006441   Saikia M M;Sarma H P (Chemistry Dep, Dhing College, Nagaon, Assam, Email: mukutmonisaikia@yahoo.in) : Hydro-geochemical characterization of groundwater of Nagaon district of Assam, India. J Envir Res Dev 2011, 6(1), 41-50.

Hydrogeochemical studies were carried out in Nagaon district of Assam to identify and delineate the important geochemical processes which were responsible for the evolution of chemical composition of groundwater. The major cationic dominance pattern, is in the decreasing order of Ca<62> Mg<62> Na<62> K, Ca<62> Na<62> Mg<62> K, Na<62> Ca<62> Mg<62> K, Na<62> Mg<62> Ca<62> K, Mg<62> Ca<62> Na<62> K and Mg<62> Na<62> Ca<62> K respectively and the anionic concentration indicates that the majority of groundwater samples belongs to HCO₃<62> Cl<62> SO₄<62> NO₃ -type. The modified Piper diagram reflects that the water belongs to Ca²⁺-Mg₂₊-HCO₃, Na⁺-HCO₃^- and Ca²⁺-Mg²⁺-Cl^- -facies. The interpretation of plots for different major ions and molar ratios suggest that carbonate and silicate weathering controlled the hydrochemistry of the aquifer.

8 illus, 1 table, 31 ref

006440   Romshoo S A;Bhat S A;Rashid I (Geology and Geophysics Dep, Kahsmir Univ, Hazratbal, Srinagar Kashmir-190 006, Email: shakilrom@yahoo.com) : Geoinformatics for assessing the morphometric control on hydrological response at watershed scale in the upper Indus basin. J Earth Syst Sci 2012, 121(3), 659-86.

Five watersheds (W1, W2, W3, W4 and W5) in the upper Indus basin were chosen for detailed studies to understand the influences of geomorphology, drainage basin morphometry and vegetation patterns on hydrology. From the morphometric analysis, it is evident that the hydrologic response of these watersheds changes significantly in response to spatial variations in morphometric parameters. Results indicate that W1, W2 and W5 contribute higher surface runoff than W3 and W4. Further, the topographic and land cover analyses reveal that Wl, W2 and W5 generate quick runoff that may result in flooding over prolonged rainy spells. A physically based semi-distributed hydrologic model (soil and water assessment tool, SWAT) was used for simulating the hydrological response from the watersheds. As per the simulations, W5 watershed produces the highest runoff of 11.17 mm/year followed by W1 (7.9 mm/year), W2 (6.6 mm/year), W4 (5.33 mm/year) and W3 (4.29 mm/year). Thus, W5 is particularly more vulnerable to flooding during high rain spells followed by W1, W2, W4 and W3, respectively. Synthetic unit hydrograph analysis of the five watersheds also reveals high peak discharge for W5. The simulated results on the hydrological response from the five watersheds are quite in agreement with those of the morphometric, topographic, vegetation and unit hydrograph analyses. Therefore, it is quite evident that these factors have significant impact on the hydrological response from the watersheds and can be used to predict flood peaks, sediment yield and water discharge from the ungauged watersheds.

12 illus, 10 tables, 84 ref

006439   Reddy P R (NO, , 12-13-332, Street 12, Tarnaka, Hyderabad-500 017, Email: paravata@yahoo.com) : Historical development of seismic imaging technique. J Indian Geophys Union 2012, 16(3), 71-86.

Old scriptures mention that early studies carried out by Rishis/sages have helped in developing various tools and techniques to unravel the mysteries associated with the Earth. Recognition of the ensuing events of disaster like storms, cloudbursts, fire etc. by prehistoric man was mostly done through sound and light waves. Like in the present day, his understanding of disasters like earthquakes was limited, as he was not having requisite knowledge to probe the interior of the earth. It is mentioned in some old scriptures that the ancient man tried to guess the location and onset of earthquake activity, from the unusual behaviour of some animals and insects. Varahamihira mentioned in Brihat Samhita that earthquake prediction can be done observing abnormal cloud formations. Specific details of their studies need to be extracted from earlier scriptures, to add to our knowledge base. Even though sound waves have historically been used to understand vibrations of various frequencies, and to decipher signals coming from within the Earth, no systematic development in imaging the internal structure of the earth began until the mid 19th century. A concise exposition of the historical development of seismic imaging techniques is included in this article, to expose the reader to the focused studies carried out by eminent scientists of the 19th and early 20th centuries. The very fact that earlier studies combined theory and practice points out to the importance of these early studies and the strong scientific base they have created for subsequent developments. During the last 50 to 60 years considerable progress has been achieved not only in imaging basement structure but also sub basement crustal and sub crustal lithospheric structure. Theoretically supported experiments and their use in producing results help in holistically developing various scientific studies. Such a holistic development has been achieved in the seismic imaging of the subsurface formations extending from near surface depths to sub crustal columns. The basic objective in summarizing these chronological developments is to provide a broad understanding of the evolution and development of seismic imaging techniques (covering both analog and digital eras). Such an understanding is essential to properly use present day higher quality data acquisition and processing gadgets and would help producing high quality subsurface images, with time and space parameters as essential inputs. It is now well established that area specific attributes and time dependant variations alone can help in better understanding the intricate processes associated with subsurface structures and tectonics. The passive seismic based mega Arrays have indeed yielded excellent images of deep interior and provided useful information on the crust-mantle interactions. Global Array data and area specific 4-D seismic images of different dimensions, hopefully, would provide apt answers to many of the problems linked to the structure and evolution of the crust and sub crustal lithosphere.

^iia4 illus, 27 ref

006438   Rao V P;Anil Kumar A;Naqvi S W A;Chivas A R; Sekar B;Kessarkar P M (NO, National Institute of Oceanography, Dona Paula, Goa-403 004, Email: vprao@nio.org) : Lime muds and their genesis off-Northwestern India during the late quaternary. J Earth Syst Sci 2012, 121(3), 769-79.

Two sediment types were found in five gravity cores collected from water depths between 56 m and 121 m along the northwestern continental margin of India: lime muds were abundant in the lower section while siliciclastic sediments dominated the upper section. Lime mud-dominated sediments in shelf cores contained 60%-75% carbonate, 0.3%-0.6% Sr and terrigenous minerals, whereas those at the shelf break were found to have <62>90% carbonate, 0.6%-0.8% Sr and traces of terrigenous minerals. Aragonite needles showing blunt edges, jointed needles and needles wrapped in smooth aragonite cement were found to be common. Stable (O and C) isotopes of lime mud indicate a potentially freshwater contribution for shelf cores and purely marine contribution for those at the shelf break. Calibrated radiocarbon ages of the lime muds ranged from 17.6-11.9 ka in different cores. The results reported here suggest that the lime muds in the shallow shelf are probably reworked from the Gulf of Kachchh, whereas those at the shelf break were biodetrital, initially formed on the carbonate platform during low stands of sea level and then exported. The change in lime mud-dominated to siliciclastic-dominated sediments in the cores may be due to climate change and rapid rise in sea level during the early Holocene.

5 illus, 2 tables, 56 ref

006437   Rajendran K;Nanjundiah R S;Gadgil S; Srinivasan J (NO, Centre for Mathematical Modelling and Computer Simulation, Bangalore-560 037, Email: rajendrank@hotmail.com) : How good are the simulations of tropical SST-rainfall relationship by IPCC AR4 atmospheric and coupled models?. J Earth Syst Sci 2012, 121(3), 595-610.

The failure of atmospheric general circulation models (AGCMs) forced by prescribed SST to simulate and predict the interannual variability of Indian/Asian monsoon has been widely attributed to their inability to reproduce the actual sea surface temperature (SST)-rainfall relationship in the warm Indo-Pacific oceans. This assessment is based on a comparison of the observed and simulated correlation between the rainfall and local SST. However, the observed SST convection/rainfall relationship is nonlinear and for this a linear measure such as the correlation is not an appropriate measure and show that the SST-rainfall relationship simulated by atmospheric and coupled general circulation models in IPCC AR4 is nonlinear, as observed, and realistic over the tropical West Pacific (WPO) and the Indian Ocean (IO). The SST-rainfall pattern simulated by the coupled versions of these models is rather similar to that from the corresponding atmospheric one, except for a shift of the entire pattern to colder/warmer SSTs when there is a cold/warm bias in the coupled version.

10 illus, 1 table, 47 ref

006436   Papanna C;Nagaraju D (Studies in Geology Dep, Mysore Univ, Manasagangotri, Mysore-570 006, Email: Geopaps_06@yahoo.co.in) : Evaluation of groundwater resource potential using GIS in Kollegal taluk, Karnataka. J Ecotoxic envir Monit 2011, 21(1-2), 87-95.

Groundwater resources potential has been evaluated in Kollegal Taluk. Chamarajanagar district, Karnataka, using Geographic Information system (G1S) technique. It allows manipulation and analysis layer of spatial data. It is used for analyzing and modeling the interrelationship between the layers. Various thematic maps have been prepared for geology, geomorphology, slope, drainage density and lineaments of the study are using G1S techniques. These thematic maps have been integrated with the help of GIS. Appropriate weightage has been assigned to various factors controlling occurrence of groundwater to assess the total groundwater potential in each segment of the study area. The results show that there are five categories of groundwater potential ranging from very good to poor. The categorizations of groundwater potential zones are in general agreement with the available yield of 60 existing wells, bore wells and tube wells. This depicts the favourable prospective zones in the study area for evaluation of groundwater potential.

5 illus, 11 ref

006435   Mandal A;Ray A;Debnath M;Paul S P (NO, Presidency Univ, Kolkata-700 073, Email: rayarijit22@gmail.com) : Petrology, geochemistry of hornblende gabbro and associated dolerite dyke of Paharpur, Puruliya, West Bengal: implication for petrogenetic process and tectonic setting. J Earth Syst Sci 2012, 121(3), 793-812.

Paharpur gabbroic intrusive is an arcuate body running east-west paralleling the foliation of Chhota-nagpur Granite Gneiss which acts as country rock. The main gabbroic body is intruded by a number of dolerite dykes running north-south. It is composed of clinopyroxene (Wo₄₈En₄₀Fs₁₂-Wo₅₁En₄₀Fs₀₉, mg no. 72-82), plagioclase (An₅₂-An₉₀), hornblende (magnesian hornblende to ferro-tschermackite), orthopy-roxene (En₇₆-En₇₉) and ilmenite. Hornblende occurs as large poikilitic grain and constitutes around 60% of the rock. Both gabbro and associated dolerite dykes, show relatively primitive character (mg no. 65-73). Primitive mantle-normalized and MORB-normalized spider diagrams indicate enrichment in Rb, Ba, Th, La, Sr and depletion in Nb, Zr, Y, Ti and Nd. The LILE enrichment and Nb, Ti, Zr, Ydepletion suggest arc like geochemical signature for the gabbroic and doleritic rocks of Paharpur. Flat to slightly LREE fractionated pattern and variable degree of REE enrichment is observed. An early stage fraction-ation of clinopyroxene, plagioclase, orthopyroxene, ilmenite and late stage reaction of cumulate pile and evolved melt/hydrous fluid is suggested for magmatic evolution of gabbro. Associated dolerite dykes, which are geochemically similar to the gabbro, have tholeiitic with boninitic character. The mineralogi-cal and chemical compositions of intrusive rocks also have some similarity with mafic rocks of ophiolite complex of subduction zone.

14 illus, 7 tables, 62 ref

006434   Majumdar T J;Bhattacharya S (NO, Space Applications Centre (ISRO), Ahmedabad-380 015, Email: tjmajumdar@rediffmail.com) : Wintertime mapping and monitoring of sea ice temperatures surrounding Antarctica using SSM/I data. J Indian Geophys Union 2012, 16(3), 97-106.

Polar Regions are known to be highly sensitive to warming effects of the increased greenhouse gases. Sea ice, together with land ice, exerts profound influence in controlling the global climate. Mapping and monitoring of sea ice concentration and sea ice temperature around Antarctica during wintertime have been attempted here with NASA Team Algorithm. Results obtained concur well with those obtained by other workers. Major sea ice concentrations vary between 80-100% during August 2002 with more number of classes and sea ice temperatures are found in the range of 230 to 250 K.

5 illus, 22 ref

006433   Krishna Kumar S;Chandrasekar N;Seralathan P; Sahayam J D (NO, Centre for Geotechnology Manonmaniam Sundaranar Univ, Tirunelveli-627 012, Email: coralkrishna@yahoo.co.in) : Diagenesis of holocene reef and associated beachrock of certain coral islands, Gulf of Mannar, India: implication on cimate and sea level. J Earth Syst Sci 2012, 121(3), 733-45.

The reef and associated beachrock from certain Gulf of Mannar islands (Rameswaram, Kurusadai, Shingle and Appa Island) were studied to assess the diagenetic evidences. Sixty samples were collected from marine terraces and reef platforms. The samples comprised of coral rubbles, shell fragments and lithic fractions. The presence of corals in the form of framework or isolated patches on the reef flat suggests the rapid increase of accommodation and probably absence of terrigenous and siliciclastic inputs. Moreover, the massive coral heads above the transgressive phase suggest the maximum flooding and relatively deepest facies. The freshwater dissolution, association of marine and meteoric cements suggest the semi-arid climatic condition with marine diagenesis during sea level lowstands and recharge of freshwater lenses during periodic rainfalls. In addition, the interaction of these mixed carbonate, siliciclastic sediments results in silicification of carbonate components. The reef associated beachrock were deposited in low energy environment with some amount of terrigenous matters derived from Precambrian basement rocks and transported into reef area by ephemeral streams and longshore sediment transport. The incorporation of coral fragments within the siliciclastic sediments are most probably due to the erosion and re-deposition of the sediments.

8 illus, 24 ref

006432   Khan P K;Anand Mohan;Chowdhury S (Applied Geophysics Dep, Indian School of Mines, Dhanbad, Jharkhand, Email: pkkhan_india@yahoo.com) : Pre- and post-seismic activities along the Myanmar-Andaman-Sumatra subduction margin: insights for tectonic segmentation. J Indian Geophys Union 2012, 16(3), 87-96.

Spatial variation of the occurrences of large and great earthquakes along the subduction margin can be linked with various plate tectonics parameters viz. converging plate velocity vector, plate obliquity, age of the subducting plate, depth of plate flexing and inter-plate coupling. Present study addresses many of these parameters for understanding the seismotectonic status along the eastern subduction margin (i.e., Mayanmer-Andaman-Sumatra) of India analyzing earthquake dataset with magnitude mb ≥ 4.5 taken from the Harvard Centroid Moment Tensor (CMT) catalogue for the period starting from January 01, 1976 to December 09, 2009. The dataset was divided into two categories: pre- and post-events based on the occurrence of 26 December 2004 off Sumatra mega-event (Mw = 9.3). The study area between Myanmar and Sumatra was divided into 12 sectors based on plate obliquity. Analysis shows that area near Sumatra record highest seismicity concentration, and area past the north Andaman has least concentration, preceding the 2004 mega-event, and further increases marginally towards north. Instead, following the mega-event, concentration though decreases towards north, phenomenally reduces past the sector 7 (near the central part of the arc). The seismic moment energy release decreases more than two orders of magnitude past the sector 7 towards north during post-seismic deformation phase. It is, thus, may be inferred that stress energy was mainly confined between Sumatra and Andaman after the 2004 event. These observations are clearly accounted for tectonic subdivision of the margin into northern and southern near transition zone around the central part of the arc. It was also appreciated in the literature that the transition zone apparently countered spreading motion of the Andaman Sea in the back-arc area. It was furthermore reported that the 2004 off Sumatra mega-event rupture did not move further towards north past the North Andaman area. It is thus, may be proposed that the two arcs along this subduction margin are tectonically playing differently behind the generation of moderate earthquakes along this margin.

3 illus, 1 table, 46 ref

006431   Jana P K;Sarkar D;Saha D K;Midya S K (Chemistry Dep, Government College of Education, Banipur, North-24, Parganas-743 233, Email: pkjjngl@yahoo.co.in) : Effect of cloud occurrences on tropospheric ozone over, Alipore (22.52°N, 88.33°E), India. J Earth Syst Sci 2012, 121(3), 711-22.

Presents the nature of annual cycles of tropospheric ozone, cloud occurrences, NO₂, rainfall, SO₂, SPM, CO, non-methane hydrocarbon and surface solar radiation for the period October 2004 to June 2009 over Alipore (22.52°N, 88.33°E), India. Annual cycle of low-level cloud occurrences depicts that the low-level cloud over Alipore had been noticed to occur for many days and nights, particularly from June to September. The low-level cloud occurrences were found in winter months and post-monsoon period. The effect of cloud occurrences on tropospheric ozone concentration has been critically analysed and explained. It has been observed that the concentration of ozone is oscillatory with cloud occurrences and has a slight linear decreasing trend with the increase of cloud occurrences and vice versa. The concentration of tropospheric ozone attained higher value at moderate cloud occurrences and comparatively lower value at both of the lower and higher cloud occurrences. The related possible chemical and physical explanation for role of cloud occurrences on tropospheric ozone has been offered.

6 illus, 39 ref

006430   Jalal P;Ghosh S K (Geology Dep, H.N.B. Garhwal Univ, Srinagar-246 174, Email: jalal.poonam@gmail.com) : Provenance of the Late Neogene Siwalik Sandstone, Kumaun Himalayan foreland basin: constraints from the metamorphic rank and index of detrital rock fragments. J Earth Syst Sci 2012, 121(3), 781-92.

Understanding about lithology, tectonics and unroofing history of provenance is mostly drawn from the compositional and textural parameters of the detrital fragments. We here use different metamorphic ranks (Rm) and metamorphic index (MI) values of rock fragments present in Late Neogene Siwalik sandstone of the Ramganga sub-basin to infer the provenance history. The study indicates maximum contribution from metamorphic ranks 1 and 2 (Rml and Rm2; meta-sedimentary and very low grade metamorphic rocks) and minimum from metamorphic rank 4 (Rm4; high metamorphic grade rocks). The metamorphic index (MI) values range from 118 to 224, with an average of 186. The meta-sedimentary and very low-grade metamorphic rock fragments are derived from the Lesser Himalayan domain. The medium-to-high grade metamorphic fragments are derived from the Lesser Himalayan Crystalline bodies. The abundance of Rm2 and Rm3 detrital modes suggest the exhumation of crystalline bodies of the Ramgarh and Almora most likely occurred prior to 7 Ma and subsequently the source area shifted and resulted abundant supply of Rm1 fragments due to the upliftment along Main Boundary Thrust around 5.55 Ma.

5 illus, 4 tables, 53 ref

006429   He L B;He W;Qin J H;Yang P;Zhong B;Niu F (Mechanics and Acoustics Div, National Institute of Metrology, Beijing, China, Email: helb1998@sina.com) : Reference infrasound source with low distortion based on laser pistonphone technology. MAPAN 2012, 27(4), 213-8.

For safety protection from infrasound and its metrology, a reference infrasound source was developed on the basis of the laser pistonphone technique. The electromagnetic vibrator was made based on the technology of air bearings and a displacement feedback system. The air bearings reduce the damping of the vibrator, and the displacement feedback system could effectively control the distortion of the pistonphone. Through the displacement of the piston measured by a laser interferometer, the sound pressure could be calculated. In the meantime, the sound pressure was measured by a LS1P microphone with the reciprocity calibration results. The test results show that the difference between the measured pressure and the calculated one is no more than 0.01 dB from 5 to 20 Hz and the total distortion of the sound pressure at 124.0 dB is less than 0.7% from 1 to 20 Hz.

6 illus, 3 tables, 9 ref

006428   Gupta G;Erram V C;Suyash Kumar (NO, Indian Institute of Geomagnetism, Kalamboli Highway, Navi Mumbai-410 218, Email: ggupta@iigs.iigm.res.in) : Temporal geoelectric behaviour of dyke aquifers in northern Deccan volcanic province, India. J Earth Syst Sci 2012, 121(3), 723-32.

Vertical electrical resistivity soundings (VES) were carried out over four major dykes of Nandurbar district in the northern Deccan Volcanic Province (DVP) of Maharashtra to investigate the subsurface geological conditions, with an aim of identifying zones with groundwater resource potential. Dykes can act as pathways or barrier to the groundwater flow depending upon the intensity of fracturing in the dyke rock. Whether the dykes act as water conduits or as barriers depends on their structure, location and orientation with respect to the groundwater flow. The Nandurbar district is known for occurrence of dykes and dyke swarms. A total of 33 dykes were demarcated in the study region and four major dykes (D4, D5, D6, and D7) from these were chosen for detailed VES studies. Data were acquired over these four dykes during pre-monsoon and post-monsoon periods to observe the seasonal variation in groundwater movement. These studies revealed changes in field characters, their attitudes, thickness and structure of the dykes. Longitudinal geoelectrical sections along these dykes demonstrated carrier as well as barrier stretches which identified potential aquifers up to depths of 25-30 m below which hard and compact rock exists. These studies also indicated that dykes with sufficient width, length and favourable hydrogeological structure form potential aquifers for the occurrence and movement of groundwater in the study area.

7 illus, 1 table, 22 ref

006427   Guleria R P;Kuniyal J C;sharma N L;Dhyani P P (NO, G.B. Pant Institute of Himalayan Environment and Development, Himachal Unit, Mohal-Kullu-175 126, Email: jckuniyal@gmail.com) : Seasonal variability ion aerosol optical and physical characteristics estimated using the application of the angstrom formula over Mohal in the Northwestern Himalaya, India. J Earth Syst Sci 2012, 121(3), 697-710.

Investigations of aerosol optical and physical characteristics using the application of Angstrom formula and second order polynomial fit were carried out from April 2006 to March 2009 at Mohal in the Kullu valley. The measurements of spectral aerosol optical depths (AODs) were conducted using multi-wavelength radiometer (MWR). The AOD at 0.5 μm wavelength on daily basis (mean ± standard deviation) for the entire three-year study period is obtained as 0.24 ± 0:08. Seasonal variations show the highest AOD at 0.5 μm wavelength with <126> 0.34 ± 0.08 during pre-monsoon (April-July), followed by 0.26 ± 0.08 during monsoon (August-September), 0.21 ± 0.05 during post-monsoon (October-November) and <126> 0.20 ± 0.07 during winter (December-March). The seasonal values indicate that the AOD at 0.5 μm wavelength is decreasing from pre-monsoon to winter with a notable reduction around 41%. The Angstrom parameters using least square method is not found appropriate for size distribution particularly when coarse mode aerosols dominate. The coefficients of second order polynomial fit are more appropriate for the discrimination of aerosol size or irrespective to the dominance of either of the aerosols size. The difference in coefficient of polynomial fit is used to get confirmation on the dominant mode during different seasons. Study reveals that about 93%, 72% and 59% of AOD spectra are dominated by a wide range of fine mode fractions or mixture of modes during post-monsoon, winter and monsoon, respectively. On the other hand, during pre-monsoon, 72% of AOD spectra are found to be dominated by coarse mode aerosols.

12 illus, 1 table, 38 ref

006426   Ghosh S;Dutta S (Civil Engineering Dep, Indian Institute of Technology Guwahati, Guwahati-781 039, Email: subashisa@iitg.ac.in) : Impact of climate change on flood characteristics in Brahmaputra basin using a macro-scale distributed hydrological model. J Earth Syst Sci 2012, 121(3), 637-57.

Being the highest specific discharge river system in the world, the Brahmaputra river experiences a number of long-duration flood waves during the monsoon season annually. In order to assess the flood characteristics at the basin and tributary scales, a physically based macro-scale distributed hydrological model (DHM) has been calibrated and validated for 9 wet years. The model performance has been evaluated in terms of prediction of the flood characteristics such as peak discharge, flood duration, arrival time of flood wave, timing of the peak flow and number of flood waves per season. Future changes in the flood wave characteristics of the basin have been evaluated using the validated model with bias-corrected future-projected meteorological scenario from a regional climate model (RCM). Likelihood analysis of the simulated flow time series reveals that significant increase in both peak discharge and flood duration is expected for both the pre-monsoonal and monsoonal seasons in the basin, but the number of flood waves per season would be reduced. Under the projected climate change scenario, it is expected that there will be more catastrophic floods in the basin.

17 illus, 5 tables, 43 ref

006425   Erol B (Geomatics Engineering Dp, Civil Engineering Faculty, Istanbul Technical Univ, Maslak 34469, Istanbul, Turkey, Email: bihter@itu.edu.tr) : Spectral evaluation of earth geopotential models and an experiment on its regional improvement for Geoid modelling. J Earth Syst Sci 2012, 121(3), 823-35.

As the number of Earth geopotential models (EGM) grows with the increasing number of data collected by dedicated satellite gravity missions, CHAMP, GRACE and GOCE, measuring the differences among the models and monitoring the improvements in gravity field recovery are required. This study assesses the performance of recent EGMs derived from CHAMP, GRACE, and other data in comparison to the earlier two models in Turkish territory. Also the improvement capacities of these EGMs using local terrestrial data are inspected with two different approaches. In the first approach, the spherical harmonic coefficients of EGMs are modified depending on the local gravity data. In the second part, the original EGMs with their maximum harmonic expansions are employed in Remove Compute Restore algorithm for high resolution local geoid modelling. The assessment results with the local terrestrial data exhibited large disagreements among the models in Turkey. The outputs from regional improvements of EGMs using the gravity observations clarified the important role of the ground truth data contribution in geopotential models. The validations of the computed high resolution geoids rely on the EGMs at the GNSS/levelling networks, having 451 and 309 benchmarks, provided an absolute accuracy by means of standard deviations of the geoid height differences around 20 cm. These results from the final stage of the case study provide a comparison among the EGMs by means of their fit to the local gravity field.

9 illus, 5 tables, 45 ref

006424   Dev S V;Radhakrishna M;Shyam Chand; Subrahmanyam C (Marine Geology and Geophysics Dep, Cochin Science and Technology Univ, Cochin-682 016, Email: mradhakrishna@iitb.ac.in) : Gravity anomalies, crustal structure and rift tectonics at the Konkan and Kerala basins, western continental margin of India. J Earth Syst Sci 2012, 121(3), 813-22.

Litho-stratigraphic variation of sedimentary units constructed from seismic sections and gravity anomaly in the Konkan and Kerala basins of the western continental margin of India (WCMI) have been used to model processes such as lithospheric rifting mechanism, its strength, and evolution of flank uplift topography that led to the present-day Western Ghats escarpment. Based on the process-oriented approach, two lithospheric models (necking and magmatic underplating) of evolution of the margin were tested. Both, necking and underplating models suggest an effective elastic thickness (Te) of 5 km and 10 km along Konkan and Kerala basins, respectively and a deep level of necking at 20 km at both basins. Model study suggests that the necking model better explains the observed gravity anomalies in the southern part of the WCMI. A synthesis of these results along with the previously published elastic thickness estimates along the WCMI suggests that a low-to-intermediate strength lithosphere and a deeper level of necking explains the observed flank-uplift topography of the Western Ghats. Process-oriented gravity modelling further suggests that the lateral variations in the lithospheric strength, though not very significant, exist from north to south within a distance of 600 km in the Konkan and Kerala basins along the WCMI at the time of rifting. A comparison with previous Te estimates from coherence analysis along the WCMI indicates that the lithospheric strength did not change appreciably since the time of rifting and it is low both onshore and offshore having a range of 5-15 km.

4 illus, 1 table, 45 ref

006423   Chatterjee A;Shankar D;Shenoi S S C;Reddy G V;Michael G S;Ravichandran M;Gopalkrishna V V;Rama Rao E P;Udaya Bhaskar T V S;Sanjeevan V N (NO, National Institute of Oceanography (Council of Scientific and Industri, Dona Paula, Goa-403 004, Email: chatterjeea.ocean@gmail.com) : New atlas of temperature and salinity for the North Indian Ocean. J Earth Syst Sci 2012, 121(3), 559-93.

The most used temperature and salinity climatology for the world ocean, including the Indian Ocean, is the World Ocean Atlas (WOA). (Antonov et al 2006, 2010; Locarnini et al 2006, 2010) because of the vast amount of data used in its preparation. The WOA climatology does not, however, include all the available hydrographic data from the Indian Exclusive Economic Zone (EEZ), leading to the potential for improvement if the data from this region are included to prepare a new climatology. We use all the data that went into the preparation of the WOA (Antonov et al 2010; Locarnini et al - 2010), but add considerable data from Indian sources, to prepare new annual, seasonal, and monthly climatologies of temperature and salinity for the Indian Ocean. The addition of data improves the climatology considerably in the Indian EEZ, the differences between the new North Indian Ocean Atlas (NIOA) and WOA being most significant in the Bay of Bengal, where the patchiness seen in WOA, an artifact of the sparsity of data, was eliminated in NIOA. The significance of the new climatology is that it presents a more stable climatological value for the temperature and salinity fields in. the Indian EEZ.

2 illus, 7 tables, 63 ref

005408   Sujeet Kumar;Mishra P K;Singh N L;Singh K K; Srivastava P (Environmental Science Dep, Banaras Hindu University, Varanasi, Uttar Pradesh) : Water quality of river Varuna in Varanasi city, Uttar Pradesh, India. Asian J biochem pharm Res 2012, 2(2), 231-40.

Study was made to determine the surface water quality status of river Varuna in Varanasi City. Water quality assessment of river Varuna is done on the basis of 15 parameters at 32 different sampling sites between Kotwa (upstream of Varanasi City) and Aadikeshav Ghat (Ganga- Varuna Sangam). Appreciable deterioration in water quality of the river can be observed from upstream of Varanasi City to Ganga Varuna Sangam. Alarming depletion of dissolved oxygen level in river water is an indication of disposal of untreated sewage and industrial effluent. To assess the quality of water of river Varuna, each parameter was compared with the standard desirable limit of that parameters in surface water as prescribed by IS:2296.

11 ref

005407   Sivamadhavi V;Selvaraj R S (Physics Dep, Bharathi Women's College, Chennai, Tamil Nadu, Email: siva madhavi03@yahoo.com) : Prediction of monthly mean daily global solar radiation using Artificial Neural Network. J Earth Syst Sci 2012, 121(6), 1501-10.

In this study, a multilayer feed forward (MLFF) neural network based on back propagation algorithm was developed, trained, and tested to predict monthly mean daily global radiation in Tamil Nadu, India. Various geographical, solar and meteorological parameters of three different locations with diverse climatic conditions were used as input parameters. Out of 565 available data, 530 were used for training and the rest were used for testing the artificial neural network (ANN). A 3-layer and a 4-layer MLFF networks were developed and the performance of the developed models was evaluated based on mean bias error, mean absolute percentage error, root mean squared error and Student's t-test. The 3-layer MLFF network developed in this study did not give uniform results for the three chosen locations. Hence, a 4-layer MLFF network was developed and the average value of the mean absolute percentage error was found to be 5.47%. Values of global radiation obtained using the model were in excellent agreement with measured values. Results of this study show that the designed ANN model can be used to estimate monthly mean daily global radiation of any place in Tamil Nadu where measured global radiation data are not available.

9 illus, 3 tables, 23 ref

005406   Singh K;Chand P (Environmental Science Dep, Maharishi Dayanand University, Rohtak, Haryana 124 001, Email: pritamiirs@gmail.com) : Above-ground tree outside forest (TOF) phytomass and carbon estimation in the semi-arid region of Southern Haryana: A synthesis approach of remote sensing and field data. J Earth Syst Sci 2012, 121(6), 1469-82.

Trees outside forest (TOF) play an important role in global carbon cycling, since they are large pools of carbon as well as potential carbon sinks and sources to the atmosphere. In view of the importance of biomass estimates in the global carbon (C) cycle, the present study demonstrates the potential of the standwise tree outside forest inventory data and finer spatial resolution of IRS-P6 LISS-IV satellite data to classify TOF, to estimate above-ground TOF phytomass and the carbon content of TOF in a semiarid region of the southern Haryana, India. The study reports that above-ground TOF phytomass varied from 1.26 tons/ha in the scattered trees in the rural/urban area to 91.5 tons/ha in the dense linear TOF along the canal. The total above-ground TOF phytomass and carbon content was calculated as 367.04 and 174.34 tons/ha, respectively in the study area. The study results conclude that the classification of TOF and estimation of phytomass and carbon content in TOF can be successfully achieved through the combined approach of Remote Sensing and GIS based spatial technique with the supplement of field data. The present approach will help to find out the potential carbon sequestration zone in the semi-arid region of southern Haryana, India.

7 illus, 4 tables, 28 ref

005405   Shah A A;Bell T H (School of Earth and Environmental Sciences, James Cook University, Townsville, Qld 4811, Australia, Email: afroz@ntu.edu.sg) : Ninety million years of orogenesis, 250 million years of quiescence and further orogenesis with no change in PT: Significance for the role of deformation in porphyroblast growth. J Earth Syst Sci 2012, 121(6), 1365-99.

In situ dating of monazite grains preserved as inclusions within foliations defining FIAs (foliation inflection/intersection axes preserved within porphyroblasts) contained within garnet, staurolite, andalusite and cordierite porphyroblasts provides a chronology of ages that matches the FIA succession for the Big Thompson region of the northern Colorado Rocky Mountains. FIA sets 1, 2 and 3 trending NE-SW, E-W and SE-NW were formed at 1760.5 ± 9.7, 1719.7 ± 6.4 and 1674 ± 11 Ma, respectively. For three samples where garnet first grew during just one of each of these FIAs, the intersection of Ca, Mg, and Fe isopleths in their cores indicate that these rocks never got above 4 kbars throughout the Colorado Orogeny. Furthermore, they remained around approximately the same depth for ~250 million years to the onset of the younger Berthoud Orogeny at 1415 ± 16 Ma when the pressure decreased slightly as porphyroblasts formed with inclusion trails preserving FIA set 4 trending NNE-SSW. No porphyroblast growth occurred during the intervening ~250 million years of quiescence, even though the PT did not change over this period. This confirms microstructural evidence gathered over the past 25 years that crenulation deformation at the scale of a porphyroblast is required for reactions to re-initiate and enable further growth.

17 illus, 7 tables, 53 ref

005404   Saha A;Lijesh S;Mandal P (NO, National Geophysical Research Institute (Council of Scientific and Ind, Hyderabad-500 606, Email: prantik@ngri.res.in) : Simultaneous estimation of earthquake source parameters and crustal Q value from broadband data of selected aftershocks of the 2001 M_w 7.7 Bhuj earthquake. J Earth Syst Sci 2012, 121(6), 1421-40.

This paper presents the simultaneous estimation of source parameters and crustal Q values for small to moderate-size aftershocks (M_w 2.1-5.1) of the M_w 7.7 2001 Bhuj earthquake. The horizontal-component S-waves of 144 well located earthquakes (2001-2010) recorded at 3-10 broadband seismograph sites in the Kachchh Seismic Zone, Gujarat, India are analyzed, and their seismic corner frequencies, long-period spectral levels and crustal Q values are simultaneously estimated by inverting the horizontal component of the S-wave displacement spectrum using the Levenberg-Marquardt nonlinear inversion technique, wherein the inversion scheme is formulated based on the ω-square source spectral model. The static stress drops (Δσ) are then calculated from the corner frequency and seismic moment. The estimated source parameters suggest that the seismic moment (M₀) and source radius (r) of aftershocks are varying from 1.12 x 1012 to 4.00 x 1016 N-m and 132.57 to 513.20 m, respectively. Whereas, estimated stress drops (Δσ) and multiplicative factor (E_mo) values range from 0.01 to 20.0 MPa and 1.05 to 3.39, respectively. The corner frequencies are found to be ranging from 2.36 to 8.76 Hz. The crustal S-wave quality factor varies from 256 to 1882 with an average of 840 for the Kachchh region, which agrees well with the crustal Q value of the seismically active New Madrid region, USA. Our estimated stress drop values are quite large compared to the other similar size Indian intraplate earthquakes, which can be attributed to the presence of crustal mafic intrusives and aqueous fluids in the lower crust as revealed by the earlier tomographic study of the region.

9 illus, 3 tables, 47 ref

005403   Mahadevaswamy G;Nagaraju D (Studies in Geology Dep, Manasagangotri University of Mysore, Mysore-570 006) : Determination of specific yield in Kuderu micro water shed of Chamarajanagar and Nanjanagud taluks, Karnataka. J Ecotoxic envir Monit 2011, 21(3-4), 341-5.

An attempt has bean made to compute the specific yield of water table aquifer of granitic formation in Kuderu micro watershed having an area of 58 sq km. of Chamarajanagar and Mysore district, Karnataka during February to March-2009 using Water Balance Equation. Total ground water extracted in the water shed has bean estimated as 0.00930 mcm. Adhoc norms for recharge due to ground water irrigation has bean considered based on the type of crop (paddy or non paddy) and depth of water table below ground level, which worked out as 0.00232 m.cm. (25% of total volume of water extracted in the area). The volume of aquifer de watered was calculated by multiplying the area of water shed (1.75 sq.km.) and the average water level fluctuation (0.72 m.), which is 1.26 mcm. The Specific Yield of phreatic aquifer in granitic terrain of micro watershed was calculated using Water Balance Equation and the value of 0.55% was arrived as per the studies.

1 illus, 2 tables, 5 ref

005402   Jana P K;Saha D K;Sarkah D (Chemistry Dep, Institute of Education (P. G) for Women, Chandernagore, Hooghly 712 138, West Bengal, Email: pkjjngl@yahoo.co.in) : Yearly variation and annual cycle of total column ozone over New Delhi (29°N, 77°E), India and Halley Bay (76°S, 27°W), British Antarctic Survey Station and its effect on night airglow intensity of OH(8, 3) for the period 1979-2005. J Earth Syst Sci 2012, 121(6), 1527-41.

A critical analysis made on the long-term monthly, seasonal, yearly variation and annual cycle of total column ozone (TCO) concentration at New Delhi (29°N, 77°E), India and Halley Bay (76°S, 27°W), a British Antarctic Service Station reveals more decline in yearly mean ozone concentration at Halley Bay than at New Delhi from 1979 to 2005. The nature of variations of monthly mean TCO during the months of August and September was the most identical with that of yearly mean ozone values at New Delhi and Halley Bay, respectively, for the same period. Annual cycles of TCO over these stations are completely different for the above period. The effect of O₃ depletion on night airglow emission of OH(8, 3) line at New Delhi and Halley Bay has been studied. Calculations based on chemical kinetics show that the airglow intensity of OH(8, 3) has also been affected due to the depletion of O₃ concentration. The yearly variations and annual cycle of intensities of OH(8, 3) line for the above two stations are depicted and compared. It has been shown that the rate of decrease of intensity of OH(8, 3) line was comparatively more at Halley Bay due to dramatic decrease of Antarctic O₃ concentration.

9 illus, 5 tables, 57 ref

005401   Huang Z;Yuan W;Wang C;Liu X (State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, No. 29, Xueyuan Road, Beijing 100083, People's Republic of China, Email: ywm010@yahoo.com) : Metallogenic epoch of the Jiapigou gold belt, Jilin Province, China: Constrains from rare earth element, fluid inclusion geochemistry and geochronology. J Earth Syst Sci 2012, 121(6), 1401-20.

Jiapigou gold belt is located on the northern margin of the North China Craton, and is one of the most important gold-mining and production regions in the circum-Pacific metallogenic zone. Research has been conducted in this area since the 1960s, however, the timing of the gold mineralisation is still unresolved, and an ideal metallogenic model has not been well established. To address these questions, a systematic geological, geochemical and geochronological investigation was conducted. The study revealed that (i) the gold-bearing quartz veins can be divided into two groups, earlier and later gold-bearing quartz veins according to their occurrence and the geochemical characteristics, (ii) the geochemical characteristics of the ore bodies, while similar to granite, are clearly different from the altered rock, and (iii) the geochemical characteristics of the later gold-bearing quartz veins have more similarity to the altered rock than the earlier gold-bearing quartz veins do. Therefore, we conclude that two independent stages of metallogenesis within the Jiapigou gold deposit area are related to magmatic activity in the Palaeoproterozoic and the Yanshanian stage of the Mesozoic, that the ore-forming fluids are mainly of magmatic origin, and that magma contamination by the altered rock was stronger in the Mesozoic. Zircon LA-ICP-MS U-Pb data show that the age of the Palaeoproterozoic granite is <126>2426.0 Ma and that of the Mesozoic granite is <126>166.2 Ma; these ages can be interpreted as the maximum ages of the two periods of gold mineralisation. In addition to investigating the geotectonic and regional structure of the Jiapigou gold belt, this study also proposes that the WNW-trending zone of gold mineralization is a result of a magmatic event within the basement in the early Palaeoproterozoic, and that largescale sinistral strike-slip displacements of the Huifahe and Liangjiang Faults in the late Middle Triassic (Yanshanian epoch) controlled the later tectono-magmatic event and the NNE-ENE-trending zone of gold mineralisation.

13 illus, 3 tables, 58 ref

005400   Ghosh S;Bhattacharya K (Post-Graduate Geography Dep, The University of Burdwan, Burdwan-713 104, West Bengal, Email: sandipanghosh19@gmail.com) : Multivariate erosion risk assessment of lateritic badlands of Birbhum (West Bengal, India). J Earth Syst Sci 2012, 121(6), 1441-54.

Each geomorphic hazard involves a degree of risk which incorporates quantification of the probability that a hazard will be harmful. At present, the categorization of sub-watersheds into erosion risk is considered as the fundamental step to conserve the soil loss. Development of badlands over the laterites of Birbhum district is an indicative of excessive soil loss in the monsoonal wet-dry type of climate. Slope erosion and channel erosion have generated huge amount of sediment from the small watersheds during intense monsoonal rainfall (June-September). The adjoining areas of Rampurhat I Block, Birbhum (West Bengal) and Shikaripara Block, Dumka (Jharkhand) have lost the lateritic soil cover at a rate of 20-40 ton/ha/year (Sarkar et al. 2005). In order to estimate the progressive removal of soil particles from the gully-catchments of the above-mentioned area, different morphometric parameters, soil parameters, hydrologic parameters and empirical models are employed. Side by side, the study is carried out to categorize the gully-catchments into different magnitude of erosion risk using several multivariate statistical techniques.

10 illus, 6 tables, 48 ref

005399   Ghosh N;Madhuri Rishi;Renu Lata (Environment and Vocational Studies Dep, Panjab Universaity, Chandigarh-160 014, Email: manighsh@yahoo.com) : Hydrochemistry and groundwater quality in Ghanaur block of district Patiala, Punjab, India. Asian J Microbiol Biotechnol envir Sci 2011, 13(4), 715-22.

The paper reports groundwater quality in Ghanaur Block of district Patiala, Punjab, India. It was observed the natural quality of groundwater is undoubtedly the result of number of physical, chemical and biological reactions as well as processes occurring to some degrees in the unsaturated as well as in the saturated zones. Groundwater is generally alkaline in nature with pH ranging between 7.6 and 9.2 with an average of 8.12. The EC of groundwater ranged from 650 μS/cm to above 1840 μS/ cm with a mean of 1245 μS/cm. Among cations, sodium was the most dominant cation followed by Ca & Mg. Among the anions, SO₄ and Cl ion were found to be dominating in the water. From the above analysis, it is concluded that the groundwater in Ghanaur block of district Patiala is in general is suitable for domestic and agricultural purposes

10 illus, 2 tables, 11 ref

005398   Ghoppage R N;Singh D;Singh R P;Mukherjee G K; Vohat P;Singh A K (Medium Frequency Radar, Indian Institute of Geomagnetism, Shivaji University Campus, Kolhapur 416 00, Email: rupesh_ghodpage@rediffmail.com) : Tidal and gravity waves study from the airglow measurements at Kolhapur (India). J Earth Syst Sci 2012, 121(6), 1511-25.

Simultaneous photometric measurements of the OI 557.7 nm and OH (7, 2) band from a low latitude station, Kolhapur (16.8°N, 74.2°E) during the period 2004-2007 are analyzed to study the dominant waves present in the 80-100 km altitude region of the atmosphere. The nocturnal intensity variations of different airglow emissions are observed using scanning temperature controlled filter photometers. Waves having period lying between 2 and 12 hours have been recorded. Some of these waves having subharmonic tidal oscillation periods 4, 6, 8 and 12 hours propagate upward with velocity lying in the range 1.6-11.3 m/s and the vertical wave length lying between 28.6 and 163 kms. The other waves may be the upward propagating gravity waves or waves resulting from the interaction of inter-mode tidal oscillations, interaction of tidal waves with planetary waves and gravity waves. Some times, the second harmonic wave has higher vertical velocity than the corresponding fundamental wave. Application of these waves in studying the thermal structure of the region is discussed.

12 illus, 1 table, 69 ref

005397   Das R K;Datt P;Acharya A (Snow and Avalanche Study Establishment (SASE), , Sector-37A, Chandigarh 160 036, Email: rk.das@sase.drdo.in) : Assessment of the FlowCapt acoustic sensor for measuring snowdrift in the Indian Himalayas. J Earth Syst Sci 2012, 121(6), 1483-91.

Wind caused snow drifting plays a dominant role in the redistribution of snow mass that restructures a snowpack. Strong wind activity at the mountain tops results in uneven distribution of snow with erosion on windward side and deposition on leeward areas. Such snowdrift events are responsible for the formation of cornices, increase in the loading of avalanche release zones on the leeward side and consequent increase in the level of avalanche hazard. In this paper, aithors present the results of snowdrift measurement using an acoustic snow-drift meter, the FlowCapt, built by IAV Engineering, which was used during winter seasons of 2007-2010 at a field research station of Snow and Avalanche Study Establishment (SASE) in the western Himalayas. The aim of the study was to evaluate the suitability of the instrument in measuring snowdrift in the Himalayan weather conditions. Results proved the utility of the instrument as a useful tool to study drifting snow in remote areas. However, in the absence of conventional snow gauges for validation, the quality of the absolute snow flux data could not be ascertained.

8 illus, 3 tables, 24 ref

005396   Comanescu L;Nedelea A (Geomorphology-Pedology T-Geomatics Dep, Bucharest University, 010041, No. 1, N. Balcescu Avenue, Bucharest, Romania, Email: lauracomanescu@yahoo.com) : Assessment of geodiversity - a premise for declaring the geopark Buzaului County (Romania). J Earth Syst Sci 2012, 121(6), 1493-1506.

Geopark Buz?aului County does not belong to the Geoparks European Network, as there are numerous governmental, legislative and scientific initiatives in this respect. The geopark is situated in the central-south-eastern part of Romania (in Buzau county) and it has a special potential of geological, geomorphological, biogeographical and anthropic nature, a potential which has to be developed and brought into value. The idea of creating a geopark in this area is relatively recent and it was realized by a series of actions carried on by local authorities in partnership with several institutions, a partnership within which it was accomplished the proposal of a general development framework of the geopark, as well as the launching of a promotion campaign. The scope of this work is to evaluate the geodiversity existing in this space as an important starting point in declaring it as a European geopark, being known that it represents a real "open air museum". The high values of geodiversity and biodiversity represent special strong points in this respect. The method we used was taken from the specialised literature, suffering a series of adjustments to the specifics of the studied area. In the present format, the method is applied for the first time in the Geography literature, so the values obtained cannot be compared with those obtained by other calculation formulas. Thus, values between 0.20 and 1.91 which resulted cover the entire scale of variables proposed.

4 illus, 3 tables, 21 ref

005395   Chandra S;Nagaiah E;Reddy D V;Ananda Rao V; Ahmed S (NO, CSIR - National Geophysical Research Institute, Uppal Road, Hyderabad-500 007, Email: schandra75@gmail.com) : Exploring deep potential aquifer in water scarce crystalline rocks. J Earth Syst Sci 2012, 121(6), 1455-68.

Characterization of the shear zone with pole-pole electrical resistivity tomography (ERT) was carried out to explore deep groundwater potential zone in a water scarce granitic area. As existing field conditions does not always allow to plant the remote electrodes at sufficiently far of distance, the effect of insufficient distance of remote electrodes on apparent resistivity measurement was studied and shown that the transverse pole-pole array affects less compared to the collinear pole-pole array. Correction factor have been computed for transverse pole-pole array for various positions of the remote electrodes. The above results helped in exploring deep aquifer site, where a 270 m deep well was drilled. Temporal hydro-chemical samples collected during the pumping indicated the hydraulic connectivity between the demarcated groundwater potential fractures. Incorporating all the information derived from different investigations, a subsurface model was synthetically simulated and generated 2D electrical resistivity response for different arrays and compared with the field responses to further validate the geoelectrical response of deep aquifer set-up associated with lineament.

9 illus, 1 table, 40 ref

005394   Bharani P L;Madesh P;Vijayakumar S;Manjunath S (Earth Science Dep, University of Mysore, Myssore-570 066) : Authigenic quatz overgrowth and tectono-environmental sedimentary formations in the Western part of the Palnad basin, Andhra Pradesh. J Ecotoxic envir Monit 2012, 22(1-2), 187-95.

The detrital quartz showing well developed authigenic quartz have been reported from the quartzarenites of the Kurnool group. Petrographic studies reveal medium to line grained texture and the grains cemented by silica mostly as secondary enlargements. The detrital quartz showing well developed secondary enlargements not only indicates pressure solution but also indicates that they have developed during anadiagenesis. The lithologic character of sediments. geometry and sedimentary characters belonging to Palnad basin have been taken to interpreting the tectono-environment classification of sedimentary fonnation,0fthe Palnad basin. The Banganpalli qual1izitcs were deposited in the littoral to infra-littoral environment stable shelf conditions. The Narji limestones deposited in infra-littoral to neritic environment. Due to uplift the environment changed to infra-littoral and quiet water environment. The Paniam quartzites were deposited in the littoral to infra-littoral environment under stable shelf conditions with minor tectonic instability in certain areas. The Kundair limestones and shales were deposited in neritic zones under reducing environment on stable shelf conditions.

4 illus, 2 tables, 12 ref

004333   Tailor G S;Chandel C P S (Chemistry Dep, Rajasthan Univ, Jaipur, Email: chandelcps2rediffmail.com) : Hydrochemistry of Malpura tehsil (Tonk, Rajasthan), India by analysis of various ground water quality parameters. Pollut Res 2011, 30(2), 195-200.

Ground water, being a fragile and important source of drinking water, must therefore be carefully managed to maintain its purity within standard limits. In order to evaluate the major suitability of water for drinking, irrigation and domestic use, the chemical characteristics of groundwater in Malpura Tehsil (Tonk district, Rajasthan) have been investigated and evaluated. Water samples from hand pumps, open wells and bore wells were collected during mansoon session2009 and analyzed for major anions (HCO₃, Cl^-, P, SO₄^2-, NO₃, CO₃^2-) and major cations (Ca²⁺, Na⁺, Mg²⁺, K⁺) besides physical and chemical parameters (pH, electrical conductivity, total dissolved solids and total hardness). To understand the water quality and utilitarian aspects of ground water, chemical indices like SAR, RSC, %Na, Piper trilinear diagram and US salinity laboratory hazard diagram were calculated based on the analytical results. According to EC and SAR calculation the most dominant classes C4S2, C4S3, C3S1, C3S2, C3S3 and C2S1 were found. The water that predominated in the study area is Na⁺- K⁺- C^- - SO₄^2- typed, based on hydro chemical facies.

2 illus, 3 tables, 20 ref

004332   Shukla R;Khare D (Water Resources Development and Management Dep, Indian Institute of Technology, Roorkee, Uttarakhand, Email: srituraj11@gmail.com) : Land use/land cover change detection of indira sagar canal command area using integrated remote sensing and GIS tools. Res Rev : J Space Sci Technol 2013, 2(2), 27-35.

In recent years, the significance of spatial data technologies, especially the application of remotely sensed data and geographical information systems (GIS), has been widely used. Land cover/land use is one of the influencing factors when it comes to catchment runoff. Hence, it is necessary to carefully consider both spectral and spatial characteristics of the sensor and accuracy of representative areas of predefined classes. The current study explores the change in water bodies, mixed plant, grass and shrubs, fallow land, agricultural land, urbanization growth using IRS satellite data for the decade, between 2000 and 2010 over Indira Sagar Canal command area. Supervised classification method is used to classify the urban land use and land cover. GIS is used to prepare different layers belonging to various land uses identified from remotely sensed data. The investigation outcome shows intense decrease in fallow land from 1846.64 km² in 2000 to 1031.48 km² in 2010. In the period 2000 to 2010, the decadal change was found in green land. Likewise, agriculture land increased from 15 to 18%, grass and shrubs from 18.5 to 19% and mixed plant increased from 7.6 to 12%). This drastic significant result is due to the construction of canal in Indira Sagar Canal command area which changes the whole scenario of the study area.

6 illus, 1 table, 12 ref

004331   Shirahatti M S;Dodaman B M;Kuligod V B; Balakrishnan P;Barkar R D (AICRPDA, Regional Agricultural Research Station, Bijapur-586 101, Email: msshirahatti@gmail.com) : Impact of subsurface drainage system on reclamation of waterlogged area. Envir Ecol 2012, 30(3B), 877-80.

Similar to many irrigation command areas in the country, the Upper Krishna Project (UKP) com-mad area in Karnataka has been affected by the problems of waterlogging and salinity. These problems are on the rise after the introduction of irrigation during 1980s. The farms of the UKP Command Area Development Authority and the Agricultural Research Station (ARS) at Kawadimatti, Gulbarga in district, Karnataka were also among the areas affected by these problems. The investigations revealed that the soils underlain by poorly permeable clay soils, seepage from distributaries and irrigation channels and from the surrounding upland irrigated areas and growing of paddy in the adjoining lands were the main causes of the drainage problem. As a result, there was drastic reduction in crop yields and in some cases the lands became barren and were abandoned. To reclaim the waterlogged area, subsurface drains (SSDs) were laid in an area of about 3.6 ha in a part of the affected lands in the ARS farm, by adopting 60 m spacing during 2000. Composite system of drainage with laterals and collector was adopted. For the laterals, PVC perforated and corrugated pipes of 8 and 10 cm diameter with nylon filter (of 60 mesh) were used. RCC hume non-pressure pipes of 22.5 cm diameter were used as the collector. Due to the drainage works undertaken, the water table lowered from 20 cm during the pre-drainage situation to 60 cm below the ground level. The crop cutting studies revealed that groundnut yield increased to 31q/ha (more than 1.8 times) in the drained area against the yield of 11 q/ha in the un-drained area. The average drain discharges observed in the laterals and the collector were 3 and 3.2 mm during kharif and 2.6 and 2.8 mm during rabi respectively. It was also found that the sediment deposition in the pipe was negligible. The cost of the drainage system was Rs 24,000/ha. The benefit cost ratio was about two and the investment was found to be recoverable in a period of 3-4 years (pay back period).

1 illus, 4 tables, 7 ref

004330   Rajeev Kumar;Chandola V K;Singh R M (Far Engineering Dep, Institute of Agricultural Sciences, Banaras Hindu Univ, Varanasi-221 005, Email: rajeev_kumar1969@rediffmail.com) : Dynamic runoff model for Giridih watershed of Barakar river basin, Jharkhand. Envir Ecol 2012, 30(3B), 900-5.

Rainfall-runoff process, which involves many mechanisms, is highly complicated and dynamic in nature. In the present study, an attempt was made to develop dynamic runoff model, considering present day rainfall and past value of rainfall and runoff as the input variable, to estimate the runoff from a catchment on daily basis. The model was applied on Giridih watershed, a sub-catchment of Barakar river basin, Jharkhand, Comprising an area.of 731.02 km², to test its applicability and capacity to estimate and generate daily runoff data for the catchment. The estimated and generated values of runoff by developed model were found to be in good agreement with the measured values.

4 illus, 19 ref

004329   Pradeep C M;Yasmin;Bhakar S R;Machiwal D; Singh P K (NO, CTAE, Udaipur, Rajasthan, Email: pradeep0393@gmail.com) : Development of rainfall-recharge models for Udaipur district, Rajasthan. Envir Ecol 2012, 30(3B), 892-9.

In the present study, Udaipur district was selected as a study area, which is situated in southern part of the largest and driest state (Rajasthan) of India. It consists of 11 blocks (viz., Badgaon, Bhinder, Dhariawad, Girwa, Gogunda, Jhadol; Kherwara, Kotra. Mavli, Salumber and Sarada). The six models were developed for this study to develop rainfall-recharge models for the 11 blocks of study area. The six models tried were namely linear model, logarithmic model, exponential model and polynomial model of 2, 3 and 4th order. The groundwater recharge estimated by newly developed models and groundwater recharge by water balance method were compared using correlation coefficient, root mean square error, standard error and per cent deviation with observed recharge. Results show that linear model, logarithmic model, exponential model were found to be suitable for all 25 zones. However, considering correlation coefficient, root mean square error, standard error and per cent deviation with observed recharge logarithmic model showed high value of correlation coefficient, less root mean square error, less standard error and less per cent deviation with observed recharge as compared to linear and exponential models. Therefore, it was recommended that logarithmic model was found suitable for Udaipur region.

1 illus, 7 tables, 3 ref

004328   Bhavana C P;Munirajappa R;Surendra H SV; Rathod S (Agricultural Statistics Dep, Applied Mathematics & Computer Science, Agricultural Sciences Univ, GK, Bengaluru-560 065, Email: santoshagriculture@gmail.com) : Modeling of daily rainfall using gamma probability distribution. Envir Ecol 2012, 30(3B), 884-7.

Gamma probability distribution was fitted for 30 years (1980-2010) daily rainfall data of southern dry zone of Karnataka. Southwest monsoon rainfall distributions of this zone are found to abide by gamma probability distribution function which is confirmed on the basis of chi-square tests. The rainfall sequences recorded for the last 30 years from June to September (southwest monsoon) are investigated statistically and gamma distribution parameters are calculated at existing stations of the zone. The shape and scale parameters are then regionalized and hence it becomes possible to find the parameter values at any desired location within the study area. Then the probability of occurrence of ≤50, 50-150. 150-250 and ≥250 mm of rainfall were obtained for the months of June, July, August and September.

2 tables, 5 ref

003395   Zhang H B;Qian H;Li P Y;Wu J H (School of Environmental Science and Engineering, Changan University, Yanta Road, Xi'an, P.R. China, , Email: hbzhang@chd.edu.cn) : Formation mechanism of water chemical compositions in the lower reaches of Dusitu river, China. Asian J Chem 2012, 24(2), 573-8.

The objective of this paper is to find out the factors causing river water chemical compositions changes in the lower reaches of Dusitu river. River water samples and groundwater samples were collected and analyzed for chemical and isotopic indices. The relationships between water chemical characteristics and geological situation, river flow and hydrogeology conditions were discussed in the study. The results show that: (1) the river flow increases firstly and then decreases along flow path, (2) the δ¹⁸O and δD in river water decrease in certain degree with flow growth, but increase significantly with flow decreasing, (3) the TDS change and content change of each component increase along flow direction in the same flow, but more stable than the above parameters, (4) the corresponding hydrochemistry types of river water change from Cl-SO₄-Na to SO₄-Cl-Na influenced strongly by the changes mentioned before. Based on these understanding, we divided the middle and lower Dusitu River into three sub-reaches. This paper discussed the formation mechanisms of river water chemical compositions on every reach by mass balance model, saturation index and isotope fractionation. It is concluded that the formation mechanism on river water chemical composition is in difference each other taken from different reaches in Dusitu river. In its middle reach, the mixing process between river water and groundwater, dissolution of gypsum and halite and the precipitation of calcite play major roles in chemical composition forming process. In the lower river, evaporation, concentration and mixing action are the key factors to impact the formation mechanism, especially evaporation, its proportion obtained about 28.05 % according to the calculated result from isotopic data.

5 illus, 5 tables, 21 ref

003394   Zeng Z;Wang Q;Wang X;Chen S;Yin X;Li Z (Seafloor Hydrothermal Activity Laboratory of the Key Laboratory of Ma, Institute of Oceanography, Chinese Academy of Sciences, Qingdao 266071, China, Email: zgzeng@ms.qdio.ac.cn) : Geochemistry of abyssal peridotites from the super slow-spreading Southwest Indian Ridge near 65°E: Implications for magma source and seawater alteration. J Earth Syst Sci 2012, 121(5), 1317-36.

Geochemical characteristics of abyssal peridotite samples from one dredge station (27°49.74'S, 65°02.14'E, water depth 4473 m) on the super slow-spreading Southwest Indian Ridge (SWIR) near 65°E were investigated. Abyssal peridotites recovered from this site were comprised mainly of lizardite, chlorite, carbonate and magnetite with minor amounts of talc, pyroxene phenocrysts and sparse olivines. Serpentinites exhibit talc veins and major serpentine derived from serpentinization with relict olivine granuloblasts. Olivine grains in serpentinites display exsolution lamellae, indicating the occurrence of talc reduction or decompression during seawater-rock interaction. Pyroxene shows clear cleavage in two directions, with clinopyroxene or orthopyroxene exsolution lamellae. By contrast, bulk rock trace element patterns of serpentinites reveal depletion in most incompatible elements, similarly to the depleted midocean ridge basalt mantle composition, indicating that the SWIR peridotites originated from a depleted mantle source magma and have experienced partial melting. Meanwhile, Rb, Ba, U, Pb, Sr, Li anomalies and the Ce/Pb ratio suggest that these serpentinites have been strongly altered by seawater.

10 illus, 5 tables, 82 ref

003393   Yidana S M;Banoeng Yakubo B;Sakyi P A (Earth Science Dep, University of Ghana, Legon, Accra, Ghana, Email: smyidana@ug.edu.gh) : Identifying key processes in the hydrochemistry of a basin through the combined use of factor and regression models. J Earth Syst Sci 2012, 121(2), 491-507.

Innovative technique of measuring the intensities of major sources of variation in the hydrochemistry of (ground) water in a basin has been developed. This technique, which is based on the combination of R-mode factor and multiple regression analyses, can be used to measure the degrees of influence of the major sources of variation in the hydrochemistry without measuring the concentrations of the entire set of physico-chemical parameters which are often used to characterize water systems. R-mode factor analysis was applied to the data of 13 physico-chemical parameters and 50 samples in order to determine the major sources of variation in the hydrochemistry of some aquifers in the western region of Ghana. In this study, three sources of variation in the hydrochemistry were distinguished: the dissolution of chlorides and sulfates of the major cations, carbonate mineral dissolution, and silicate mineral weathering. Two key parameters were identified with each of the processes and multiple regression models were developed for each process. These models were tested and found to predict these processes quite accurately, and can be applied anywhere within the terrain. This technique can be reliably applied in areas where logistical constraints limit water sampling for whole basin hydrochemical characterization. Q-mode hierarchical cluster analysis (HCA) applied to the data revealed three major groundwater associations distinguished on the basis of the major causes of variation in the hydrochemistry. The three groundwater types represent Na-HCO₃, Ca-HCO₃, and Na-Cl groundwater types. Silicate stability diagrams suggest that all these groundwater types are mainly stable in the kaolinite and montmorillonite fields suggesting moderately restricted flow conditions.

9 illus, 2 tables, 36 ref

003392   Tripathi A;Vijaya;Murthy S;Chakraborty B;Das D K (NO, Birbal Sahni Institute of Palaeobotany, Kolkata, Email: srikanta_murthy22@rediffmail.com) : Stratigraphic status of coal horizon in Tatapani-Ramkola Coalfield, Chhattisgarh, India. J Earth Syst Sci 2012, 121(2), 537-57.

Palynostratigraphic data given here are based on the explored borecores (TRBD-2, TRBD-3 and TROD-1), by Geological Survey of India. The Permian strata worked-out is about 1174.00 m thick and comprises from base to top - Talchir, Barakar and Barren Measures formations. The palynological content enables delimitation of five palynological assemblages. (i) Scheuringipollenites barakarensis, (ii) Faunipollenites varius, (iii) Gondisporites raniganjensis, (iv) Densipollenites magnicorpus, and (v) Krempipollenites indicus in ascending order from the subsuface rock strata. The lithologically identified strata Talchir Formation in borecores TRBD-2 and TRBD-3 is palynologically dated late Early Permian in having the Scheuringipollenites barakarensis and the Faunipollenites varius palynozones. Subsequently, the part of Barakar strata in these borecores corroborates with Barakar Formation. In borecore TRBD-3, the Barren Measures rocks do not match with the palynological dates, and are affiliated with the palynoflora of the Raniganj Formation. In TROD-1, the strata identified as Barakar Formation is dated Late Permian in having Gondisporites ranigangensis Palynozone; while that of Barren Measures Formation is palynologically dated Early Triassic having Krempipollenites indicus Palynozone. The palynology has helped in the precise dating of the Lower Gondwana succession of Odari and Bartikhurd blocks in Tatapani-Ramkola Coalfield of South Rewa Gondwana Basin.

4 illus, 8 tables, 6 ref

003391   Tiwari S;Jain A;Sarkar S;Jain S;Gwal A K (Space Science Lab, Physics Dep, Barkatullah University, Bhopal, Madhya Pradesh, Email: suni.tiwari@yahoo.co.in) : Ionospheric irregularities at Antarctic using GPS measurements. J Earth Syst Sci 2012, 121(2), 345-53.

Purpose of the work is to study the behaviour of the ionospheric scintillation at high latitude during geomagnetically quiet and disturbed conditions which is one of the most relevant themes in the space weather studies. Scintillation is a major problem in navigation application using GPS and in satellite communication at high latitudes. Severe amplitude fading and strong scintillation affect the reliability of GPS navigational system and satellite communication. To study the effects of the ionospheric scintillations, GPS receiver installed at Antarctic station Maitri (Geog. 70.76°S; 11.74°E) was used. The data is collected by using GISTM 4004A, NOVATEL'S GPS receiver during March 2008. Studies show that percentage occurrence of phase scintillation is well correlated with geomagnetic activity during the observation period. The result also shows that very intense scintillations can degrade GPS based location determination due to loss of lock of satellites. These findings indicate that the dependence of scintillations and irregularity occurrence on geomagnetic activity is associated with the magnetic local time (MLT). Large number of patches are reported and their activity depends on the magnetic activity index.

2 illus, 29 ref

003390   Tahernia N;Khodabin M;Mirzaei N;Eskandri Ghadi M (Geophysics Dep, Science and Research Branch, Islamic Azad University, Tehran, Iran, Email: tahernia@piau.ac.ir) : Statistical models of interoccurrence times of Iranian earthquakes on the basis of information criteria. J Earth Syst Sci 2012, 121(2), 463-74.

By analyzing the seismic catalogue of Iran, the probability distributions of interoccurrence times of earthquakes were investigated for different seismotectonic settings. Several probability distributions were applied to data from major seismotectonic provinces in different cut-off magnitudes and the distribution parameters were determined through the method of maximum likelihood. With the help of goodness-of-fit tests (AIC and BIC criteria based on information theory, Kolmogorov-Smirnov test) and the coefficient of determination, we have found that the gamma statistics and generalized normal statistics coexist in interoccurrence time statistics. Results imply that a transition from a generalized normal regime to a gamma regime occurs if the threshold magnitude in certain seismotectonic regions (Alborz-Azarbayejan, Zagros, and Central-East Iran) is changed.

7 illus, 5 tables, 28 ref

003389   Sujatha E R;Rajamanickam G V;Kumaravel P (NO, School of Civil Engineering, SASTRA University, Thanjavur, Tamil Nadu, Email: r.evangelin@gmail.com) : Landslide susceptibility analysis using probabilistic certainty factor approach: a case study on Tevankarai stream watershed, India. J Earth Syst Sci 2012, 121(5), 1337-50.

Reports the use of a GIS based Probabilistic Certainty Factor method to assess the geo-environmental factors that contribute to landslide susceptibility in Tevankarai Ar sub-watershed, Kodaikkanal. Landslide occurrences are a common phenomenon in the Tevankarai Ar sub-watershed, Kodaikkanal owing to rugged terrain at high altitude, high frequency of intense rainfall and rapidly expanding urban growth. The spatial database of the factors influencing landslides are compiled primarily from topographical maps, aerial photographs and satellite images. They are relief, slope, aspect, curvature, weathering, soil, land use, proximity to road and proximity to drainage. Certainty Factor Approach is used to study the interaction between the factors and the landslide, highlighting the importance of each factor in causing landslide. The results show that slope, aspect, soil and proximity to roads play important role in landslide susceptibility. The landslide susceptibility map is classified into five susceptible classes - low, very low, uncertain, high and very high - 93.32% of the study area falls under the stable category and 6.34% falls under the highly and very highly unstable category. The relative landslide density index (R index) is used to validate the landslide susceptibility map. R index increases with the increase in the susceptibility class. This shows that the factors selected for the study and susceptibility mapping using certainty factor are appropriate for the study area. Highly unstable zones show intense anthropogenic activities like high density settlement areas, and busy roads connecting the hill town and the plains.

5 illus, 5 tables, 51 ref

003388   Srivastava R K;Sinha A K;Suresh Kumar (Centre of Advanced Study, Geology Dep, Banaras Hindu University, Varanasi-221 005, Email: rajeshgeolbhu@yahoo.com) : Geochemical characteristics of mesoproterozoic metabasite dykes from the Chhotanagpur gneissic terrain, eastern India: implications for their emplacement in a plate margin tectonic environment. J Earth Syst Sci 2012, 121(2), 509-23.

Number of mafic intrusive bodies (mostly dykes) are exposed in the Chhotanagpur Gneissic Terrain (CGT). Most dykes trend in ENE-WSW to E-W following major structural trends of the region. These metabasite dykes show granoblastic to grano-nematoblastic textures and contain hornblende, plagioclase, chlorite, quartz and epidote which suggest their metamorphism under amphibolite grade P-T conditions. Although no radiometric age is available for the metabasite dykes, field relationships with host rock and available geochronology on granitoids suggest their emplacement during Mesoproterozoic. Geochemical characteristics of these dykes classify them as low-K tholeiite to medium-K calcalkaline type. At least two types of metabasite dykes are recognized on the basis of their HFSE contents; one group shows entirely calc-alkaline nature, whereas the other group has rocks of tholeiite-calc-alkaline series. High Mg# observed in a number of samples indicates their derivation from primary melt. Multielement spidergrams and rare-earth element patterns observed in these samples also corroborate their derivation from different magma batches. Trace element patterns observed for Nb-Ta, Hf-Zr, Sr and Y suggesting involvement of subduction related processes in the genesis of CGT metabasite dykes. Perceived geochemical characteristics suggest that metamorphism did not affect much on the chemistry of metabasites but source region, responsible for the generation of CGT metabasites, was possibly modified during subduction process. The study suggests that magma generated in a destructive plate setting fed the Mesoproterozoic mafic dykes of the CGT.

11 illus, 1 table, 67 ref

003387   Srivastava J;Farooqui A;Hussain S M (NO, Birbal Sahni Institute of Palaeobotany, 53 University Road, Lucknow-226 007, Email: caprice2628@yahoo.com) : Vegetation history and salinity gradient during the last 3700 years in Pichavaram estuary, India. J Earth Syst Sci 2012, 121(5), 1229-37.

Palaeoclimate, palaeoecological and palaeoshoreline studies were carried out for a 2.5 m deep sediment core deposited since <126>3700 yrs BP in the central part of Pichavaram mangrove wetland, Cauvery river delta. Presently, the study area is dominated by Avicennia officinalis, A. marina and Suaeda sp. with fringes of Rhizophora sp. along the backwater channel. Based on sedimentology, palynological and thecamoebian analysis, it is inferred that since 2100 yrs BP the climate amelioration took place from warm and humid with strengthened monsoon to a dry and arid climate coupled with weakened monsoon condition inducing changes in ecology vulnerable for mangroves. Consequently, the vegetation too evolved from moist deciduous/evergreen forest to mixed deciduous forest and a reduction in mangrove diversity. The qualitative and quantitative study show a decline in the mangroves since the last millennium which may be attributed to the increased salinity along with enhanced anthropogenic activities in Pichavaram estuary. This is reflected by the dominance of salt tolerant mangrove associates since the last millennium.

3 illus, 1 table, 33 ref

003386   Sitharam T G;James N;Vipin K S;Ganesha Raj K (Civil Engineering Dep, Indian Institute of Science, Bangalore-560 012, Email: naveenjames7@gmail.com) : Seismicity and seismic hazard for Karnataka State. J Earth Syst Sci 2012, 121(2), 475-90.

Presents a detailed study on the seismic pattern of the state of Karnataka and also quantifies the seismic hazard for the entire state. In the work, historical and instrumental seismicity data for Karnataka (within 300 km from Karnataka political boundary) were compiled and hazard analysis was done based on this data. Geographically, Karnataka forms a part of peninsular India which is tectonically identified as an intraplate region of Indian plate. Due to the convergent movement of the Indian plate with the Eurasian plate, movements are occurring along major intraplate faults resulting in seismic activity of the region and hence the hazard assessment of this region is very important. Apart from referring to seismotectonic atlas for identifying faults and fractures, major lineaments in the study area were also mapped using satellite data. The earthquake events reported by various national and international agencies were collected until 2009. Declustering of earthquake events was done to remove foreshocks and aftershocks. Seismic hazard analysis was done for the state of Karnataka using both deterministic and probabilistic approaches incorporating logic tree methodology. The peak ground acceleration (PGA) at rock level was evaluated for the entire state considering a grid size of 0.05°x0.05°. The attenuation relations proposed for stable continental shield region were used in evaluating the seismic hazard with appropriate weightage factors. Response spectra at rock level for important Tier II cities and Bangalore were evaluated. The contour maps showing the spatial variation of PGA values at bedrock are presented in this work.

13 illus, 5 tables, 44 ref