024788   Gadgil M;Ranjit Daniels R J;Ganeshaiah K N; Narendra Prasad S;Murthy M S R;Jha C S;Ramesh B R;Subramanian K A (NO, Agharkar Research Institute, G.G. Agarkar Road, Pune-411 004, Email: madhav.gadgil@gmail.com) : Mapping ecologically sensitive, significant and salient areas of western ghats: proposed protocols and methodology. Curr Sci 2011, 100(2), 175-82.

The Western Ghats Ecology Expert Panel (WGEEP) of the Ministry of Environment and Forests, Government of India (GOI) has been asked to identify ecologically sensitive areas (ESAs) along the Western Ghats, and to suggest how to manage them. The concept of ESAs has been extensively discussed in the literature. Several ESAs have been set up in India over the last 22 years under the Environment Protection Act, 1986, and a GOI committee under the chairmanship of Pranob Sen has proposed certain criteria for identification of ESAs. However, WGEEP noted that we still lack a global consensus either on the criteria to define ESAs or on a workable methodology to identify them. Furthermore, there are no clear guidelines on the management regime that should prevail in ESAs, and the Pranob Sen Committee has not addressed this issue at all. Hence, WGEEP decided to undertake an exercise of defining ESAs and developing a workable methodology to assign levels of ecological significance/sensitivity as a first step towards putting ESAs on the map of the Western Ghats. This article provides a report on the outcome of a series of discussions and consultations held by WGEEP to build a consensus on defining and mapping ESAs. It hopes to provoke discussion and feedback from a wider section of experts, with the aim of finalizing a generic methodology for mapping ESAs in other ecologically significant, biodiversity-rich areas within and outside the country. We hope to shortly prepare a companion paper that will address the equally vital management issues.

3 illus, 2 tables, 31 ref

024787   Dwivedi S B;Theunuo K (Civil Engineering Dep, Institute of Technology, Banaras Hindu Univ, Varanasi-221 005, Email: sbd.civ@itbhu.ac.in) : Two-pyroxene mafic granulites from patharkhang, Sillong-Meghalaya gneissic complex. Curr Sci 2011, 100(1), 100-5.

The two-pyroxene mafic granulite of Patharkhang area belongs to the Shillong-Meghalaya Gneissic Complex and includes orthopyroxene-clinopyroxene-hornblende-plagioclase ± quartz as common mineral assemblages, which are stable at thermal peak of regional metamorphism. In this study electron probe microanalysis data have been used to discuss mineral chemistry and pressure-temperature (P-T) condition of metamorphism of the mafic granulite. The average P-T condition suggests a thermal peak of metamorphism at 1029 ± 62°C/7.6 ± 1.7 kbar.

4 illus, 4 tables, 17 ref

024786   Dora M L;Nair K K K;Shasidharan K (Geological Survey of India, Central Region, Operation Maharashtra, Nagpur-440 006, Email: dorageol@gmail.com) : Occurrence of platinum group minerals in the Western Bastar craton, Chandrapur district, Maharashtra. Curr Sci 2011, 100(3), 399-404.

The occurrence of platinum group minerals (PGMs) and gold is reported in association with Fe-Ni-Cu sulphides and chromite in mafic-ultramafic rocks (gabbro-pyroxenite) of Gondpipri area in the Western Bastar Craton. These minerals are mainly moncheite and palladium moncheite and are identified using scanning electron microscope. Chemical analysis of bed-rock samples shows anomalous platinum group element values in which palladium dominates over platinum. This communication highlights the distribution of PGMs and their mineralogical association.

^ssc 5 illus, 3 tables, 32 ref

024785   Chowksey V;Joshi P;Maurya D M;Chamyal L S (Geology Dep, The M.S. Baroda Univ, Vadodara-390 002, Email: dmmaurya@yahoo.com) : Ground penetrating radar characterization of fault-generated quaternary colluvio-fluvial deposits along the seismically active Kachchh mainland fault, Western India. Curr Sci 2011, 100(6), 915-21.

Quaternary colluvio-fluvial deposits in the seismically active Kachchh Mainland Fault (KMF) zone have been studied using ground penetrating radar (GPR). The deposits form a north-sloping <126> 2-3 km wide, deeply dissected surface to the north of the KMF scarps developed in Mesozoic rocks forming the northern limb of the Habo dome. The northward slope of the surface and decreasing trend of incision towards the north are attributed to neotectonic activity along KMF. Exposed river sections and trench sections correlate well with the GPR data. The various sedimentary facies identified vary from bouldery gravel to finer gravel and gravelly sand. Discontinuous wavy radar reflections relate to bouldery gravel deposits, whereas the parallel discontinuous reflections indicate finer gravels or gravelly sands. In contrast, the parallel and continuous radar reflections characterize the well-stratified gravels. The study demonstrates the utility of GPR in colluvial and reworked colluvial deposits in active fault zones.

5 illus, 25 ref

024784   Chaujar R K (NO, Wadia Institute of Himalayan Geology, Dehradun-248 001, Email: rchaujar@gmail.com) : Lichenometric studies and pindari glacier retreat. Curr Sci 2010, 99(10), 1306-7.

1 table, 6 ref

024783   Chandrasekhar P;Martha T R;Venkateswarlu N; Subramanian S K;Kamaraju M V V (National Remote Sesing Centre, Indian Space Research Organisation, Hyderabad-500 625, Email: chandrasekhar_p@nrsc.gov.in) : Regional geological studies over parts of deccan syneclise using remote sensing and geophysical data for understanding hydrocarbon prospects. Curr Sci 2011, 100(1), 95-9.

An integrated study using remote sensing and multi-geophysical data was carried out over parts of Deccan Syneclise, for eliminating the inherent ambiguities associated with each of the individual methods, and to understand the hydrocarbon prospects. The subsurface sections constructed using geophysical data such as gravity, electrical resistivity, deep resistivity sounding, magnetotellurics and seismics along various pro-files were interpreted for identification of subsurface faults along with their stratigraphic association. The locations of these faults were projected vertically upwards onto the ground surface and marked as point locations on the map in order to facilitate conjunctive study with satellite data interpretation by superimposing one over the other. Additionally, some more regional faults were interpreted from gravity data and superimposed over the above. A prominent geomor-phic anomaly was also interpreted from satellite data and correlated with geophysical signatures. Based on

6 illus, 1 table, 9 ref

024782   Bhat G S;Rao P L;Sangolli V G (Centre for Atmospheric and Oceanic Sciences, Indian Institute of Science, Bangalore-560 012, Email: bhat@caos.iisc.ernet.in) : Atmospheric boundary-layer across hadley and ferrel cells over the Indian ocean. Curr Sci 2010, 99(10), 1178-83.

A Southern Ocean Pilot cruise covering the latitudes from 10°N to 56°S in the open Indian Ocean was carried out during January-February 2004. Surface and upper air data collected during this cruise are reported here. It is shown that the broad features of the atmosphere, in particular that of temperature, follow the tropical and mid-latitude weather expected during January-February in this region. However, the atmospheric boundary-layer shows large variations, both in its height and structure between tropics and high latitudes. Strong influence of the surface heat flux on boundary layer structure is clearly seen. Humidity field reveals several local maxima and minima, suggesting a laminated atmosphere with air from different sources moving almost unmixed in adjacent layers.

8 illus, 20 ref

024781   Bali R;Nawaz Ali S (Centre of Advanced Study in Geology, Lucknow Univ, Lucknow-226 007, Email: rameshbali@rediffmail.com) : Dynamics of pindari glacier during the last 6 years. Curr Sci 2010, 99(10), 1307.

4 ref

024780   Babu Govindha Raj K (RS & GIS-Applications Area, National Remote Sensing Centre, Indian Space Research Organisation, Balanagar, Hyderabad-500 625, Email: babugovindraj@gmail.com ) : Recession and reconstruction of Milam glacier, Kumaon Himalaya, observed with satellite imagery. Curr Sci 2011, 100(9), 1420-5.

The Himalaya is the adobe of one of the world's largest and mostly inaccessible area of glaciers outside the polar regions and provides glacier-stored water to the major Indian river basins. Various studies suggest that many of the Himalayan glaciers have receded in recent decades due to climate forcing. Temporal satellite data analysis shows that the Milam Glacier in Goriganga Basin, Kumaon Himalaya receded 1328 m laterally and 90 m vertically during 1954-2006. The enhanced satellite imagery helps in establishing the extent of the glacier in inaccessible terrains like the Himalaya.

6 illus, 30 ref

024779   Arivazhagan S;Anbazhagan S (Geology Dep, Periyar Univ, Salem-636 011, Email: anbu02@gmail.com) : Characterization of reflectance spectra of lunar analog rocks: gabbro and norite. Curr Sci 2011, 100(5), 761-8.

Gabbro and noritic rocks are of particular interest to lunar scientists because they stratigraphically represent the deeper zones of the lunar crust. This communication reports reflectance spectra under 350-2500 nm for lunar analog rocks like gabbro and norite and a comparison with mineralogy and chemical composition. The gabbro and norite distinctly vary in terms of albedos of reflectance spectra. However, these rocks have common absorption bands in the visible-near infrared and SWIR spectral range. Norite has pyroxene absorption at 1072 nm, whereas this absorption is absent in gabbro. Similarly, the broader absorption band at 1200 nm in gabbro is probably due to overlapping absorption by crystalline plagioclase feldspar and the presence of pyroxene. Overall, minor variation in absorption bands, percentage of albedos and band depth are the diagnostic features useful for remote mapping of similar rock types on the lunar surface.

4 illus, 4 tables, 49 ref

024778   Anilkumar N;Rahul Mohan;Shukla S K;Pednekar S M;Sudhakar M;Ravindra R (NO, National Centre for Antarctic and Ocean Research, Headland Sada, Goa-403 804, Email: anil3321@yahoo.co.in) : Signature of coastal upwelling in Prydz bay, East Antarctica during austral summer 2006. Curr Sci 2010, 99(10), 1390-4.

This study discusses the upwelling observed in Prydz Bay, coastal waters of East Antarctica. In February 2006, as a part of expedition to Larsemann Hills (East Antarctica) three hourly conductivity, temperature, depth (CTD) observations were carried out for three consecutive days in Prydz Bay coastal waters. This helped to understand temporal variability of hydro-graphic parameters in this region. An upward movement of subsurface waters was identified at around 13:30 h on 24 and 08:00 h on 26 February 2006. In situ micro algal concentration indicated maximum chlorophyll, diatom and green algal concentration at 13:03 h on 24 February. This study suggests that major cause for upward movement of water in the Prydz Bay area could be the influence of local wind forcing. XBT observations made outside the Prydz Bay showed temperature variations from -1.7°C to 0.4°C between 50 and 150 m. At 64°S 70°E in the north-south transect, a temperature minimum of <126>1.68°C was observed at 97 m. This could probably be due to remnants of the previous winter water. Cireum polar deep water was identified outside the Prydz Bay area whereas features of high salinity shelf water were identified inside the Bay.

7 illus, 26 ref

023656   Yadugiri V T (NO, , No. 1184, 5th Main, Sector-7, H.S.R. Layout, Bangalore-560 102, Email: vtyadugiri@gmail.com) : Climate change: the role of plant physiology. Curr Sci 2010, 99(4), 423-5.

10 ref

023655   Veena Prasanna M;Rasheed M A;Madhavi T; Kalpana G;Patil D J;Dayal A M (National Geophysical Research Institute (Council of Scientific and Ind, Uppal Road, Hyderabad-500 606, Email: dayalisotope@rediffmail.com) : Light gaseous hydrocarbon anomalies in the near-surface soils of Sagar district, vindhyan basin, India. Curr Sci 2010, 99(11), 1586-90.

Seepage of natural gas was reported from some bore wells located in a few agricultural fields in Piparia, Bhutoli and Rahatgarh areas, Sagar District, Madhya Pradesh, India. Geochemical prospecting survey has been carried out in Sagar District to study the seepage of natural gas associated with adsorbed soil gas anomalies in order to establish an upward migration of hydrocarbons from the subsurface reservoir. In the present study, adsorbed light gaseous hydrocarbon analyses show the presence of moderate to low concentrations of methane (C₁) 1 to 104 ppb, ethane (C₂) 1 to 14 ppb, propane (C₃) 1 to 10, i'-butane (iC₄) 1 to 9 ppb and n-butane (nC₄) 1 to 8 ppb in the soil samples. The carbon isotopic composition of methane ranges between -29.9% and -52.2% (PeeDee Belemnite), suggesting that these gases are of thermogenic origin. Adsorbed soil gas and carbon isotope studies show good regional evaluation of hydrocarbon potential.

^ssc3 illus, 3 tables, 20 ref

023654   Tiwari V M;Singh B;Arora K;Kumar S (NO, National Geophysical Research Institute (CSIR), Hyderabad-500 606, Email: vmtiwari@ngri.res.in) : Potential of satellite gravity and gravity gradiometry in deciphering structural setting of the himalayan collision zone. Curr Sci 2010, 99(12), 1795-1800.

During the last decade, three dedicated satellite gravity missions (CHAMP, GRACE and GOCE) have greatly improved the knowledge of the static and dynamic gravity field of the Earth. Bouguer gravity anomalies (BGA) derived from global gravity models (e.g. EGM2008), which consist of GRACE satellite observations and terrestrial gravity data, are analysed to demonstrate through selected applications, their potential use in studying large scale geological features of the Himalaya, where little or no terrestrial data are available. A constrained 3D lithospheric density model over a part of the Eastern Himalayan region is constructed from modelling of BGA and utilized to calculate forward responses of selected gravity gradient (GG) tensors, highlighting certain aspects of the structural features of the Himalayan Collision Zone (HCZ). In addition, GG are also computed directly from BGA by Fourier transformation to study the additional information content they may provide. This exercise may demonstrate the extra advantages of modelling gravity gradiometry measurements, which is of high contemporary relevance in view of the fact that satellite gravity gradient data from the ongoing GOCE mission will be available shortly. We find that structural features like Main Boundary Thrust, Main Central Thrust are sharply reflected in GG and combined interpretation of BGA and GG can better resolve the locations and possibly the depth extent of the density anomalies. BGA is also utilized to constrain crustal thickness variation and used along with topography to estimate variation of effective elastic thickness across the Eastern Himalayan region.

7 illus, 38 ref

023653   Taori A;Sathishkumar S;Gurubaran S (NO, National Atmospheric Research Laboratory, Gadanki-517 112, Email: alok.taori@gmail.com) : Variations in low-latitude middle atmospheric thermal structure during the 15 january 2010 solar eclipse. Curr Sci 2010, 99(11), 1578-81.

The altitude profiles of middle atmospheric temperatures are examined to study the effects of the solar eclipse on 15 January 2010 as it passed through the Indian longitudes. It was found that thermal structures exhibited strong inversion layers on the eclipse day, with large temperature deviations around 45, 50, 60, 75, 82 and 92 km altitudes compared to normal days. Fourier analysis revealed no significant changes in the gravity wave characteristics; however, the amplitudes of the observed waves were significantly higher (~two times) compared to the normal days.

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023652   Srivastava H N;Verma M;Bansal B K (No. 128, Pocket A, Sarita Vihar, New Delhi-110 079, Email: bansalbk@nic.in) : Seismological constraints for the 1905 Kangra earthquake and associated hazard in northwest India. Curr Sci 2010, 99(11), 1549-59.

The Kangra earthquake of 1905 occurred when seis-mological instrumentation with low-gain optical recording seismographs were sparsely located. However, attempts are being made in recent times not only to refine the epicentral data, but even to postulate new earthquakes to explain the secondary meizoseismal area near Dehradun. Careful re-examination and analysis of data reveal that the interpretation given is somewhat misleading as the data provided fit better with a large deeper aftershock of the Kangra earthquake which occurred within a few minutes of the main shock. The meizoseismal area near Dehradun was indeed a site-response effect similar to that during other earthquakes like the Bihar Nepal 1934, Bhuj 2001 and Mexico 1985. Causes for the generation of such meizoseismal areas about 100-500 km away from the epicentre are discussed. It has been highlighted that for earthquake hazard assessment and disaster management, the role of secondary meizoseismal areas should not be ignored.

5 illus, 48 ref

023651   Srinivasan G (Geology Dep, Toronto Univ, Toronto, M5S 3B1, Canada, Email: srini@geology.utoronto.ca) : Early earth: insights from the meteorites. Curr Sci 2010, 99(12), 1762-9.

The evolution of planetary bodies like 4 Vesta and terrestrial planets (e.g. Earth, Moon, Mars) involved accretion, melting, differentiation, formation of silicate mantle and metallic core, and mantle differentiation. Determination of the time scales of these processes forms the fundamental basis for understanding the early evolution of the Earth. The decay of ¹⁸²Hf (half-life <126>9 Ma) to ¹⁸² W and ¹⁴⁶Sm (half-life ~ 103 Ma) to ¹⁴²Nd has been used to determine time scales of metal-silicate differentiation leading to core formation of planets and mantle differentiation resulting in eruption of basalts on planetary bodies which are preserved even today on 4 Vesta, but not preserved on the Earth. By using the meteorite data as a baseline, one can establish a time frame for early evolution of Earth.

70 ref

023650   Singh L;Soni P (Ecology and Environment Div, Forest Research Institute, Dehradun-248 006, Email: lalsingh82@gmail.com) : Binding capacity and root penetration of seven species selected for revegetation of uranium tailings at Jaduguda in Jharkhand, India. Curr Sci 2010, 99(4), 507-13.

Uranium from ores mined at the three mines -Jaduguda, Bhatin and Narwapahar (Jharkhand) - is processed in the mill and the waste emerges as tailings. The recorded radioactivity level in these tailings is very low, but to avoid any long-term effect of these tailings on the atmosphere, humans, cattle as well as native flora and fauna, the tailings are covered with 30 cm layer of soil. This reduces the gamma radiation and radon emission levels. However, to consolidate the soil covering the tailings on a sustainable basis, the area needs to be revegetated by plant species having shallow root systems, good conservation value and low canopy cover. Another important criterion for selection of species is that they should not have any ethnobotani-cal relevance to the surrounding villages. Considering these criteria, seven native plant species of forestry origin, viz. Colebrookea oppositifolia, Dodonaea vis-cosa, Furcraea foetida, Imperata cylindrica, Jatropha gossypifolia, Pogostemon benghalense and Saccharum spontaneum have been selected for experimental trials. We describe here the strategies adopted for consolidation of radioactivity in tailings, revegetation practices used and the ecological role of the selected species in consolidating the tailings.

^ssc7 tables, 25 ref

023649   Sharma R (NO, National Institute of Oceanography (Council of Scientific and Industri, Dona Paula, Goa-403 004, Email: rsharma@nio.org) : First nodule to first mine-site: development of deep-sea mineral resources from the Indian ocean. Curr Sci 2010, 99(6), 750-9.

Polymetallic nodules found on the deep seafloor (<62>4000 m water depth) have been recognized as an alternative source for certain metals, when land deposits get exhausted. Spread over millions of square kilometres on the seafloor of all the oceans, these deposits contain as much as 40% of combined metals (Mn + Fe + Cu + Ni + Co) and are generally found in the international waters (beyond the exclusive economic zone of any country). India is one of the eight 'Pioneer Investors' in the world with exclusive rights over an area of 75,000 sq. km in the Central Indian Ocean for the exploration and future exploitation of these mineral deposits; the others being France, Russia, Japan, Korea, China, Interoceanmetal, Poland and Germany in the Pacific Ocean. Ever since the recovery of nodules in 1981 in the equatorial Indian Ocean, India has conducted extensive exploration resulting in the identification of first-generation mine-site; assessment of potential environmental impact, creation of data for mining; as well as development of technologies for metallurgical processing and mining of the deep-sea minerals. Some of the key factors responsible for the success of the programme have been multi-agency networking, mixing experience with youth and emphasis on high-quality research. The programme has contributed in terms of science and policy, publications and patents, capacity building and diversification into exploration of other marine minerals. This article traces the development in the capabilities of deep-sea mineral exploration and exploitation in the Indian Ocean.

3 illus, 6 tables, 49 ref

023648   Santosh Kumar (Geology Dep, Kumaun Univ, Nainital-263 002, Email: skyadavan@yahoo.com) : Magnetite and ilmenite series grantioids of ladakh batholith, northwest Indian himalaya: implications on redox conditioons of subduction zone magmatism. Curr Sci 2010, 99(9), 1260-4.

Multiple felsic magmatic pulses north of the Indus-Tsangpo Suture Zone constitute the Ladakh batholith in the Northwest Indian Higher Himalaya, which is characterized largely by calc-alkaline metaluminous (I-type) granitoids with abundant microgranular enclave formed in a subduction setting. Mineralogical and magnetic susceptibility (MS) parameters of granitoids exposed in the northwestern, central and southeastern parts of the Ladakh batholith have been evaluated in order to understand the redox conditions (magnetite versus ilmenite series) of felsic melts with implication on the nature of the subducting source materials. Average MS values of granitoids range widely from 0.02 x 10^-3 to 44.54 x 10 SI units, corresponding to both magnetite series (MS <62> 3 x 10^-3 SI units; oxidized type) and ilmenite series (MS ≤ 3 x 10^-3 SI units; reduced type) granites, which is broadly consistent with the observed variations in mafic to felsic minerals (low to high), colour index (leucocratic to mesocratic), modal composition (hbl-bt quartz mon-zodiorite-granodiorite-tonalite), biotite composition (Fe/Fe +Mg = 0.42-0.80) and whole-rock molar A1₂O₃/CaO + Na₂O + K₂O ratio (0.74-1.09) of granitoids of the Ladakh batholith. Although throughout the Ladakh batholith magnetite series granites dominate over the ilmenite series granites, the ratio of magnetite/ilmenite series granites decreases gradually from the northwestern to the southeastern parts of the Ladakh batholith along its strike-length, which primarily resulted from varying amounts and types of subducting materials and contamination with mantle wedge source. At places, oxidizing condition of granitoid melts becomes elevated because of mafic (enclave) and felsic magma interaction in the open system, and granitoids are locally reduced to ilmenite series close to either intrusive or tectonic contacts.

2 illus, 1 table, 40 ref

023647   Sadhuram Y;Maneesha K;Ramana Murty T V (National Institute of Oceanography, Regional Centre (CSIR), 176, Lawsons Bay Colony, Visakhapatnam-530 017, Email: sadhuram@nio.org) : Importance of upper ocean heat content in the intensification and translation speed of cyclones over the Bay of Bengal. Curr Sci 2010, 99(9), 1191-4.

^ssc2 illus, 1 table, 13 ref

023646   Ravi Kumar M;Singh A (NO, National Geophysical Research Institute (CSIR), Hyderabad-500 007, Email: kumar_mrl@rediffmail.com) : Seismic anisotropy of the Indian tectonic plate: deciphering continental scale mantle deformation patterns. Curr Sci 2010, 99(12), 1751-61.

This paper reviews the seismic anisotropy of the Indian tectonic plate with an attempt to decipher whether the distinct stable continental shield elements and actively deforming regions show disparate character and whether plate motion-related deformation is dominant compared to anisotropy frozen in the lithosphere. Large delay times and fast polarization azimuths aligned close to the direction of absolute plate motion direction suggest shear related to asthenospheric flow at the base of the lithosphere as the overall causative mechanism for forging anisotropy within the Indian shield. The strong correlation between fast polarization azimuths and the absolute plate motion direction in the northern part of the shield where the lithosphere is thick, can be attributed to the lattice preferred orientation of the fast 'a'-axis of olivine being oriented in the direction of plate motion as a result of increased basal shear due to the relative motion between the fast moving plate and the sub-lithospheric mantle. Modelling the dependence of splitting parameters on incoming polarization brings out two layers of anisotropy beneath the shield region, with a stronger anisotropy in the bottom layer being related to asthenospheric flow and a weaker one in the upper layer to anisotropy frozen in the lithosphere. The strike parallel trends in the Himalaya and foredeep argue in favour of collision induced litho-spheric strain as the primary cause for forging the anisotropy. Interestingly, the anisotropic directions in the Nepal Himalaya are predominantly in the direction of Indian plate motion, in contrast to the directions in Sikkim Himalaya and other young mountain belts. Superposition of the effects of deformation due to plate motion, mantle flow due to compression as a result of collision with a contribution from crustal anisotropy can result in a complex pattern of anisotropy, depending on their relative strengths and orientations.

8 illus, 84 ref

023645   Rautela P;Joshi G C;Bhaisora B (Disaster Mitigation and Management Centre, Disaster Management Dep, Uttarakhand Secretariat, Rajpur Road, Dehradun-248 001, Email: piyooshrautela@gmail.com) : Seismic vulnerability and risk in the Himalayan township of Mussoorie, Uttarakhand, India. Curr Sci 2010, 99(4), 521-6.

Rapid visual screening technique has been resorted to for assessing seismic vulnerability and risk in the Himalayan township of Mussoorie that falls in Zone IV of the Earthquake Zoning Map of India. Damage during an earthquake in this zone is expected to reach MSK intensity VIII. A total of 3344 structures in 11 residential wards of the town were surveyed in the field. Data collected in the field were analysed under GIS environment which suggests that a total of 615 (18%) buildings show high probability of Grade 5 damage and very high probability of Grade 4 damage class. The economic loss likely to be incurred is estimated to be of the order Rs 238.85 crore in the township of Mussoorie alone. Modest estimates suggest that 369 persons might sustain grievous injuries in this event. The study highlights the fact that some of the lifeline buildings are under severe threat and are required to be retrofitted or replaced on priority basis.

^ssc4 illus, 17 ref

023644   Ramadass G A; (NO, National Institute of Ocean Technology, Velachery-Tambaram Main Road, Narayanapuram, Pallikaranai, Chennai-600 100) : Deep-ocean exploration using remotely operated vehicle at gas hydrate site in Krishna-Godavari basin, Bay of Bengal. Curr Sci 2010, 99(6), 809-15.

Work class remotely operated vehicle (ROV) rated for 6000 m depth of operation (ROSUB 6000) has been developed at the National Institute of Ocean Technology, Chennai, for deep-ocean resource studies. This system is being developed for the exploration of deep-sea mineral deposits such as poly-metallic nodules, gas hydrates, cobalt crust and other deep-ocean scientific observations in the Indian waters. The first ROV-based deep-water scientific expedition was performed to decipher the surface expression of gas hydrate at a depth of 1017 m in the Krishna-Godavari basin, Bay of Bengal, during September 2009. High-resolution bathymetry with multibeam sonar, vertical profiles of dissolved oxygen and water temperature were also collected in real time using ROV. Live images of sea-floor habitats and deep-sea organisms such as fishes, shrimp, corals, holothurians and polychaetes were recorded and identified. Probable deep-water coral reef province is being established from deep waters of the Bay of Bengal and the exploration results have brought out chemosynthetic habitat at the expedition site in Bay of Bengal.

12 illus, 1 table, 25 ref

023643   Pravendra Kumar;Singh P V (Soil & Water Conservation Engineering Dep, G.B. Pant Agriculture and Technology Univ, Pantnagar-263 145, Email: pravendrak_05@yahoo.co.in) : Prediction of annual maximum daily rainfall based on probability analysis. Envir Ecol 2011, 29(1), 39-41.

Probability analysis was carried out to evaluate the most suitable probability distribution for prediction of annual maximum daily rainfall at Azamgarh (Uttar Pradesh). The daily rainfall data of 20 years (1982-2001) obtained from meteorological observatory, Azamgarh were used for the analysis. In this study, an attempt was made to find out the goodness of fit of the observed annual maximum daily rainfall with the predicted values of rainfall computed by using theoretical probability distributions namely, Log Pearson Type III, Log Normal and Gumbel distributions. The best theoretical probability distribution was adjudged by comparing the sum of Chi-square values for each distribution corresponding to all return periods. Based on the smallest value of Chi-square as compared to other two distributions ; log normal distribution was found to be best probability model for predicting annual maximum daily rainfall of Azamgarh.

1 illus, 1 table, 11 ref

023642   Paul A;Khan M L (Forestry Dep, North Eastern Regional Institute of Science and Technology (Deemed Uni, Nirjuli-791 109, Email: ashishpaul11@gmail.com) : Water: an eco-friendly and energy-efficient resource for milling in rural Arunachal Pradesh. Curr Sci 2010, 99(4), 417.

1 illus, 4 ref

023641   Patel D S;Bharatam P V (Medicinal Chemistry Dep, National Institute of Pharmaceutical Education and Research Sector 67, S.A.S. Nagar, Mohali-160 062, Email: pvbharatam@niper.ac.in) : Carbones: divalent C(0) compounds. Curr Sci 2010, 99(4), 425-6.

3 illus, 14 ref

023640   Mondal N C;Singh V P (National Geophysical Research Institute (Council of Scientific and Ind, Uppal Road, Hyderabad-500 606, Email: ncmgri@yahoo.co.in) : Entropy-based approach for estimation of natural recharge in kodaganar river basin, Tamil Nadu, India. Curr Sci 2010, 99(11), 1560-9.

Entropy-based approach has been developed for estimation of natural recharge in Kodaganar River basin, Tamil Nadu, southern India. Wells were located in a weathered aquifer which exhibits spatial variability in natural recharge. To determine the fractional amount of rainfall (called natural recharge), marginal entropy and transinformation of rainfall and depth to the water table at selected wells were calculated. Then a ratio of transinformation to marginal entropy of rainfall was used as a measure for assessing natural recharge. The mean natural recharge values at 28 wells distributed over the study area were computed. The average recharge rate was about 62.95 mm/yr or 14.48% of local average seasonal rainfall. The calculated annual input of rainfall to groundwater reserves was about 0.11 X 10⁹ m³/yr.

6 illus, 5 tables, 51 ref

023639   Manglik A (NO, National Geophysical Research Institute (CSIR), Uppal Road, Hyderabad-500 606, Email: ajay@ngri.res.in) : New insights into core-mantle boundary region and implications for earth's internal processes. Curr Sci 2010, 99(12), 1733-8.

The core-mantle boundary (CMB) region, a 200-300 km thick zone in the lowermost mantle bounded between the D" discontinuity and CMB, plays a significant role in controlling the dynamical processes in the Earth's interior, both in the mantle and in the core as well as their interaction. Earlier, this region was considered as a thermal boundary layer and/or a compositionally distinct layer. High resolution seis-mological studies of this region over the past one decade coupled with new mineral physics experiments on perovskite at pressure and temperature regimes representing the lowermost mantle conditions have revealed that (i) the D" discontinuity is a phase transition boundary between perovskite and a new post-perovskite phase, (ii) large lateral and vertical variations in shear velocity and density exist within this region, (iii) large anisotropy in the shear velocity exists indicating lateral flow within the CMB zone and vertical flow in the regions of plume upwellings, and (iv) it is possible to estimate the temperature gradients within the zone from identified paired seismic discontinuities, mainly in the regions of Mesozoic subduc-tion. These results have important implications for estimation of the energy budget of the Earth, heat flow out of the core, and radiogenic heat contribution of the mantle leading to improved understanding of the energy available for mantle convection, core cooling and growth of the inner core, geomagnetic field generation, and core-mantle coupling.

3 illus, 47 ref

023638   Lamb S;Watts A (Earth Sciences Dep, Oxford Univ, UK) : The origin of mountains- implications for the behaviour of earth's lithosphere. Curr Sci 2010, 99(12), 1699-1718.

Mountains are an expression of buoyancy in the outermost part of the Earth, caused by density contrasts in the lithosphere and underlying asthenosphere, as described by the principle of isostasy. The biggest density contrast is between the lower density crust and more dense mantle, and so changes in crustal thickness are the main reason for the creation of the planet's highest and most extensive mountain ranges, in the Andes of South America, and the great ranges of Central Asia, in Tibet and the Himalaya. Crustal thickening is primarily a result of crustal shortening, driven by horizontal forces in the lithosphere. The response of the lithosphere to these forces depends on its thickness and rheology, and when tectonic plates converge, mountain ranges will form where the lithosphere is weak and thin, pushed up by the same forces that drive the plates themselves, though limited by the maximum force that can be transmitted across the plate interface. The smaller density contrast between the lithospheric mantle and underlying less dense asthenosphere will also play a subsidiary role in the elevation of mountain belts, depending on changes in lithospheric thickness. The nature of deformation during mountain building is strongly controlled by the interaction of lithosphere of different strengths.

16 illus, 76 ref

023637   Kessarkar P M;Purnachandra Rao V;Naqvi S W A; Chivas A R;Saino T (National Institute of Oceanography, Council of Scientific and Industrial Research, Dona Paula, Goa-403 004, Email: pratimak@nio.org) : Fluctuations in productivity and denitrification in the southeastern arabian sea during the late quaternary. Curr Sci 2010, 99(4), 485-91.

Sedimentological and stable isotopic characteristics of sediments have been studied in a core from the southeastern Arabian Sea containing records of the past 70 ka. Palaeoproductivity proxies such as organic carbon (C_org), total nitrogen (TN) and calcium carbonate (CaCO₃) contents, show high values at the core top and during the Last Glacial Maximum (LGM) and marine isotope stage (MIS) 4, suggesting high productivity, whereas low C_org and CaCO₃ contents are associated with the MIS 1/2 and mid-MIS 3, indicating reduced productivity. The δ¹⁸O values in planktonic foraminifera range between -2.7%₀ and - 0.1%o, with a large glacial-interglacial amplitude Δδ¹⁸ O of ~2.6%o, suggesting changes related to monsoonal precipitation/runoff. The δ¹⁵N values fluctuate between 5.4%₀ and 7.3%₀, signifying variation in denitrification intensity. The δ¹⁵ N indicates an overall increase in denitrification intensity during MIS 1 and MIS 3 and, reduced intensity during MIS 1/2, LGM and mid-MIS 3. Higher primary productivity and reduced denitrification intensity during LGM and MIS 4 might be due to convective winter mixing and more oxygenated subsurface waters. Reduced primary productivity during MIS 1/2 and mid-MIS 3 might be the effect of enhanced precipitation associated with the intensified southwest monsoon fortifying near-surface stratification.

3 illus, 42 ref

023636   Juyal N (Geoscience Div, Physical Research Laboratory, Ahmedabad-380 009, Email: navin@prl.res.in) : Cloud burst-triggered debris flows around Leh. Curr Sci 2010, 99(9), 1166-67.

1 illus, 6 ref

023635   Jaiswal R S;Neela V S;Fredrick S R;Zaveri L (Centre for Study on Rainfall & Radio Wave Propagation, Sona College of Technology, Salem-636 005, Email: senoritta_in@yahoo.co.in) : Characteristics of S-W and N-E monsoon rainfall over Salem. Indian J Radio Space Phys 2011, 40(5), 257-66.

The study of rainfall during various seasons in Salem (11°40'9.97"N, 78°8'27.11"E), a town in southern India has been reported in the present paper. The variability has also been discussed in terms of the accumulated rainfall (R), the number of hours of rainfall (RH) and the average rainfall (avg), as well as the percentage occurrence of very low, low, moderate, heavy, very heavy and extreme rainfall in these seasons. A particular effort has been made to determine the effect of El Nino and La Nina on patterns of rainfall. The meteorological parameters, such as cloud liquid water (CLW), precipitation water (PW) and latent heat (LH) have also been determined for various seasons. The study shows that there exists a significant degree of correlation between rainfall and these meteorological parameters. A functional relationship has also been established between the intensity of convective rainfall and CLW, PW and LH.

4 illus, 4 tables, 18 ref

023634   Jafri S H;Srinivasa Sarma D;Sheikh J M (NO, National Geophysical Research Institute (CSIR), Hyderabad-500 007, Email: syed1401@rediffmail.com) : Hyaloclasities in pillow basalts, south Andaman island, Bay of Bengal, India. Curr Sci 2010, 99(12), 1825-9.

Hyaloclastites and pillow breccias are exposed in the northeastern part of the lower pillow basalt, which constitutes a part of the Andaman ophiolitic sequence, in the southern part of South Andaman Island. The hyaloclastite bands are composed of glass shards and basaltic fragments in a fine-grained matrix. The lower pillow basalts, in which hyaloclastites occur, are tho-leiitic in nature with MORE affinity and slightly LREE-depleted REE pattern. However, their slight LREE depletion and high Ba/Zr ratios (0.23-0.42) relative to N-MORB and LILE (K, Rb, Ba and Sr) enrichment suggest their back-arc basin basalt affinity. The majority of the glass shards and basaltic fragments in these hyaloclastites have planar surfaces compared to those which have concave outer surfaces and vesicular nature, suggesting that these hyaloclastites were produced by a relatively gentle process rather than by explosive magma-water action in an oceanic setting.

4 illus, 1 table, 39 ref

023633   Gujar A R;Ambre N V;Iyer S D;Mislankar P G; Loveson V J (NO, National Institute of Oceanography (CSIR), Dona Paula, Goa-403 004, Email: agujar@nio.org) : Placer chromite along south Maharashtra, central west coast of India. Curr Sci 2010, 99(4), 492-9.

Described here the onshore occurrence of placer chromite, its mineralogy, geochemistry and reserve potential from a 12.5 km stretch (Pirwadi-Talashil) of south Maharashtra coast, India. The sediments in the area are moderately well to very well sorted. The heavy mineral concentration ranges between 0.69% and 98.80% (av. 18.87%), increases from north to south, and comprises of ilmenite, magnetite and chromite, whereas garnet, pyroxene, amphibole, zircon, tourmaline, rutile and staurolite are in minor proportions. The concentration of chromite within the heavy mineral fraction ranges between 0.64% and 12.35%, whereas in the bulk sediment it ranges from 0.05% to 10.90%. The chromite grains are rounded to sub-rounded, marginally altered along their border and are ferro- and magnesio-chromite varieties with 32.06-48.3% Cr₂O₃, FeO + Fe₂O₃ between 23% and 27%, and MgO between 3.31% and 14.86%. The chromite grains have been derived from ultrabasic rocks and chromitites present at the upper reaches of the Gad river. The observed occurrence and variation in the distribution of chromite is due to the differences in the sediment supply from the Achara and Gad rivers, their sorting and associated oceanographic processes. The inferred reserve of chromite is about 0.032 mt.

6 illus, 4 tables, 37 ref

023632   Gopinath G (NO, Centre for Water Resources Development and Management, Kozhikode-673 571, Email: gg@cwrdm.org) : Sediment stratification and bathymetric survey using sediment echo sounder in reservoirs and shallow marine areas. Curr Sci 2010, 99(12), 1821-5.

The sediment echo sounder plays a pivotal role in assessing bathymetry as well as in the stratification of sediments in reservoirs and shallow marine areas. Reservoirs of India are facing reduction in capacity due to siltation process and this can be best quantified using the sediment echo sounder. The importance of this instrument is that it can establish water depths and identify significant sub-seabed reflectors and shallow stratigraphic units. The sediment echo sounder has also proved accurate and expeditious for reservoir desiltation studies as well as in shallow marine areas for developmental activities.

2 illus, 2 tables, 3 ref

023631   Freymueller J T (Geophysical Institute, Alaska Fairbanks Univ, AK 99775, USA, Email: jeff.freymueller@gi.alaska.edu) : Active tectonics of plate boundary zones and the continuity of plate boundary deformation from Asia to North America. Curr Sci 2010, 99(12), 1719-32.

Pervasive fragmentation of continental lithosphere at plate boundaries is the rule, not the exception. However, over most of the plate boundary zones of Asia and western North America, crustal motions observed by geodesy can be described well by models that use a number of rigid plates or blocks, bounded by faults that are presumed to cut the entire lithosphere. Only a few areas, mostly in the Tibetan Plateau, may be exceptions to this rule because they display a more continuum-like deformation pattern. This might result from deformation that is distributed broadly at depth, even if it is mainly localized at the surface. The lithosphere of deforming Asia and North America is fragmented into several large rigid or very slowly straining regions, most likely small plates within the plate boundary zone. Most of these small plates move slowly, making the definition of the plates and their boundaries sometimes controversial. The plate boundary zones of Asia and North America are connected as part of a broad band of distributed deformation that marks the entire northern Pacific Rim. Distributed deformation is continuous or nearly so from Baja California around the north Pacific to Tibet, and beyond. Study of plate boundary zones is complicated by temporal variations in deformation. Despite the time dependence implied by postseismic deformation models, the concept of an interseismic period dominated by steady deformation with time appears to remain valid. Development of an earthquake cycle model that explains both pre- and post-earthquake observations remains an area of active research. In addition, there is some evidence for changes in fault slip rates over time, particularly when pairs of faults within a small area show coupled behaviour.

4 illus, 95 ref

023630   Deka N;Das L;Khan S A (Agricultural Meteorology & Physics Dep, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur-741 252) : Assessing meteorological drought using standardized precipitation index over gangetic West Bengal on its neighborhood. Envir Ecol 2011, 29(4A), 2085-90.

The investigation was carried out over Gangetic West Bengal (GWB) and its neighborhood regions extending from 20 to 26°N and 83 to 89°E to assess meteorological drought using standardized precipi-tation indices (SPI). SPI was calculated for 22 stations by using 32 years (1961-92) of precipitation data. Precipitation data are not normally distributed and hence a transformation to data was first employed to obtain such transferred values as would follow a normal distribution. The study was able to identify the drought sensitive stations, sensitive years, onset of drought and its maximum spatial extent over the study area by analyzing short term (1-2 months), seasonal (3- and 6- month) and long term (1 year or more) SPI values. Results further revealed that 3- month SPI represents a good measure to monitor monsoon season drought conditions, compared to other SPl-time series.

7 illus, 4 ref

023629   Das Sharma S;Ramesh D S (NO, National Geophysical Research Institute (CSIR), Hyderabad-500 007, Email: dassharma@ngri.res.in) : Deep plumes, kimberlites and diamonds- a peep inside the earth through time. Curr Sci 2010, 99(6), 720-2.

3 illus, 18 ref

023628   Das S K;Dobhal D P;Juyal N (NO, National Atmospheric Research Laboratory, Gadanki, Tirupati-517 502, Email: sanatkrdas@gmail.com) : Variability of aerosol optical depth and recent recessional trend in Dokriani glacier, Bhagirathi valley, Garhwal Himalaya. Curr Sci 2010, 99(12), 1816-21.

Temporal changes in aerosol optical depth (AOD) during 2001-2008 obtained from Moderate Resolution Imaging Spectroradiometer oil-board Terra satellite and the glacier recession data of Dokriani glacier in the Bhagirathi valley show a reasonable correlation (R² = 0.86). An increase in AOD was observed after 2005, which coincides with the accelerated recession of the Dokriani glacier. We hypothesize that increased AOD over the Himalayan region led to enhanced aerosol heating, which contributed to the recent observed recessional trend of the glacier. This suggests that AOD can be used to obtain the spatial and temporal changes in microclimatic conditions in the inaccessible glaciated terrain of the Himalayas.

5 illus, 35 ref

023627   Berdnikov N;Balaram V;Cherepanov A;Avdeev D; Konovalova N;Sukharulidze G (NO, Institute of Tectonics and Geophysics FEB RAS, Khabarovsk, Russia, Email: balaram1951@yahoo.com) : Some observations on the determination of platinum group elements and gold in black shales. Curr Sci 2010, 99(4), 518-21.

The concentration levels and distribution features of the platinum group elements (PGE) in black shales with high carbon content from the Bureya Massif, Far East Russia are discussed. This study compares PGE and gold (Au) values in black shale ores from the eastern Bureya Massif. Mineralogical studies using SEM-EDS on PGE-bearing inclusions in black shales reveal that they always contain O and C along with Pt, Pd, Ir and Os. It is believed that PGE are present in the form of organometallic compounds which are extremely resistant to any exposure, including acid dissolution and fire assay procedures. There is a lot of variation in the concentration values obtained using different analytical methods. Observations, problems and possible causes for the erratic and low recoveries of Au and PGE in the highly carbonaceous black shales are discussed.

^ssc2 illus, 1 table, 13 ref

023626   Basu B K;Bhagyalakshmi K (Flosolver Unit, CSIR, National Aerospace Laboratories, Bangalore-560 017, Email: bkbasu1948@yahoo.co.in) : Forecast of the track and intensity of the tropical cyclone AILA over the Bay of Bengal by the global spectral atmospheric model VARSHA. Curr Sci 2010, 99(6), 765-74.

The tropical cyclone 'AILA' formed over the Bay of Bengal and crossed the West Bengal coast in the afternoon of 25 May 2009. The track, surface pressure distribution, asymmetric wind, warm core, etc. and special features like rapid intensification near the coast and retention of intensity after landfall are examined in the forecast of model VARSHA. This model predicted the rapid intensification and sustained intensity after landfall indicating interaction with a cold core trough in the westerly. Comparison with observations by IMD and also the FNL analysis of NCEP, USA shows that VARSHA performed well in predicting the structure, motion and intensification of AILA.

9 illus, 2 tables, 24 ref

023625   Baruah S;Hazarika D;Kalita A;Goswami S (Geoscience Div, CSIR, North-East Institute of Science and Technology (formerly Regional Research Laboratory), Jorhat-785 006, Email: saurabhb_23@yahoo.com) : Intrinsic and scattering attenuation in chedrang fault and its vicinity-the rupture area of great Assam earthquake of 12 june 1897 (M=8.7). Curr Sci 2010, 99(6), 775-84.

The attenuation of seismic waves is one of the basic physical parameters used in seismological studies, which is closely related to the seismicity and tectonic activity of a particular area. In the present study, attenuation properties of the crust beneath the Chedrang Fault and its vicinity, the rupture area of the great Assam earthquake of 12 June 1897 (M= 8.7) are studied using waveforms recorded by a local seismic network composed of five stations. In total 20 local earthquakes have been analysed to estimate (i) coda wave attenuation quality factor (Q_c) applying single scattering model, (ii) total attenuation quality factor (Q_d) from direct S-wave applying spectral ratio method and (Hi) intrinsic and scattering attenuation quality factors (Q_i and Q_s) following the Wennerberg's approach. Coda Q (2c) values are obtained using different coda window lengths (20, 30 and 40 s) for frequency bands centred at 1, 1.5, 2, 3, 4, 6, 8, 12, 16 and 18 Hz. This study indicates that Q_c increases with increasing lapse time and that Q_c is frequency dependent following the attenuation-frequency relation Q_c(20)= 36.29 ±1.18f^1.4±0.09 Q_c(30)= 69.92 ± 1.11f^1.23±0.46 and Q_c(40)117.08±1.08f^{1.07±0.05 for 20, 30 and 40 s respectively. This behaviour is usually correlated to the presence of heterogeneity in the crust and to the degree of tectonic complexity underneath the study area. The Q-1_c values for this area follow as substantially similar trend of Q-1_c decay with frequency as the other tectonically active regions of the world. Finally, from the separation of Q_s and Q_i values, it is observed that the study area can be characterized by a low scattering attenuation (small scattering Q inverse, Q-1_s and by a relatively high intrinsic attenuation (high intrinsic Q inverse, Q-1_i.}