest coral individuals of both genera (<62> 50 cm diameter), there were distinct threshold effects - their abundance declining dramatically in reefs closer than 350 km from the epicentre. Corals between 20 and 50 cm diameter also increased with distance from the epicentre, but in a more linear fashion. Smaller size classes either showed no apparent trend (Acropora) or decreased linearly (Porites) with distance. These genera represent very different life-history strategies: Acropora is fast-growing and highly susceptible to a range of disturbances, while Porites typically grows slowly but is resistant to disturbance. The fact that both genera showed similar thresholds indicates that, close to the epicentre, the impact of the earthquake and tsunami was large enough to override any species-specific resistance. Also, algal cover was also much higher than at locations further north, linked to higher coral mortality at these locations. However, the fact that smaller size class coral individuals were relatively abundant and even increased close to the epicentre indicates possible paths of reef recovery after the catastrophe.

4 illus, 1 table, 35 ref

015142   Panigrahy S;Murthy T V R;Patel J G;Singh T S (NO, Space Applications Centre (ISRO), Ahmedabad-380 015, Email: murthytvr@sac.isro.gov.in) : Wetlands of India: inventory and assessment at 1 : 50,000 scale using geospatial techniques. Curr Sci 2012, 102(6), 852-6.

Conservation and wise use of wetlands has been given priority world over. India harbours diverse types of wetlands. This study highlights the findings of the national-level inventory and assessment of wetlands carried out using RESOURCESAT-1 LISS-III data of 2006-07 at 1:50,000 scale. A hierarchical system comprising 19 classes based on Ramsar definition has been used to classify the wetlands of India. The extent of wetlands has been estimated to be 15.26 m ha. Inland wetlands account for 69.22% (10.564 m ha), whereas the coastal wetlands account for 27.13% (4.14 m ha). The high-altitude wetlands (situated <62> 3000 m asl) in the Himalayan states were also mapped, comprising 126,249 ha of areal extent. The status of wetlands in terms of water spread, turbidity of open water and aquatic vegetation has shown significant variation during pre- and post-monsoon seasons. This article highlights the detailed results at state level and the status of wetlands in terms of water spread, aquatic vegetation and turbidity of open water in the wetlands in the pre- and post-monsoon seasons.

2 illus, 1 table, 7 ref

015141   Pandey A C;Nathawat M S;Ghosh S (Remote Sensing Dep, Birla Institute of Technology, Mesra, Ranchi-835 215, Email: arvindchandrap@yahoo.com) : Morphometric control on glacier area changes in the Great Himalayan range, Jammu and Kashmir, India. Curr Sci 2012, 102(8), 1188-93.

Authors have utilized satellite images of 1975 and 2001 to reveal the slow response of glaciers to climatic warming in the Great Himalayan Range, Jammu and Kashmir, India. Correlation of various glacier mor-phometric parameters with reference to glacier area change and shift in the snout position revealed that morphometric parameters exert prime control on area changes over glaciers, but do not have much control on the snout retreat or advancement of glaciers. The snout of glaciers which possess low relief may witness more retreat and vice versa. Percentage of area loss was higher over smaller glaciers indicating significant sensitivity of smaller glaciers to area changes.

5 illus, 4 tables, 27 ref

015140   Nayak S;Mandal M (NO, Centre for Oceans, Rivers, Atmosphere and Land Sciences, Indian Instit, Kharagpur-721 302, Email: mmandal@coral.iitkgp.ernet.in) : Impact of land-use and land-cover changes on temperature trends over Western India. Curr Sci 2012, 102(8), 1166-73.

Study the regional variation of temperature trends (warming or cooling) over Western India and the contribution of land-use and land-cover (LULC) changes towards this warming or cooling based on temperature datasets of 37 years (1973-2009). The contribution of LULC to the warming or cooling is estimated based on deviation in temperature in the observation and re-analysis datasets. The observed temperature dataset indicates that Western India is getting warmer by 0.13°C per decade. This warming is the combined effect of increase in concentration of greenhouse gases and LULC changes. The impact of LULC changes on temperature trends over Western India is estimated using 'observation minus reanalysis' method. The results indicate that the LULC changes have contributed to warming over this region by 0.06°C per decade. Comparison of the change in temperature trend with the change in LULC indicates warming due to LULC changes because of the reduction of area under open forest and subsequent increase of the area under agricultural land. The study highlights the impact of land-use change to be more significant and the utility of satellite data for periodic LULC studies in climate change research.

3 illus, 3 tables, 30 ref

015139   Mittal S;Biswas S;Singh K (Civil Engineering Dep, IIT, Roorkee) : Applications of geocells in cohesionless soil an experimental study. Wat Energy int 2012, 69(4), 47-55.

Discusses the improvement in bearing capacity of square footing placed at cohesionless soil reinforced with Geocell. Mohr - Coulomb failure criterion was used in the observations. To study effects of geocells with respect to planar geogrid, tests were conducted on planar reinforcement also. Numerical analysis results obtained by PLAXIS have been compared with those obtained from experiments and were found to be in good agreement. A parametric study revealed the role of length of reinforcement, spacing between layers, placement of reinforcement from top surface etc. on bearing capacity. A design example has been given to illustrate the savings in cost of construction of footing on reinforced sand. The study shows that improvement in bearing capacity with respect to unreinforced soil is of the order of 86% and settlement reduction is 13.07% for single layer of geocells which for double layers of geocells is 693% and 86.48% respectively. The cost reduction is 23.5% with respect to unreinforced soil.

8 illus, 5 tables, 13 ref

015138   Mitra D S;Bhadu B (NO, K.D.M. Institute of Petroleum Exploration, ONGC, 9, Kaulagarh Road, Dehradun-248 195, Email: dsmitra@gmail.com) : Possible contribution of river Saraswati in groundwater aquifer system in Western Rajasthan, India. Curr Sci 2012, 102(5), 685-9.

River Saraswati is believed to have flown through the Thar Desert, as reconstructed by several experts based on critical data gathered by them. A careful observation of the channel shows that in most of the places these are fault-controlled. Studies of palaeochannels in many parts of the world proved successful in identifying high-yielding freshwater zones. Presence of fault system accelerates the recharge process and down-flow of water gets maximized through fault planes during the wet period. The present work is an attempt to emphasize the contribution of palaeo Saraswati River to goundwater exploration in drought-prone areas of western Rajasthan.

6 illus, 24 ref

015137   Kumar T S;Nayak S;Kumar P;Yadav R B S;Kumar A;Sunanda M V;Devi E U;Shenoi S S C (NO, Indian National Centre for Ocean Information Services, Hyderabad-500 055, Email: srinivas@incois.gov.in) : Performance of the tsunami forecast system for the Indian ocean. Curr Sci 2012, 102(1), 110-4.

The Indian Tsunami Early Warning System (ITEWS) at the Indian National Centre for Ocean Information Services, Hyderabad, is responsible for issuing tsunami bulletins in India. The tsunami centre operates on a 24 x 7 basis and monitors seismological stations, bottom pressure recorders and tidal stations throughout the Indian Ocean to evaluate potentially tsunamigenic earthquakes and disseminating tsunami bulletins. The end-to-end capabilities of this warning system have been well proven during all the tsunamigenic earthquakes that occurred since September 2007. Comparison of the earthquake parameters estimated by ITEWS with other international seismological agencies suggests that the system is performing well and has achieved the target set up by the Intergovernmental Oceanographic Commission.

2 illus, 2 tables, 18 ref

015136   Kocherla M (NO, National Institute of Oceanography (CSIR), Dona Paula, Goa-403 004, Email: kocherla@nio.org) : Authigenic carbonates in the sediments of Goa offshore basin, Western continental margin of India. Curr Sci 2012, 102(8), 1205-11.

Euhedral crystals (approx 1 mm) of authigenic carbonates are identified in 5 m long sediment cores collected from the western continental margin of India in water depths between 2665 and 3070 m. Low-Mg calcite and aragonite are the dominant authigenic minerals while high-Mg calcite, dolomite and siderite occur in minor amounts. Morphological evidences such as euhedral carbonate crystals and slender radiating aragonite crystals suggest that they are formed authigenically in the sediment column. The delta13C values of the authigenic carbonates range between 0.63% and -8.12%, and is attributed to the contribution of isotopically light carbon derived from the oxidation of sedimentary organic matter in the surficial sub-oxic Fe reduction and the bacterial sulphate reduction zone during early diagenesis. Mineralogy, morphology and stable carbon isotope signatures of authigenic carbonates and the occurrence of pyrite framboids and octahedral crystals and the evaluation of pore-fluid chemistry are not indicative of enhanced methane flux. They argue against a precipitation of carbonates due to anaerobic oxidation of methane and refute the possible connection of methane gas from the shallow gas-charged sediments to the observed carbonates.

3 illus, 1 table, 54 ref

015135   Jain S K;Kumar V (Water Resources Development and Management Dep, Indian Institute of Technology, Roorkee-247 667, Email: s_k_jain@yahoo.com) : Trend analysis of rainfall and temperaure data for India. Curr Sci 2012, 102(1), 37-49.

This article aims to review studies pertaining to trends in rainfall, rainy days and temperature over India. Sen's non-parametric estimator of slope has been frequently used to estimate the magnitude of trend, whose statistical significance was assessed by the Mann-Kendall test. Spatial units for trend analysis vary from station data to sub-division to sub-basin/river basins. There are differences in the results of the various studies, and a clear and consistent picture of rainfall trend has not emerged. Although the different units (sub-basins or sub-divisions) may have a nonzero slope value, few values are statistically significant. In a study on basin-wise trend analysis, 15 basins had decreasing trend in annual rainfall; only one basin showed significant decreasing trend at 95% confidence level. Among six basins showing increasing trend, one basin showed significant positive trend. Most of the basins had the same direction of trend in rainfall and rainy days at the annual and seasonal scale. Regarding trends in temperature, the mean maxi-mum temperature series showed a rising trend at most of the stations; it showed a falling trend at some stations. The mean minimum temperature showed a rising as well as a falling trend. At most of the stations in the south, central and western parts of India a rising trend was found. Some stations located in the north and northeastern India showed a falling trend in annual mean temperature. Most of the data used in trend analysis pertained to the stations located in urban areas and these areas are sort of heat islands. This article also highlights the need of a network of baseline stations for climatic studies.

4 illus, 2 tables, 80 ref

015134   Hegde G V;Subhash Chandra K C (Mines and Geology Dep, , No. 49, Khanija Bhavan, Race Course Road, Bangalore-560 001, Email: hegdegv@gmail.com) : Resource availability for water supply to Bangalore city, Karnataka. Curr Sci 2012, 102(8), 1102-4.

^ssc1 illus, 1 table, 7 ref

015133   Dhir R P;Singhvi A K (NO, , No. 498, Defense Colony, Jodhpur-342 009, Email: dhirrp08@gmail.com) : Thar desert and its antiquity. Curr Sci 2012, 102(7), 1001-8.

For long, widely divergent views (based on isolated pieces of historical evidence or broad geological evolution of the subcontinent, notably the rise of the Himalayas in mid-late Miocene), had prevailed regarding origin and antiquity of the Thar Desert. Studies of the past few decades have since provided a wealth of new information on landform styles, evolutionary processes and palaeoclimate history with chronometric and isotopic constraints. Salt lakes, dunes and calcrete-bearing alluvial aggradations have been the focus of interest. This review synthesizes the multidisciplinary work to present the state of the Thar during the Quaternary period. Studies on salt lakes have provided high-resolution palaeoclimate records, but of the past approx 15 ka BP only. Strong aeolian activity is a characteristic of the latest 200-300 ka period and is marked by several episodes of greater aridity, strong wind regime and sand dynamism followed by periods of stability implying climate amelioration and some pedogenesis. However, the preceding mid and early Quaternary periods are marked by alluvio-colluvial and sheetwash aggradation with pronounced, well-evolved calcretes therein. These findings strongly suggest that for much of the Quaternary period, the Thar region enjoyed a semiarid climate and the desertic conditions came to dominate much later.

3 illus, 77 ref

015132   Dhawan G;Patni B D (NO, , NPHC Ltd) : Stability of spillway cutslope at Dhauliganga H.E. project. Wat Energy int 2012, 69(4), 28-35.

The understanding of hill slope stability in the construction of hydro project depends upon the realistic approach of Geological investigation & cautious construction procedure. The careful appraisal and analysis of geotechnical data helps to chalk out the strategies for coping with various slope failures. Excavation of 150m high spillway cut slope of Dhauliganga project experienced various geotechnical problems due to complex geological setup and adverse topographical conditions. With successful application of state of the art technology, the problems were conquered with success. The high angle spillway cut slope necessitated with progressive change in the design of spillway by reducing its width and utilization of diversion tunnel as spillway tunnel. For the first time in Himalayan terrain, a reinforced anchored drift was constructed to stabilize the vulnerable spillway cutslope. The present paper deals with the several geological problems faced during the excavation of 150m high spillway cut slope of 280 MW Dhauliganga Project, St-I (Uttarakhand) and its remedial measures.

17 illus, 3 ref

015131   Dees M;Straub C;Koch B (Remote Sensing and Landscape Information System Dep, Albert-Ludwigs Freiburg Univ, 79085, Freiburg, Germany, Email: matthias.dees@felis.uni-freiburg.de) : Can biodiversity study benefit from information on the vertical structure of forests? utility of LiDAR remote sensing. Curr Sci 2012, 102(8), 1181-7.

Light detection and ranging (LiDAR) remote sensing offers new and improved capabilities for vertical and structural characterization of objects, such as plant height and different growth stages/strata, etc. Climate change will change tree and plant growth conditions and thus will change forest structure and distribution, which can potentially be studied using LiDAR remote sensing. LiDAR data were acquired during leafless season that was subjected to generation of digital terrain model, digital surface model, vegetation height model, forest height map, top height of forest stands, detection of gaps, detection and mapping of tree stands, mapping of density classes of middle layer and understorey detection of coniferous trees. The stand height and structural information derived from the LiDAR imagery would greatly contribute to the characterization of biodiversity through vertical stratification.

4 illus, 2 tables, 10 ref

015130   Datta A;Kamal (Earth Sciences Dep, Indian Institute of Technology, Roorkee-247 667, Email: kamal.iitr@gmail.com) : Trigerring of aftershocks of the Japan 2011 earthquake by earth tides. Curr Sci 2012, 102(5), 792-6.

The aftershock sequence of the devastating Japan earthquake of March 2011 is analysed for the presence of periodicities at the Earth tide periods. We use spectral analysis as well as a time-domain method, KORRECT, developed earlier to detect the presence of diurnal and semi-diurnal periodicities in the sequence of aftershocks (M ≥ 4). This suggests that large aftershocks in the fault zone of the Japan 2011 earthquake were strongly influenced by Earth tides.

5 illus, 17 ref

015129   Arya V S;Sandeep Kumar;Singh H;Anil Kumar; Hooda R S;Arya S (NO, Haryana Space Applications Centre (HARSAC) Haryana Agricultural Univ, Hisar-125 004, Haryana) : Wastelands change analysis using multi-temporal satellite data in arid zone of Haryana. Curr Trends Technol Sci 2014, 3(1), 60-4.

India shares 16% of the world population, while its land is only 2% of the total geographical area of the world. Naturally, the pressure on the land is often beyond its carrying capacity. Therefore, the productive lands, especially the farmlands in the India are in the constant process of various degrees of degradation and are fast turning into wastelands. At present, approximately 68.35 million hectare area of the land is lying as wastelands in India. Out of these lands, approximately 50% lands are such non-forest lands, which can be made fertile again if treated properly. It was unprotected non-forestlands, which suffered the maximum degradation mainly due to the tremendous biotic pressure on it [1]. In the present study Wasteland change analysis in four district of South-Western Haryana Bhiwani, Rewari, Mahendergarh & Mewat was carried out. IRS-IC/ID LISS-III digital data for three seasons i.e. Kharif, Rabi and Zaid for the year 2008-09 was used for interpretation of the wastelands in the state adopting WGS-84 datum and UTM projection system. The interpretation and analysis of satellite data was carried out by using on-screen interpretation technique on 1:35000 scale. The vector data of wastelands generated during 2005-06 was also used to generate change detection matrix in the districts. The total wastelands changes during the year 2005-06 to 2008-09 occur in form of wasteland to non wasteland, new wastelands or non wasteland to wasteland and one wasteland class to another wasteland class.

3 illus, 3 tables, 6 ref

013933   Zelikman E;Carmina E (Geography and the Human Environment Dep, Tel-Aviv University, Ramat Aviv, Tel-Aviv 69978, Israel, Email: eugenyzel@gmail.com) : The spectral response characteristics of the soils and their possible estimation by using partial least square regression (PLSR) analysis. Int J Geomatics Geosci 2013, 3(3), 438-53.

The objective of this study was to investigate the potential of diffuse reflectance spectroscopy technique to predict several important soil parameters such as soil moisture (SM), hygroscopic water (HW), soil carbonates (SC) and specific surface area (SSA) through descending layers of the soil stratigraphy. For these purposes a field spectrometer (Analytical Spectral Device, ASD) with a probe (sub-surface spectral head device - 3S-HeD) for reading subsoil reflectance data were used. 145 samples, taken from different Israeli soils at different depth and a spectral library containing laboratory and field in-situ collected spectra (by using 3S-HeD device) were used to generate calibration and validation models in the study based on the Near Infrared Analysis (NIRS). These models were generated by the correlation between spectral characteristics and chemical soil properties separately for each soil property, using partial least square regression (PLSR) analysis.The regression coefficients between measured and predicted values of the soil properties varied between 0.93 and 0.99 in the calibration and validation stages, RMSE (Root Mean Square Error) between 0.09 and 4.6, which showed that NIRS method had potential to accurately predict these attributes in soils. Even though the prediction results for SSA are relatively poor (RMSE varied between 27 and 30) accurate linear relationships between the laboratory measured and predicted values exist (it is seen by high correlation r values in the calibration and validation stages). In addition, to predict studied properties down the profile by using 3S -HD device, eighteen drill holes locations were selected from the surface IS-based map within the semi-arid agricultural area, using clustering isodatamethods. For each drill holes ten layers were spectrally measured down to 100 cm depth. The results we got from the spectroscopic analysis were logical given the environmental conditions. Further research is needed to compare our results with chemical lab tests of the same soil samples, and to repeat this study in other locations. This new approach is worth investing in as it is cost effective for such a variety of applications currently required.

9 illus, 1 table, 38 ref

013932   Venkat Raman A T V R;Gurugnanam B;Arunkumar M (Centre for Applied Geology, Gandhigram Rural Institute-Deemed University, , Email: geoatvr@gmail.com) : One decade hydro meteorological data assessment through statistics, Dindigul district, Tamil Nadu, South India. Int J Geomatics Geosci 2013, 3(3), 659-67.

The study has been made to detail an account on the environment through rainfall for the area of dindigul using meteorological data for recent decade from the collected data of the Indian Meteorological Department (IMD). All the seasons does not given significant difference in it whereas there is an important note that in 2003 winter were accounted abnormal before the tsunami year 2004 in dindigul. However there could not be a notable relation to the area, the abnormal changes on season in a particular time before a natural process has to be view focused. The graphical methods are clearly revealed the characteristics of rainfall in season wise, annual, and in month wise to brief them in it. Through the histogram curves, it have explained the distribution of the rainfall by the seasons and revealed that monsoon and winter distributed positively. Month wise classifications shown the importance of denser details could enable the broad view of understanding. The correlation implemented that there was a negative relationship with all the seasons among each other. The sudden change in a particular year and season migration has to be looking through properly by monitoring with more importance to prevent the future. Harvesting rain in the monsoon and when ever good rain, could be a moderate to the area. Depletion in climate change has to be to make aware to prevent and predict for the future.

9 illus, 9 ref

013931   Vaidya N;Kuniyal J C;Chauhan R (G. B. Pant Institute of Himalayan Environment and Development, Himacha, , Mohal-Kullu-175 126, Email: jckuniyal@gmail.com) : Morphometric analysis using Geographic Information System (GIS) for sustainable development of hydropower projects in the lower Satluj river catchment in Himachal Pradesh, India. Int J Geomatics Geosci 2013, 3(3), 464-73.

Remote Sensing and Geographic Information System (RS&GIS) techniques are effectively being used in recent times as an important tool in determining the quantitative description of morphometry of a basin. This technique characterizes very high accuracy of mapping and measurement of morphmetric analysis. The aim of the present study is therefore to analyze the GIS based morphometric activities of the Lower River Satluj catchment including parts of Kinnaur, Shimla, Kullu, Mandi and Bilaspur districts in Himachal Pradesh, India. Morphometric analysis of drainage system requires delineation of all existing streams. Based on GIS morphometric assessment, buffer zone of 10 km either of the River Satluj was identified. This area is lying from northeast to southwest from Nathapa village in Kinnaur district to Bilaspur town in Bilaspur district. The total length of River Satluj included under present study was 165 km. The total length of stream segments is maximum under first order streams and this length decreases as the stream order increases. It is also observed that there is a decrease in stream frequency as the stream order increases. It is observed that low drainage density is in the lower Satluj catchment. With the help of GIS, it is observed that highest number of streams shows the maximum opportunities for the hydroelectric power projects in the middle Satluj catchment. While the lower drainage density indicates that the catchment has permeable sub-soil.

4 illus, 4 tables, 24 ref

013930   Singh A N;Singhal A;Gupta R (Civil Engineering Dep, BITS-Pilani, Rajsthan, Email: arunnihal14@rediffmail.com ) : A small discussion on microwave application for groundwater exploration. Int J Geomatics Geosci 2013, 3(3), 474-85.

This review article presents the electromagnetic (EM) technique are the most common implemented methods by geophysicist for mineral exploration. The use of EM technique in environmental and engineering application is also established, especially in detection of contaminant plumes and exploration of waste sites in recent. Throughout the globe, the EM is used for groundwater related studies along with its mother work in mineral exploration. Airborne EM is appropriate for large scale and efficient groundwater surveying. Due to dependency of the electric conductivity on different material present (as clay, rock, water, sand) in the host body and the mineralization of the water. EM system are suitable for providing information of the aquifer structure, and water quality respectively.

^iia2 illus, 2 tables, 40 ref

013929   Santra Mitra S;Santra A;Mitra D (School of Geography and Environment, University of Southampton, Hampshire, Southampton, Email: shreyashi.mitRa@gmail.com) : Change detection analysis of the shoreline using Toposheet and Satellite Image: A case study of the coastal stretch of Mandarmani-Shankarpur, West Bengal, India. Int J Geomatics Geosci 2013, 3(3), 425-37.

Change detection helps in ascertaining shoreline trend analysis and its future prediction. In this study, the coastal tract of the part of West Bengal, which is sensitive to rapid shoreline change is chosen. Applying remote sensing and GIS techniques on the multi-temporal satellite image and topo-sheets, shoreline extraction using water index and subsequent change detection analysis have been carried out to assess the erosion-accretion pattern in the region at both regional and local scale. Depending on the erosional pattern, the entire study area was divided into four erosional-cells, and independent study was carried out in different cells. The results exhibit that this coastal region has been experiencing erosion. Excluding the contribution of inland water bodies, it has been estimated that between 1950 and 2005, a vast stretch of the land has been engulfed by the sea-water. This clearly signifies the necessity of coastal zone protection measures to be implemented in the area.

5 illus, 4 tables, 26 ref

013928   Panda R K;Nagarajan R (Center of Studies in Resources Engineering, IIT Bombay, Bombay, , Email: rajatcsre@iitb.ac.in) : Prioritization of sub-basins of Ghataprabha River using morphometric parameters. Int J Geomatics Geosci 2013, 3(3), 605-17.

Drainage morphometric analysis of river basins indicates the prevailing hydrological processes. Drainage lines of the Ghataprabha River, has been demarcated from SRTM DEM and substantiated with the thematic maps. Geographical Information System (GIS) was used in integrating the data and geo-referencing. Areal, linear, drainage length and density and relief parameters were determined. Surface storage potential of individual sub-basins was assessed using the morphometric and terrain parameters and prioritized for development.

5 illus, 3 tables, 15 ref

013927   Muthukrishnan A;Aruchamy S;Banukumar K; Alaguraja P (Civil Engineering Dep, Ponnaiyah Ramajayam College of Engineering Technology, Anna University, Vallam,Thanjavur, Tamil Nadu) : Climatic balance on coastal ecosystems in Gulf of Mannar: Geoclimatic techniques. Int J Geomatics Geosci 2013, 3(3), 668-91.

This paper describes the coastal ecosystem were drawn from remotely sensed data and checked the doubtful areas in the field. Tuticoirn coastal zone has been classified into three major origin of ecosystems such as Fluvial,(deep buried pediment, natural levee, river, alluvial plain, flood plain, deltaic plain and delta), Fluvio-Marine identified in the study area are estuary and shoal and Marine origin (sandy plain, coastal plain, beach ridge-swale complex, stabilized dune, coastal dune, sandy beach, marine terrace, spit, cliff, sand bar, creek, salt flat, mud flat, tidal flat/tidal inlet, tombolo, island, lagoon/paleo lagoon, and coral reef) based on theoretical explanations and image interpretation elements. The region's climatic trends are consistent with those of other parts of the world.

8 illus, 3 tables, 19 ref

013926   Murugiah M;Venkatraman P (Manonmaniam Sundaranar University, , Tirunelveli, Tamil Nadu, Email: murugit@yahoo.com) : Role of Remote Sensing and GIS in artificial recharge of the ground water aquifer in Ottapidaram taluk, Tuticorin district, South India. Int J Geomatics Geosci 2013, 3(3), 405-15.

The problem of the present study is a representative case of over exploitation of groundwater resources, leading to the continuous exhaustion of the grained as well as the groundwater aquifers. The application of the increasingly and internationally accepted method of artificial recharge on the groundwater aquifer was decided to be the most effective for the restoration of balance of the hydrogeological system. Deep knowledge of the details of the geological structure and the hydrogeological conditions of the area is necessary for the success of the method, whose planning has to be made based on the principles of environmental protection and sustainable development. Use of state-of-the-art technology and estimation of all the parameters involved, which are necessary, have been taken into account. Keep this as an objective to identify the suitable sites for artificial recharge zones.

7 illus, 6 tables, 11 ref

013925   Jana T K;Lahiri S;Samadder A K;Mitra P K; Sengupta D;Jyoti Prakash Kumar (Geological Survey of India, Research & Analysis Div, 27, Jawaharlal Nehru Road, Kolkata-700 016, Email: tkjana60@gmail.com) : Creek systems of th western Sunderbans with special reference to appraisal of the georesources of the tidal domain. Indian J Geosci 2012, 66(1), 49-64.

An understanding of the evolution in georesources within the tidal domain could be made through closer appreciation of tidal landforms relating to creek systems. Historically and traditionally, landform units of tidal regime of the Sunderbans have collectively been looked upon as resources for both survival and livelihood. A change in hydraulic regime of the tidal system over last several centuries is manifested in creek systems and hence the quality of the micro-landform units and pattern of their utilisation has witnessed major transformation. With deterioration of discharge along trunk channel of Ganga River, the downstream drainage network and tidal creeks were flushed only with tidal flows. Thus the creek systems, many of which were earlier haying sufficient draught for large vessels to ply, had been abandoned and a similar fate followed for some of the ancient habitations. Major changes in land use practices in Sunderbans during British period brought new settlements and the process of building up of land in the intertidal marshes by tide-borne silts carried by creeks was arrested. The creeks further witnessed shallowing of channel beds, changes in configuration of channel bars and tidal flats. The georesources of creeks and associated landforms went through modifications partly due to anthropogenic interference and because of natural instability of the tracts. The study by Geological Survey of India in recent years (2005-2009) indicates that many of the creeks and minor cross channels show rapid deterioration in the north, while outfall points of major creeks show extensive modifications in channel morphology. Various in-channel landforms including channel bed geometry, tidal flats, mid-channel shoals and bars and creek margins have been studied extensively during the survey and their resource potential assessed. As the trend of changes in tidal domain is complex in nature, flexibility in landform- resource utilisation and principle of sequential land use practice should be incorporated in perspective planning of landform-georesources of this fragile domain at land-sea interface. The present study aims at bringing together geological history of the trunk river (Bhagirathi) and the evolution of creek systems of Sunderbans into abroad framework of tidal georesource potential-a step towards this objective.

15 illus, 10 ref

013924   Ghosh S;Chakraborty I;Bhattacharya D;Bora A; Ashok Kumar (Engineering Geology Div, Geological Survey of India, Esatern Region, Block DK 6, Sector II, Kolkata-700 091, Email: saibal.springdale@gmail.com) : Generating field-based inventory of earthquake-induced landslides in the Himalayas- an aftermath of the 18 september 2011 Sikkim earthquake. Indian J Geosci 2012, 66(1), 27-38.

The 18 September 2011 Sikkim earthquake (M: 6.8) induced large number of landslides in the Sikkim-Darjeeling Himalayas. For mapping these event-based landslides, a post-event field survey was conducted, which identified 210 earthquake-induced landslides that occurred proximal to major roads. Out of these, 196 are "new" and the rest are reactivated landslides. These landslides occur within varying elevations, slopes and are of varied types starting from debris slides to rockslides and rock fall. Field studies revealed that rockslides and rock fall are generally predominant in the higher elevations of North Sikkim, an area proximal to the epicentral region. These rockslides and rock fall occur mostly within the steep and inaccessible slopes, proximal to ridge crests, for which mapping using the field-based techniques alone is difficult. This study thus demonstrates that for achieving a near-completeness of any event-based landslide inventory, a two-fold mapping technique is necessary, relying both on remote sensing methods and field surveys. The availability and use of good quality pre- and post- event high-resolution air photos and/or satellite images coupled with selected field surveys can render a comprehensive picture about the existence of those event-based landslides, which are required for estimating the seismically induced landslide hazards and risks in such active geo-environment.

8 illus, 2 tables, 52 ref

013923   Ghosh S C (NO, , Flat No. 7NE, Green View, 119, Southern Avenue, Kolkata-700 029, Email: scg.ghosh@gmail.com) : Overview of fossil conchostraca of Indian Gondwana and new contributions to Gondwana geology in global context. Indian J Geosci 2012, 66(1), 1-26.

Non-marine micro-biota is rare and very valuable in geological record as it is susceptible to environmental changes in the terrestrial part of a continent. Important palaeoenvironmental interpretations are made from studies on terrestrial fauna which are also helpful for palaeobiogeographic interpretations. Conchostraca, broadly referred as 'estheriids,' is a paraphyletic term of the suborder Spinicaudata within Phylum Arthropoda and is an important terrestrial Crustacea. Several time-restricted and environment-indicative taxa found in the Indian collection help in establishing ten biostratigraphic horizons or Estheriid-biozones within the Indian Gondwana sequence. Contribution of scanning electron microscopy (SEM) is of considerable importance in studies related to ontogenetic changes in chitinous valve taxometry and carapace ornamentation. New laboratory techniques involving SEM and other phylogenetic analysis have enriched primary data base, for the first time. Field studies on basin analysis of one Gondwana basin, Raniganj Coalfield as a test case in the present study, along with tectonic set up of the basin has enabled unfolding the geological history of the basin during the Permo-Triassic (P/T) transition zone. REE and trace element profiles have been carried out across the undisturbed lithological boundary between the Raniganj and the Panchet formations as encountered in boreholes drilled in the eastern part of Raniganj Coalfield. Samples collected from the borehole cores were fresh and least affected by surface contamination yielded better geochemical results under Neutron Activation Analyses, There are however, some excellent index fossils which help to distinguish the Late Permian and Early Triassic faunal assemblages which in turn help to demarcate the Permo-Triassic (P/T) boundary. Moreover, majority of taxa in this group of fossils appear to be resilient to changes in environment like salinity, temperature, water current and nature of the mud substrate, which in turn caused endemic fossils to appear in the assemblage. Biostratigraphic correlation, on the basis of the estheriid biozones, enables us to carry out intra- and inter- basinal correlation within the subcontinent. Bivariant taxometric comparison suggests proximity of the Indian block with the European plate during P/T transition zone. Height and length of fossil carapaces of Indian fauna and those of other countries indicate a striking similarity among some taxa suggesting a circum -Tethyan land and/ or near-shore migratory route for these taxa between the northern and the southern continents of Pangaea. All these new data throw light in palaeogeographic reconstruction of 'Gondwanaland'.

2 illus, 2 tables, 69 ref

013922   Bhattacharya B;Bhattacharya H N (Geology Dep, Hooghly Mohsin College, Chinsurah, Hooghly-712 101, Email: hbaruamu@gmail.com) : Implications of mud-clast conglomerates within late palaeozoic talchir glaciomarine succession, Talchir basin, India. Indian J Geosci 2012, 66(1), 69-78.

Reworked proglacial coarser elastics overlain by post-glacial, storm tide- influenced, transgressive shoreface-shelf sediments characteristically frame the Talchir sedimentary succession (Permo-Carboniferous) of the Talchir Basin, peninsular India. Mud-clast conglomerate, a common but relatively less appreciated feature from siliciclastic sequences, occurs in three distinct horizons within this succession. Episodic passage of seismic shocks, triggered possibly by the glacio-isostatic adjustments of the underlying crust, is considered responsible for cracking and fragmentation of the cohesive, unconsolidated mud layers at or below the sediment-water interface, and producing the flat clasts. Subsequent emplacement of the clasts to form mud-clast conglomerates attests to processes associated with basinal tectonisms induced by Late Palaeozoic glaciation-deglaciations in the ice-marginal Talchir Basin.

6 illus, 38 ref

013921   Bhatt S C;Mahmood K (Geology Dep, Institute of Earth Sciences, Bundelkhand Univ, Jhansi, Email: geoscb@yahoo.com) : Deformation pattern and microstructural analysis of sheared gneissic complex and mylonitic metavolcanics of Babina-Prithipur sector, Bundelkhand massif, Central India. Indian J Geosci 2012, 66(1), 79-90.

Study area broadly consists of three major groups of rocks: i) Bundelkhand Gneissic Complex of Archaean (3.3 Ga) to Palaeoproterozoic age, ii) metasedimentaries and metavolcanics (2.56 Ga) and iii) granitoids of Precambrian age (2.5Ga). The basement constituting mafics and streaky gneisses and associated with small lensoidal bodies of mafics, ultramafics, amphibolites and quartzite was subjected to three phases of folding in three tectonic episodes (D₁-D₃). The small- to large-scale crustal shear zones were developed during various stages of progressive brittle-ductile shearing in syntectonic phase (D₄). The quartz reefs were emplaced along NE-SW-trending major shear zones and followed by last magmatic intrusion of basic dykes along NW-SE-trending fractures and faults. In the present paper, detail structural and microfabric analysis is attempted to reconstruct structural model of the study area. A major E-W-trending crustal scale Taparyan-Papawni shear zone varying in width from 200 m to 500 m is traced in mylonitic metavolcanic rocks to the south of Taparyan village. The minor folding and crinkles were probably developed due to back rotation of axial planes and reorientation of fold axis during progressive shearing. The shear sense indicators, viz. asymmetrical and rotated porphyroclasts (σ_a and σ_b mantled clasts) of quartz, feldspar identified in protomylonite to mylonite zones on meso- and microscopic scale, exhibit dominant sinistral top-to-SW sense of shear movement. The presence of undulose extinction, deformation lamellae in quartz and feldspar grains reveal that the crystal plastic and strain-softening processes were dominant during evolution of mylonites under low- to medium- temperature conditions (400°-500°C). The occurrence of microfaults, extensional fractures and pull-apart structures in few grains of quartz and feldspar strongly support the overprinting of brittle deformation on ductile shearing in cataclastic and low-pressure conditions.

7 illus, 32 ref

013920   Abtahi S M;Safe A (Physical Geography Dep, Faculty of Geographic Sciences and Planning, Isfahan Univ, Islamic Republic of Iran) : Rain and temperature trends in Namak Lake Basin (Iran) during the last half-century. Int J Sci Nat 2012, 3(1), 137-46.

FAO in its last definition of desertification has cited climate as a main component of creation and development of desert. In this research monthly precipitation and temperature data during 1956 to 2005 have been gathered and rebuilt. Then average precipitation and minimum and maximum temperatures of six sub- basins of Namak Lake are calculated by using Thiessen method in Arcmap environment. To evaluate precipitation trends, Standard Precipitation Index was used. The trend of precipitation and temperature climatic components were examined based on parametric linear regression and non- parametric Mann-Kendall test. No significant trend was observed in standardized precipitation of Namak Lake basin and its sub basins, expect for Arak sub basin in which precipitation change trend was decreasing and significant. The examination of monthly precipitation showed that in Arak, Qharechai and Karaj sub basins we have encountered harsh drought during these 50 years. Minimum and maximum temperature changing trends were increasing and significant in most sub basins. Increase in Namak Lake temperature conform to world temperature increase, that its main reason can be related to green house gases, Especially in large cities include Tehran, Qom, Arak, Kashan, Hamedan and Qazvin.

17 ref

012900   Yadav S K;Chandola V K;Galkate R (Soil Water Conservation Engineering, Institute of Agricultural Sciences, BHU, Varanasi-221 005, Email: vkc_vns@yahoo.co.in) : Water availability assessment in Bina river basin under virgin flow conditions using flow duration curves. Envir Ecol 2012, 30(4), 1289-93.

The water availability study of Bina river basin in Madhya Pradesh state was carried out to estimate dependable flow at various probability levels at different time periods and to analyze the flow regime under virgin flow condition using Flow Duration Curve technique. The assessment of water availability is important for the planning of water allocation scheme in Bina river basin to meet its on-stream demands. From the study it was observed that the flow regime in Bina river had been existing in virgin condition. The study indicated that the Bina river is an intermittent river having flow during monsoon season only. Thus, the water use demands of the area cannot be fulfilled from Bina river with the water availability under the existing condition. The results indicated that Bina river has high dependable flow during July to September and highest in August. The dependable flow of 28.1 m³s at 70% probability level and 14.06 m³s at 90% probability level were observed in August. The annual water availability at 75% probability was estimated to be 432 MCM which indicated that there was ample opportunity for harvesting water dams in the river. The construction of dam or other artificial structure at Rahatgarh on the river to store water in monsoon season may be helpful to fulfill for water requirement during non-monsoon season. The stored water can be used for domestic, irrigation, industries, and recreation purposes.

2 illus, 3 tables, 4 ref

012899   Subrhamanyam M;Rao N V (Geophysics Dep, Andhra Univ, Visakhapatnam-530 003) : Interpretation of gravity and magnetic profiles in the Bay of Bengal and inferences on the anomalous crustal structure. J Geophys 2012, 33(3), 61-8.

Deals with the gross structure of magnetic crust as deduced along six transects across the Bay of Bengal. The broad variations in the oceanic basement depth, Curie Point geotherm depth and sea bed attitude in the Bay of Bengal are discussed in terms of anomalous crustal structure. Two W-E trending transects, of which one is in the vicinity of 15° N latitude and the other along 13° N latitude, besides two NW - SE trending and two SW- NE trending transects are considered. Oceanic basement and Curie Point geotherm depth are determined using spectral method and the results are found to be in good agreement with the free- air gravity based crustal models. The SW - NE transects revealed rise in sea bed and dipping magnetic basement towards NE while the Curie Point geotherm depth changes very little. Results of the investigation revealed similarity in the models of gross magnetic crust and those derived from free-air gravity data along the six transects across the Bay of Bengal.

5 illus, 17 ref

012898   Shyam A;Gohil B S;Basu S (Geophysical Parameters Retrieval Div (GRD), Atmospheric & Oceanic Sciences Group (AOSG), Earth, Ocean, Atmosphere,, Ahmedabad-380 058, Email: abhineetshyam@gmail.com) : Retrieval of water vapour profiles from radio occulation refractivity using artificial neural network. Indian J Radio Space Phys 2013, 42(6), 411-9.

Artificial neural network (ANN) technique has been used to derive water vapour pressure profiles in the troposphere from radio occultation data over India and adjoining region. A fully connected three-layer network, with one hidden layer, has been constructed and standard back propagation algorithm has been used to train the network. While month, latitude and vertical profile of refractivity/bending angle constitute the input vector, the water vapour partial pressure profile forms the output vector. Only the moisture-laden summer monsoon months of June, July, August and September of 2010 have been considered for developing the retrieval algorithm. There are 2120 input and output pairs, out of which 1696 pairs form the training set while the remaining pairs constitute the validation set. The retrieved profiles of water vapour pressures in the validation set have been compared with the corresponding COSMIC operational products of water vapour pressure profiles. The effectiveness of the algorithm is apparent from this comparison and also from the vertical profiles of bias and root mean square error (RMSE). The statistics show better performance of the algorithm with refractivity as one of the inputs than with bending angle. The RMSE in water vapour retrieval from refractivity is within 1.5-2 hPa compared to markedly higher values of 6 hPa when derived from bending angle. Additionally, the algorithm has also been tested in an independent year 2009 and the performance of the refractivity based retrieval has been found to be highly consistent in the year 2010, with RMSE within 1.5 hPa.

8 illus, 16 ref

012897   Sharma S;Chhipa R C (Chemistry and Centre for Air & Water Modeling Dep, Suresh Gyan Vihar Univ, Jaipur-302 025, Email: cawm@gyanvihar.org) : Interpretation of ground water quality parameter for selected area of Jaipur using regression and correlation analysis. J scient ind Res 2013, 72(12), 781-3.

Groundwater is an important source of water supply due to its relatively low susceptibility to pollution in comparison to surface water. Polluted ground water adversely affects the human health as well as environment. This paper assessed ground water quality index and regression analysis of selected area of Jaipur. Ground water samples collected from 12 different locations of South west area of Jaipur in dry season (April 2010). Results indicates that significant correlation and regression occur between IDS & EC (.996), IDS & Cl (.987), TDS & Na (.945), EC& Na (.948), Cl & Na (.936). i.e. Total dissolved solids (TDS) is an important physicochemical parameter of drinking water quality. The water quality index of the area in dry season was 123.76 indicate poor quality of water for drinking purpose.

3 tables, 18 ref

012896   Ojha M;Sain K (NO, National Geophysical Research Institute, Uppal Road, Hyderabad-500 007, Email: maheswar_ojha@yahoo.com) : Seismic velocities and estimation of gas-hydrates across A BSR from AVA modeling in the western continental margin of India. J Geophys 2012, 33(4), 87-91.

Bottom simulating reflector (BSR) commonly used marker for gas-hydrates investigation, has been identified by seismic experiment in the western continental margin of India (WCMI). Seismic velocities hold a key to understand the origin of BSR and for quantitative assessment of gas-hydrates. Showed a new approach of Amplitude Versus Angle (AVA) modeling to estimate seismic velocities across various reflectors including the BSR in the WCMI. The result reveals the P-wave velocity of 2.25 and S-wave velocity of 0.985 km/s above the BSR. This corresponds to a Poisson ratio of 0.382 and hydrate saturation of <126> 30%. The comparison of estimated P-wave velocity (1.77 km/s) above the hydrated sediment to that (1.78 km/s) below the BSR implies that the origin of BSR is mainly due to gas-hydrates.

4 illus, 12 ref

012895   Naskar D C;Das L K;Roy K K;Majumdar R K; Choudhury K (Central Geophysics Div, Geological Survey of India, Kolkata) : Re-examination of the crustal structure across Narmada-Son-Lineament (NSL), Madhya Pradesh, Central India using magnetotelluric and gravity modeling. J Geophys 2012, 33(3), 69-77.

The Narmada-Son-Lineament (NSL) in the Central Indian Shield (CIS) is a profound crustal discontinuity, reactivated several times in the geologic past with left lateral transcurrent motion. These episodic reactivations have produced many graben/horst structures. The bounding faults of some of these younger morphotectonic units viz. the Narmada South Fault (NSF), have produced earthquakes of (M 6.0) in Jabalpur and swarms of earthquakes in Pandhana. Abnormally high heat flow is seen over the Satpura horst, south of NSL. High heat flow is normally accompanied by higher crustal electrical conductivity at depth. This paper is an attempt to re-examine the crustal structure of the northern part of the CIS, through MT and gravity studies, over a few selected transects in the area.

7 illus, 1 table, 21 ref

012894   Murthy Y S;Sarma S V S;Murali S;Preeti M (NO, Osmania Univ, Hyderabad) : Geophysical study of the gas show area in the south western region of the proterozoic Cuddapah basin. J Geophys 2012, 33(3), 41-8.

In the western Cuddapah basin several bore wells were identified to be associated with methane gas gushing out along with the ground water in the Tadipatri area. In order to gain insights in to the subsurface structure and lithology in the gas show area, deep electrical soundings together with resistivity scanning along a 4.5 Km. long traverse was carried out. Magnetic field measurements were also carried out along the resistivity scanning traverse. The subsurface model obtained from the inversion of electrical data brought out in general a three layer structure with the top and the bottom layers being conductive (50-100 ohm.m) representing the Tadipatri shales and a middle intermediate moderately resistive layer (a few hundread Ohm.m) interpreted to be a hidden sill. The intermediate layer exhibited conspicuous discontinuities/breaks, which are also observed to be associated with well defined sharp magnetic anomalies. Interestingly all the bore wells located along the scanning traverse and which exhibited gas shows fall very close to these segments of breaks in the intermediate layer suggesting that these features represent fault/fracture zones. These structures are inferred to facilitate the outward movement of the gas that remained presumably trapped underneath with the sill itself acting as a cap rock. The area of gas shows falls over the unique "gravity high" in the south western region of the basin which is interpreted to be a zone of magmatic intrusion. It is inferred that the source for the observed gas shows has a generic link to the hidden magmatic intrusive feature which might have created conditions favourable for thermogenic origin of the CH₄ through low-temperature fluid-rock interactions in the crustal layers related to active magmatism and metamorphism.

5 illus, 1 table, 32 ref

012893   Mishra H P;Rai M K;Mishra S K;Singh A;Singh N;Singh R K;Singh S K (NO, , Geohysicist (Sr), GSI Complex, Sector-E, Aliganj, Lucknow-226 024) : Estimation of total dissolved solid in ground water of Tarai area of Shahjahanpur, Bareilly and Pilibhit districts, Uttar Pradesh. J Geophys 2012, 33(3), 79-83.

Tarai area of Ganga basin is a potential prospect for fresh ground water aquifer as it acquires fine/coarse sand beds under alluvium and Siwalik sediments. Deep electrical resistivity survey has demarcated fresh and saline water interfaces at deeper level. Unconfined shallower aquifer bears saline water whereas deeper confined aquifer contains potable water, underlain by thick zone of salinelbrackish water, Fresh and saline water have shown resistivities ranging from 20-45 Ohm-m and 2-10 Ohm-m respectively. The depth of the fresh and saline water interface has been interpreted as 1859m at Puranpur, 1944m at Shahjahanpur, 1050m at Baheri and 2600m at Nigohi. An analytical approach has been made to estimate the total dissolved solid in fresh water at deeper level, which falls between 150 and, 180 mg/lt of NaCI equivalent at the aquifer temperature. Under the prevailing geohydrological conditions the incursion of saline, water into the fresh water-bearing horizon cannot be ruled out due to over drawal of ground water in the area. This poses geoenvironmental hazards with regard to ground water management in the tract.

8 illus, 2 ref

012892   Khanna R K;Rao P S (NO, Oil and Natural Gas Corporation Limited, Mumbai, Email: psrao56@gmail.com) : Sea bed logging- a tool for risk mitigation in hydrocarbon exploration. J Geophys 2012, 33(4), 93-6.

Resistivity of the hydrocarbon saturated formation is significantly higher than the surrounding non-hydrocarbon bearing rocks. This property of hydrocarbon saturated rocks is made use of in identifying the subsurface resisivity anomalies using the Sea Bed Logging technology as a tool and accordingly the survey is designed. Large current of the order of thousand amperes generated onboard a vessel is discharged through the electrodes kept apart by few hundred meteres (source). The refracted electrical energy from the subsurface layers and the induced magnetic energy in the earth's magnetic field are measured by the receivers spaced at regular intervals along a profile while the source is moving from one end to the other end of the profile. The variations in the refracted electrical and magnetic energy measured and compared with that of a reference receiver kept closer to the survey area. The recorded data is plotted in amplitude Vs offset and phase Vs offset. Anomalies observed in the plots are carefully analysed and integrated with available seismic data to reduce risk, thereby improve the success ratio of the drilled locations.

11 illus, 3 ref

012891   Kamble R K;Rani C K;Ghosh N;Panvalkar G A (NO, Central Water and Power Research Station, Pune-411 024, Email: kamble_rk@cwprs.gov.in) : Acoustic and electrical logging for evaluation of resistivity and shear and compressional wave velocities of foundation of Kakrapur nuclear power plant. J Geophys 2012, 33(4), 101-4.

Construction of unit 3 and 4 of Kakrapar Atomic Power Project (KAPP) was proposed on the Deccan traps of Cretaceous age, comprising of mostly amygdaloidal basalt overlain by about 7 - 8 m thick silty soil. Electrical resistivity and shear and compressional wave velocities of subsurface formation were required to be assessed in situ for design of foundation of crucial structures like turbo-generator and reactor building of KAPP units 3 and 4. This paper deals with acoustic and electrical logging at KAPP for assessing nature of foundation and determination of in-situ shear and compressional wave velocities of subsurface rock. The resistivity and shear and compressional wave velocities thus determined were utilized for design of crucial structures of KAPP.

2 illus, 1 table, 4 ref

012890   Jaiswal R K;Eastogi B K (NO, Institute of Seismological Research, Sector 18, Gandhinagar-382 018, Email: brastogi@yahoo.com) : Next tsunami in India in the Arabian sea?. J Geophys 2012, 33(4), 111-5.

Future source zones of earthquakes that can generate tsunamis in the Arabian Sea are identified based on past seismicity and gap areas along subduction zones and zones of compression. These zones are Makran coast, Indus Delta and Kutch-Saurashtra region. The Makran subduction zone of Iran and southern Pakistan, situated on the northwestern side of the Arabian Sea, generates great but infrequent earthquakes, mud volcanoes and tsunamis. Indus delta of Pakistan has given rise to large earthquakes in the past. Kutch-Saurashtra region of India has prominent coastal faults. Past great and large earthquakes in Kutch have possibly generated local tsunamis. Based on the long-term assessment of large earthquakes in these regions it is inferred that tsunamigenic earthquakes can occur in near future in these regions.

3 illus, 1 table, 23 ref

012889   Gupta D;Banerjee B;Bhattacharya B B (GSI, SR, Hyderabad, Email: dineshguptagsi@yahoo.com.in) : Electrical and PEXMEL responses over a sulphide body in Shyami-ki-Dhani area, Sikar district, Rajasthan. J Geophys 2012, 33(3), 55-9.

Massive sulphide mineralisation with total sulphide content (TSC) about 25-30% in visual estimate was reported from the debri of a dug well dump near village Shyami-ki-Dhani in Neem-ka-Thana tehsil of Sikar district of Rajasthan. Integrated geological, geophysical and geochemical surveys were carried out in the area. In addition, to identify the type and abundance of metallic mineral present in the study area, PEXMEL (Partial Extraction of Metallic Ions by Electrolysis) survey was also carried out over the geophysical & geochemical anomaly zone. The results of the synergistic approach are presented in this paper. Results of PEXMEL survey over test traverse in this area are indicating 1025 NCC units for Zn over a background of 100 NCC units; and 150 NCC units of Pb over a background of 30 NCC units. A rock sample analyzed from well dump gives the following values: 1.3% Zn and 0.3% Cu. Surface Geophysical surveys employing electrical methods along with PEXMEL method were successful in identifying sulphide body's extension and type of metallic sulphide.

8 illus, 13 ref

012888   Dhar S K;Basu J (NO, Oil and Natural Gas Corporation Limited, Gujarat) : Direct detection of hydrocarbon by using marine controlled source electromegnetic sounding. J Geophys 2012, 33(4), 97-100.

Marine Controlled Source Electromagnetic Sounding (CSEM) is a geophysical exploration method which can identify buried resistive layers underlying deepwater conductive sediments. It is known from conventional petrophysics that hydrocarbon saturated sediments is having higher resistivity value than water saturated sedimentary rock. Therefore accurate identification of resistive sedimentary layer at the subsurface may detect directly a hydrocarbon pool. The present work addresses the problem of identifying the resistive layer by interpreting the CSEM response. Selection of suitable field specific data acquisition parameter is another point of concern in this work, to achieve noise free interpretable quality CSEM data. In this work, an attempt has been made to determine the field specific data acquisition parameter for a deep water exploration block situated at eastern coast of India. A set of synthetic model response curves are generated by simulating different possible values of acquisition parameters to select their applicable range of values for data acquisition. A 2D petrophysical forward model is constructed by considering the available geological information of the exploration block. CSEM response is then simulated over this field specific model with realistic data set. The forward model response clearly shows the presence of resistive layer buried in the conductive host rock. The response anomaly is further enhanced with increase in the resistivity contrast between the layers. The validity of the modeled response is compared with an actual CSEM response curve acquired from a field where the input geological information is kept same as that of the field. By knowing the exact cause of increase in resistivity within the sediments, one can conclude about the nature of fluid present within an entrapment.

7 illus, 6 ref