021625   Sharma A;Saikia A;Khare P;Dutta D K;Baruah B P (Coal Chemistry Div, CSIR-North East Institute of Science & Technology, Jorhat-785 006, Email: bpbaruah@yahoo.com) : The chemical composition of tertiary Indian coal ash and its combustion behaviour - a statistical approach: Part 2. J Earth Syst Sci 2014, 123(6), 1438-49.

In Part 1 of the present investigation, 37 representative Eocene coal samples of Meghalaya, India were analyzed and their physico-chemical characteristics and the major oxides and minerals present in ash samples were studied for assessing the genesis of these coals. Various statistical tools were also applied to study their genesis. The datasets from Part 1 used in this investigation (Part 2) show the contribution of major oxides towards ash fusion temperatures (AFTs). The regression analysis of high temperature ash (HTA) composition and initial deformation temperature (IDT) show a definite increasing or decreasing trend, which has been used to determine the predictive indices for slagging, fouling, and abrasion propensities during combustion practices. The increase or decrease of IDT is influenced by the increase of Fe₂O₃, Al₂O₃, SiO₂, and CaO, respectively. Detrital-authigenic index (DAI) calculated from the ash composition and its relation with AFT indicates Sialoferric nature of these coals. The correlation analysis, Principal Component Analysis (PCA), and Hierarchical Cluster Analysis (HCA) were used to study the possible fouling, slagging, and abrasion potentials in boilers during the coal combustion processes. A positive relationship between slagging and heating values of the coal has been found in this study.

5 illus, 6 tables, 41 ref

021624   Sengupta P K (NO, , , Email: sengupta_pradip@yahoo.com) : The chronicle of arsenic. Sci Cult 2015, 81(1-2), 38-40.

5 illus

021623   Sahu S;Saha D (Central Ground Water Board, , Mid-eastern Region, 6th and 7th floor, Lok Nayak Jai Prakash Bhawan, Fraser Road, Patna-800 001, Email: sudarsan_cgwb@yahoo.co.in) : Geomorphologic, stratigraphic and sedimentologic evidences of tectonic activity in Sone-Ganga alluvial tract in Middle Ganga Plain, India. J Earth Syst Sci 2014, 123(6), 1335-47.

Basement of the Ganga basin in the Himalayan foreland is criss-crossed by several faults, dividing the basin into several sub-blocks forming horsts, grabens, or half-grabens. Tectonic perturbations along basement faults have affected the fluvial regime and extent of sediment fill in different parts of the basin during Late Quaternary. The East Patna Fault (EPF) and the West Patna Fault (WPF), located in Sone-Ganga alluvial tract in the southern marginal parts of Middle Ganga Plain (MGP), have remained tectonically active. The EPF particularly has acted significantly and influenced in evolving the geomorphological landscape and the stratigraphic architecture of the area. The block bounded by the two faults has earlier been considered as a single entity, constituting a half-graben. The present investigation (by morpho-stratigraphic and sedimentologic means) has revealed the existence of yet another fault within the half-graben, referred to as Bishunpur-Khagaul Fault (BKF). Many of the long profile morphological characters (e.g., knick-zone, low width-depth ratio) of the Sone River at its lower reaches can be ascribed to local structural deformation along BKF. These basement faults in MGP lie parallel to each other in NE-SW direction.

9 illus, 66 ref

021622   Sahajpal S;Sircar A;Singh A;VaidyaD;Shah M; Dhale S (School of Petroleum Technology, Pandit Deendayal Petroleum University, Gandhinagar, Gujarat) : Geothermal exploration in Gujarat. Int J latest Technol Engng Mgmt appl Sci 2015, 4(5), 38-47.

The present study emphasises the importance of geothermal exploration in Gujarat using integrated geological and geophysical techniques. A case example from Unai (20° 51' N and 73° 24' E) is presented here, which is a potential geothermal site identified by the authors of this paper. The proximal hinterlands juxtaposed to linear quaternary basins with fault bounded contacts, have anomalous crustal structure with high density mantle derived bodies. This is emplaced at shallow crustal levels reflecting high gravity anomalies. The hinterland domain is further characterized by high heat flow with thermal spring (54°C temperature). The Magnetotelluric Survey carried out in this region suggests intense hydro-technical activity. This renders the area prone to geothermal activity warranting multi-disciplinary evaluation. Geochemical sampling of thermal spring water was carried out, which shows low level of carbonate and bi-carbonate component in water samples. It suggests that source of water is deep seated under the trapean flows. Attempts are made to connect shallow and deep reservoirs and a unified fluid flow model has been presented.

16 illus, 13 ref

021621   Sagarika Chandra;Dwivedi A K;Manoj Kumar (Centre of Excellence in Climatology, Birla Institute of Technology, Misra, Ranchi-835 215, Email: akdwivedi30@yahoo.com) : Characterization of the atmospheric boundary layer from radiosonde observations along eastern end of monsoon trough of India. J Earth Syst Sci 2014, 123(6), 1233-40.

A comparison of two methods for the calculation of the height of atmospheric boundary layer (ABL), using balloon-borne GPS radiosonde data is presented. ABL has been characterized using vertical profiles of meteorological parameter. The gradient of virtual potential temperature (θ_v) profile for the determination of mixed layer heights (MLH) and the mean value of turbulent flow depth (TFD) obtained from the vertical profile of Bulk Richardson Number (R_iB) have been used in this study. One-year data have been used for the study. There is large seasonal variability in MLH with a peak in the summer and winter whereas the TFD remained steady throughout the year. Results from the present study indicate that the magnitudes of TFD are often larger than the MLH.

6 illus, 2 tables, 15 ref

021620   Roxy M S;Sumithranand V B;Renuka G (Physics Dep, Sree Narayana College, Kollam-691 001, Email: roxyms@gmail.com) : Estimation of soil moisture and its effect on soil thermal characteristics at astronomical observatory, Thiruvananthapuram, South Kerala. J Earth Syst Sci 2014, 123(8), 1793-1807.

Soil moisture is an important parameter of the earth's climate system. Regression model for estimation of oil moisture at various depths has been developed using the amount of moisture near the surface layer. The estimated values of soil moisture are tested with the measured moisture values and it is found that the estimations are comparable with the observations. The variation of soil thermal properties with the amount of moisture in isohyperthermic ultisols has been investigated at a tropical site in south Kerala for the year 2008. The soil temperatures at 0.05, 0.10, 0.20, 0.30, and 0.50 m depths and soil moisture at 0.05 and 0.10 m are measured using the hydrometeorological data acquisition system installed at the observational site. For soil water contents ranging between 11 and 42% in the soil layer of depth 0.05-0.10 m, the mean values of the heat capacity, thermal diffusivity, thermal conductivity, and thermal admittance obtained were 2.2466 x 10^{-6 Jm-3K-1, 0.4238 x 10-6 m2s-1, 0.9658 Wm-1K-1, 2.1517 Jm-2s-1/2K-1, respectively. The magnitudes of the diurnal soil thermal parameters showed strong ociation with the levels of the water content. The thermal diffusivity was found to increase with the amount of soil moisture, up to about 22 of the volumetric water content, but fell as the water content further increases. Similar patterns of the soil moisture levels were noticeable both for the thermal conductivity and admittance.}

12 illus, 29 ref

021619   Renner R M;Nath B N;Glasby G P (School of Mathematics, Statistics and Operations Research, Victoria University of Wellington, Wellington, New Zealand, Email: ross.renner@msor.vuw.ac.nz ) : An appraisal of an iterative construction of the endmembers controlling the composition of deep-sea manganese nodules from the Central Indian Ocean Basin. J Earth Syst Sci 2014, 123(6), 1399-411.

This paper describes an estimation of endmember compositions followed by the assessment of those results by log-ratio variance analysis. As an appraisal, it deals only with the first objective of an endmember analysis namely, to identify endmembers if they exist by estimating their compositions. Following the creation of the endmember estimates, the computation of an array of log-ratio variances was a key innovation in this type of study. Log-ratio variances revealed intrinsic linear associations between the dominant elements on each of the estimated endmember compositions, largely confirming the endmember analysis. The dataset under study contained the concentrations of 16 elements in 93 samples of deep-sea manganese nodules from the Central Indian Ocean Basin. Many previous analyses of these nodules were undertaken to assess the economic potential of the deposits. This study by contrast, quantified the inter-element associations that account for the nodule compositions. Four endmembers were identified. The elements loaded on each were: (1) Mn, Zn, Ni, Cu, Mn-rich, (2) Fe, Ti, P, Co, Fe-rich, (3) Si, Al, Na, K, clay minerals, (3) Mg, ultramafic material, possibly including Mn, Cr, V, Ca, Na. These latter elements were also detected by their log-ratio variances to be associated with Mg on the 4th endmember.

3 tables, 35 ref

021618   Rastogi R G;Chandra H;Janardhan P;Hoang T L; Condori L;Pant T K;Prasad D S V V D;Reinisch B (Physical Research Laboratory, , Ahmedabad-380 009, Email: hchandra@prl.res.in) : Spread-F during the magnetic storm of 22 January 2004 at low latitudes: Effect of IMF-Bz in relation to local sunset time. J Earth Syst Sci 2014, 123(6), 1273-85.

The paper describes the results of spread-F at low latitude stations around the world during the magnetic storm starting at 0130 UT on 22 January 2004. The storm can be divided into two phases, first phase up to 1000 UT when interplanetary magnetic field IMF-Bz was highly fluctuating around a small positive value and the second phase after a sudden large southward turning of IMF-Bz at 1030 UT. The first phase produced strong spread-F at Jicamarca, Sao Luis, and Ascension Island and caused complete inhibition of spread-F at Thumba and Waltair in India. It generated weak spread-F at Ho Chi Minh City in Vietnam and strong spread-F at Hainan and Chung Li. The strong spread-F at Hainan and Chung Li were caused by the positive IMF-Bz during the first phase of the storm and not by the negative pulse of IMF-Bz at 1000 UT.

15 illus, 1 table, 24 ref

021617   Rao V K;Narayana A C (Centre for Earth and Space Science, University of Hyderabad, Hyderabad-500 046, Email: vkrao@nmdc.co.in) : Application of nonlinear geostatistical indicator kriging in lithological categorization of an iron ore deposit. Curr Sci 2015, 108(3), 413-21.

Nonlinear geostatistics is commonly used in ore grade estimation and seldom used in lithological characterization. Categorization of lithological units is essential in ore grade estimation, and this can be done based on the lithological information obtained from drill-hole data. In general, a conventional classification method was used to delineate different lithological units using geological cross-sections derived from borehole logs. In this study, e-suggest an approach based on geostatistical nonlinear indicator kriging (IK) to delineate' different lithological units of an iron ore deposit. Iron ore has been broadly grouped into eight litho units based on physical and chemical characteristics of the core samples recovered from drill holes during ration stage. IK helps in the construction of litho maps for different benches of the mining deposit. Fe grades were estimated using ordinary kriging model and grade maps were prepared for all the benches of the deposit. A comparison was done between the grades of each litho type resulting from the two methods, Le. IK model and geological cross-sectional model and the relative merits of the IK approach have also briefly discussed.

10 illus, 5 tables, 19 ref

021616   Rao C S;Majumder M;Roy J;Chaudhari M S; Ramteke R S (Geophyiscs Division, Central Water and Power Research Station, Khadakwasla R S, Email: chilukuri3_2000@yahoo.com) : Delineating coal seams and establishing water tightness by electrical resistivity imaging. Curr Sci 2015, 108(3), 427-34.

In the present study, continuity of coal seams was established in the area adjacent to the existing open cast coal mine at Talabira, Odisha situated close to Hirakud reservoir. Water tightness of the strata in the zone between the reservoir and the mine needs to be verified to prevent inundation by subterranean seepage and ensure safety. Multi electrode resistivity imaging technique was used to establish continuity of coal seams and verify water tightness. From the studies conducted in and around the mine along 13 profiles, coal seams with relatively high resistivity ranging from 500 to 1500 Ohm-m at depths varying from 10 to 31 m were delineated. The intervening strata between the reservoir and the open cast mine was found to be fairly tight without any significant zone susceptible to seepage.

10 illus, 1 table, 30 ref

021615   Putty M R Y;Thipperudrappa N M;Chandramouli P N (NO, The National Institut of Engineering, Mysore-570 008, Email: puttyyadupahi@gmail.com) : Hydrological feasibility of gravity diversion of the west flowing Nethravathi in Karnataka. J Earth Syst Sci 2014, 123(8), 1781-92.

Concept of collecting surface runoff on the slopes in canals cut across the western slopes of the Western Ghats, in order to divert part of a flow in the west flowing rivers to the east by gravity, is promoted in Karnataka. This paper presents a study of the hydrological feasibility of such canals, termed 'garland canals' and claimed to be an environmental friendly alternative to the conventional technologies for inter-basin transfer of water, by their promoters. The paper presents a methodology for disaggregating normal annual rainfall into 15-min magnitudes and its application for simulating surface off using a knowledge of infiltration rates on the slopes. The study has been carried out considering part of a garland canal proposed for diverting the river Netravathi in the state. The results from the study reveal that significant amounts of flow can be collected in the proposed canal only if streams are also tapped and that because of the arrangements necessary for the purpose, garland canals cannot be considered a means superior to the conventional methods for diverting west flowing rivers.

9 illus, 6 tables, 18 ref

021614   Murthy S;Tripathi A;Chakraborti B;Singh U P (NO, Birbal Sahni Institute of Palaeobotany, Lucknow-226 007, Email: srikanta_murthy22@rediffmail.com) : Palynostratigraphy of permian succession from Binja blck, South Karanpura coalfield, Jharkhand, India. J Earth Syst Sci 2014, 123(8), 1895-906.

Palynological investigations are carried out on approximately 538.00-m thick Gondwana strata from borehole SKB-1, Binja Block, South Karanpura Coalfield in Jharkhand. Based on the distribution pattern of age marker palynotaxa, two distinct palynoassemblages are identified. Palynoassemblage-I in the lithologically designated Barren Measures and Barakar formations, between 552.00 and 53.20 m depth show dominance of striate bisaccate (Striatopodocarpites, Crescentipollenites, and Faunipollenites) and abundance of nonstriate bisaccate (Scheuringipollenites). Upward the Palynoassemblage-II (39.50-13.80 ill depth) is rich in striate bisaccate (Striatopodocarpites and Crescentipollenites) and significant envelopping monosaccate Densipollenites magnicorpus pollen. These strata have been equated with Raniganj Formation of Latest Permian age. The First Appearance Datum (FAD) of Arcuatipollenites pellucidus, Playfordiaspora cancellosa, Alisporites sp., Falcisporites sp. and K rempipollenites indicus observed at 13.80 and 39.50 m depth, mark the transition of Permian into the Lower Triassic. The FADs of Guttulapollenites spp. at 49.10 and 504.70 m, Goubinispora morondavensis at 415.90 m, Alisporites ovalis and Arcuatipollenites sp. at 526.70 m is observed and suggest that these sediments are equivalent to Raniganj Formation, Late Permian in age.

3 illus, 6 tables, 12 ref

021613   Mukherjee A et al (NO, CSIR-National Institute of Oceanography (CSIR-NIO), Dona Paula, Goa-403 004, Email: shankar@nio.org) : Observed seasonal and intraseasonal variability of the East India Coastal Current on the continental slope. J Earth Syst Sci 2014, 123(6), 1197-232.

We present data from three acoustic Doppler current profilers (ADCPs) moored off Cuddalore (12°N), Kakinada (16.5°N), and Gopalpur (19°N) on the continental slope of the western Bay of Bengal and one mooring on the slope of the northern bay (89°E, 19°N; referred to as being located at Paradip). The data were collected during May 2009 to March 2013 and the observations show that the seasonal cycle, which includes the annual cycle, the semi-annual cycle, and a peak around 120 days, dominates the observed variability of the East India Coastal Current (EICC). Spectral analysis suggests that the 120-day peak dominates the seasonal variability at Paradip and is strong at Gopalpur and Kakinada. The annual cycle is coherent along the western boundary of the bay, i.e., the east coast of India, but with significant phase differences between moorings. At the semi-annual and 120-day periods, the alongshore coherence is weaker. Intraseasonal variability is weaker than the seasonal cycle, particularly at Cuddalore and Paradip, and it exhibits seasonality: the strongest intraseasonal variation is during spring (February-April). Peaks around 12 and 20-22 days are also seen at Gopalpur, Kakinada, and Cuddalore. A striking feature of the currents is the upward phase propagation, but there are also instances when phase propagates downward. The much lower vertical phase speed in the top ~100 m at Cuddalore leads to a distinct undercurrent at this location; at other locations, the undercurrent, though it exists often, is not as striking. During spring, however, the EICC tends to flow poleward (eastward) at Cuddalore, Kakinada, and Gopalpur (Paradip) over the top ~300 m, which is the maximum depth to which observations were made. The cross-shore component of the EICC is much weaker than the alongshore component at Cuddalore and, except for a few bursts during spring, at Kakinada and Gopalpur. It is only at Paradip, on the slope of the northern boundary, that significant cross-shore flows are seen during spring and the summer monsoon (June-August) and these flows are seen to be associated with eddy-like circulations in the altimeter data. We use the ADCP data to validate popular current data products like OSCAR (Ocean Surface Currents Analyses Real-time), ECCO2 (Estimating the Circulation and Climate of the Ocean, Phase II), and GODAS (Global Ocean Data Assimilation System). The OSCAR currents at Paradip match the observed currents well, but the correlation is much weaker at the other three locations. Both ECCO2 and GODAS fair poorly, particularly the latter because its variability in this boundary-current regime is extremely weak. Though it performs badly at Paradip, ECCO2 does capture the observed variability on occasions at the other locations.

24 illus, 4 tables, 135 ref

021612   Mishra R;andey D K;Ramesh P;Shipboard Scientific Party SK-306 (National Centre for Antarctic and Ocean Research, (Ministry of Earth S, , Headland Sada, Vasco-Da-Gama, Goa-403 804, Email: ravimishrancaor.gov.in) : Active channel systems in the middle Indus fan: results from high-resolution bathymetry surveys. Curr Sci 2015, 108(3), 409-12.

Multibeam swath bathymetry survey was carried out in the middle Indus fan region in the eastern Arabian Sea. Using high-resolution bathymetry data, major morphological features such as the Raman seamount and the Laxmi ridge have been mapped. This study also reveals the presence of sinuous channel systems, continuing towards the distal fan. Though there are several reports on the presence of channels in different regions of the Indus fan, we report here the presence of active channels to the east of the Laxmi ridge. The total length of all channels along the channel axis is about 915 km. The individual spreads of the channels vary from 189.8 to 1980.5 m. Most of the channels are shallow with the average depth measuring about 60 m. The longest channel is about 256.3 km long, 702 m wide and about 57 m deep. The channels observed are similar to the land-based fluvial channels. The channels identified are highly sinuous in nature, their meanders and cut-off meanders are similar to the characteristics of fluvial channels. In general, average channel course in the study area is more than twice the straight course.

5 illus, 1 table, 17 ref

021611   Miguel R R;Malte S (University Pablo de Olavide, , Seville, Spain, Email: mrodrod@upo.es) : Hydrological simulation of the water regime in two Playa lakes located in Southern Spain. J Earth Syst Sci 2014, 123(6), 1295-305.

Subject of this paper is the detailed hydrological simulation of two playa lakes located in southern Spain from January 2011 to March 2012 on a daily basis. These playas are placed over a 400-km^{2 shallow aquifer, which is exposed to an increasing stress caused by agricultural activities, mainly olive grove plantations. The objective of the paper is to elaborate a detailed numeric model that simulates the water regime of each playa lake on a daily scale. The simulation is compared to measured water level (WL) data of the playas in order to characterize the groundwater-surface interactions. The ultimate objective of this paper is to assess the environmental impact of the increasing anthropogenic water consumption within the area of research. The results of the GW-surface interaction were very consistent with previous works. One of the playa lakes is groundwater-dependent and the other one is presumably a perched playa lake. The GW discharge of the former playa (214 mm) during the research period stands in sharp contrast to no regional GW discharge in the latter. Water level data prove that the hydrological year (2011-2012) had a very negative water budget. The evapotranspiration estimation was almost as high as double the sum of the precipitation, the run-off, and the groundwater discharge. The simulation of an anthropologically altered water regime proves that water retrieval has a harmful impact on the WL of the playa lakes as well as on the aquifer.}

8 illus, 3 tables, 13 ref

021610   Miglani R;Shahrukh M;Israil M;GuptaP K; Varshney S K;Elena S (NO, Indian Institute of technology Roorkee, Roorkee 247 667, Email: mohammad.israil@gmail.com) : Geoelectric structure estimated from magnetotelluric data from the Uttarakhand Himalaya, India. J Earth Syst Sci 2014, 123(8), 1907-18.

Geoelectric strike and resistivity structure of the crust have been estimated from 37 magnetotelluric (MT) data sites along a profile from Roorkee to Gangotri in Uttarakhand Himalaya. Impedance decomposition schemes based on Bahr's, Groom Bailey and Phase tensor were implemented in a MATLAB code for the average strike estimation. Geoelectric strike direction varies with period as well as in different lithootectonic units along the profile. In the period band from 1 to 100 s average geoelectric strike in the southern end of the profile (Indo-Gangetic Plains) is N79°W, which is slightly rotated to the north in the Lesser Himalayan region and becomes N68°W whereas it is N81°W in the Higher Himalayan region. However, average strike is stabilized to N77°W for the entire profile in the long period band (100-1000s). Geoelectrical structure of the crust has been obtained along the profile by 2D inversion of MT data. Major features of 2D resistivity model are: (i) southern part of the model is a low resistivity (<60>50 Ωm) zone at shallow depth (5-7 km) representing the loose sediments of the Indo-Gangetic' Plains (IGP), whose thickness increases in the south; (ii) highly resistive (<62>1000 Ωm) layer below the IGP sediments is the basement rock, representing the resistivity of the top of the subducting Indian Plate; (iii) the Main Boundary Thrust (MBT) and the Main Central Thrust (MCT) zones can be seen in the electrical image. However, the Himalayan Frontal Thrust (HFT) could not be resolved and (iv) a low resistivity <60>10 Ωm) feature in the MCT zone extending to the depth of 30 km is delineated. This low resistivity could be due to fluid-filled fractured rock matrix or partial melt zone. Hypocenters of many earthquakes are concentrated along the boundary of this low resistivity zone and relatively high resistivity blocks around it. The resulted model supports flat-ramp-flat geometry of the Main Himalayan Thrust along which the Indian Plate is subducting.

7 illus, 1 table, 39 ref

021609   Loveson V J;Gujar A R;Barnwal R;Khare R; Rajamanickam G V (CSIR-Central Institute of Mining and Fuel Research, , Dhanbad-826 001, Email: vjloveson@yahoo.co.uk) : GPR studies over the tsunami affected Karaikal beach, Tamil Nadu, south India. J Earth Syst Sci 2014, 123(6), 1375-85.

In this study, results of GPR profiling related to mapping of subsurface sedimentary layers at tsunami affected Karaikal beach are presented . A 400 MHz antenna was used for profiling along 262 m stretch of transect from beach to backshore areas with penetration of about 2.0 m depth (50 ns two-way travel time). The velocity analysis was carried out to estimate the depth information along the GPR profile. Based on the significant changes in the reflection amplitude, three different zones are marked and the upper zone is noticed with less moisture compared to other two (saturated) zones. The water table is noticed to vary from 0.5 to 0.75 m depth (12-15 ns) as moving away from the coastline. Buried erosional surface is observed at 1.5 m depth (40-42 ns), which represents the limit up to which the extreme event acted upon. In other words, it is the depth to which the tsunami sediments have been piled up to about 1.5 m thickness. Three field test pits were made along the transect and sedimentary sequences were recorded. The sand layers, especially, heavy mineral layers, recorded in the test pits indicate a positive correlation with the amplitude and velocity changes in the GPR profile. Such interpretation seems to be difficult in the middle zone due to its water saturation condition. But it is fairly clear in the lower zone located just below the erosional surface where the strata is comparatively more compact. The inferences from the GPR profile thus provide a lucid insight to the subsurface sediment sequences of the tsunami sediments in the Karaikal beach.

9 illus, 24 ref

021608   Joshi J C;Srivastava (Snow and Avalanche Study Establishment, , Him-Parisar, Sector 37-A, Chandigarh, Email: joshjagdish@gmail.com) : Hiddn markov model for avalanche forecasting on Chowkibal-Tangdhar road axis in Indian Himalayas. J Earth Syst Sci 2014, 123(8), 1771-9.

Numerical avalanche prediction scheme using Hidden Markov Model (HMM) has been developed for Chowkibal-Tangdhar road axis in J&K, India. The model forecast is in the form of different levels of avalanche danger (no, low, medium, and high) with a lead time of two days. Snow and meteorological data (maximum temperature, minimum temperature, fresh snow, fresh snow duration, standing snow) of past 12 winters (1992-2008) have been used to derive the model input variables (average temperature, fresh snow in 24 hrs, snow fall intensity, standing snow, Snow Temperature Index (STI) of the top layer, and STI of buried layer). As in HMMs, there are two sequences: a state sequence and a state dependent observation sequence; in the present model, different levels of avalanche danger are considered as different states of the model and Avalanche Activity Index (AAI) of a day, derived from the model input variables, as an observation. Validation of the model with independent data of two winters (2008-2009, 2009-201O) gives 80% accuracy for both day-1 and day-2. Comparison of various forecasting quality rneasures and Heidke Skill Score of the HMM and the NN model indicate better forecasting skill of the HMM.

1 illus, 7 tables, 22 ref

021607   John M;Jena B K;Sivakholundu K M (NO, National Institute of Ocean Technology, Ministry of Earth Science, Chennai-600 100, Email: bkjena@niot.res.in) : Surface current and wave measurement during cyclone Phailin by high frequecy radars along the Indian coast. Curr Sci 2015, 108(3), 405-9.

Cyclone Phailin originated in the east central Bay of Bengal (BoB) and crossed into the Indian mainland after traversing through the BoB. High frequency radar (HFR) operated by the National Institute of Ocean Technology could track the surface currents and high wave activity within its measuring limits. The radar data provide valuable information on the surface dynamics during the cyclone period. The HFR observations compare well with those of wave rider buoy. This opens up opportunities for observing the wave conditions during the cyclonic period over longer distances from the shore. This method is relatively more robust as HFR is less likely to be disrupted due to the passage of cyclones, unlike moored systems.

7 illus, 12 re

021606   Jindal P;Thapliyal P K;Shukla M V;Mishra A K; Mitra D (NO, Indian Institute of Remote Sensing, Dehradun-248 001, Email: pooja_j@iirs.gov.in) : Total column ozone retrieval using INSAT-3D sounder in the tropics: A simulation study. J Earth Syst Sci 2014, 123(6), 1265-71.

The study examines the potential of infrared sounder observations from Indian geostationary satellite INSAT-3D for the estimation of total column integrated ozone over the tropical Indian region. A dataset with diverse profiles was used to create training and testing datasets using forward simulations from a radiative transfer model for infrared sounder channels. A study was carried out for the standard tropical atmospheric profile to examine the sensitivity of ozone band radiance corresponding to the atmospheric temperature, water vapour, and ozone mixing ratios at different atmospheric pressure levels. Further, statistical retrieval technique has been used for the total column ozone estimation using two different approaches: (i) ozone channel observation along with the a-priori estimate of temperature and water vapour profile and (ii) only sounder channels observations. The accuracy of the retrieval algorithms was examined for different errors in the atmospheric profiles for the method (i) and different sensor noise specification for the method (ii). This study has shown that accurate temperature information is very important for ozone estimation and lower instrument noise results in better ozone estimates.

1 illus, 5 tables, 22 ref

021605   Hou S;Wang P;Guo Y;Li T (NO, Yellow River Institute of Hydraulic Research, YRCC, Zhengzhou-450 003, China, Email: wp_sc@sina.com) : Response of bankfull discharge of the Inner Mongolia Yellow River to flow and sediment factors. J Earth Syst Sci 2014, 123(6), 1307-16.

Bankfull discharge is a comprehensive factor reflecting the channel-forming capability of water flow and the flood and sediment transport capacity of a river channel. It is based on the interaction of the flow, sediment, and river channel, of which flow and sediment conditions play crucial roles. Using data recorded since the 1950s, this paper analyses statistically, the characteristics and variations of bankfull discharge at two stations on the Inner Mongolian reaches of the upper Yellow River. Results indicate that flood season variations in bankfull discharge are nonlinear and are governed by flood peak discharge, mean discharge, and the mean incoming sediment coefficients. Variation in bankfull discharge is related not only to the flow and sediment conditions of the current year but also to those of previous years. The 10-year moving average of flow and sediment conditions can be representative of present and previous years. By considering flood season peak discharge and incoming sediment coefficients as independent impact factors, a formula is derived to determine bankfull discharge. The results can be used to predict the bankfull discharge of the Yellow River channel in Inner Mongolia under specific flow and sediment conditions and provide reference for the purpose of further study related to restoring and maintaining the basic functions of the river channel regarding flood discharge and sediments.

10 illus, 3 tables, 45 ref

021604   Gokhale R;Sohoni M (Computer Science and Engineering Dep, Indian Institute of Technology Bombay, Mumbai-400 076, Email: rahulbg@cse.iitb.ac.in) : Detecting appropriate groundwater-level trends for safe groundwater development. Curr Sci 2015, 108(3), 395-404.

Computation of long-term linear trends of pre- and post-monsoon groundwater (GW) levels is important for the periodic categorization of regions in India according to their GW safety. For this purpose, a specific procedure has been recommended by the Groundwater Estimation Committee, 1997 (GEC'97), constituted by the Government of India. The present article points out the limitations of this procedure by providing statistical evidence from the long-term dataset in the case of Maharashtra. An improved method, having the same data requirements as the GEC'97 method and based on statistically significant recent linear trends is proposed as an alternative. Its suitability for administrative actions is demonstrated on the Maharashtra dataset. We specifically note the spatial patterns in recent linear trends obtained from our algorithm, which are otherwise difficult to detect.

7 illus, 8 tables, 12 ref

021603   Ghani A A etal (Geology Dep, University of Malaya, 50603, Kuala Lumpur, Malaysia, Email: azmangeo@yahoo.com) : Permian ultrafelsic A-type granite from Besar Islands group, Johor, peninsular Malaysia. J Earth Syst Sci 2014, 123(8), 1857-78.

Granitic rocks of the peninsula have traditionally been divided into two provinces, i.e., Western d Eastern provinces, corresponding to S- and I-type granite respectively. The Western Province granitic is characterised by megacrystic and coarse-grained biotite, tin-mineralised, continental collinsion granite, whereas, the Eastern Province granite is bimodal I-type dominated by granodiorite and assotiated gabbroic of arc type granite. This paper reports the occurrence of an A-type granite from peninsular Malaysia. The rocks occur in the Besar, Tengah, and Hujung islands located in the southern part of the peninsula. The granite is highly felsic -with SiO₂ ranging from 75.70% to 77.90%(differentiation index = 94.2-97.04). It is weakly peraluminous (average ACNK=1.02), has normative hypersthene (0.09-2.19%) and high alkali content (8.32-8.60%). The granites have many A-type characteristics, among them are shallow level of emplacement, high Ga, Fe_r/MgO and low P, Sr, Ti, CaO and Nb. Calculated zircon saturation temperatures for the Besar magma ranging from 793° to 806°C is consistent with high temperature partial melting of a felsic infracrustal source which is taken as one of the mechanisms to produce A-type magma. The occurrence of the A-type granite can be related to the extensional back arc basin in the Indo-China terrane during the earliest P rmian.

17 illus, 2 tables, 73 ref

021602   Duggal V;Asha Rani;Mehra R (Applied Sciences Dep, Punjab Technical University, Jalandhar-144 601, Email: vikasduggal86@yahoo.in) : Measurement of soil-gas radon in some areas of Northern Rajasthan, India. J Earth Syst Sci 2014, 123(6), 1241-7.

The health hazards of the radioactive gas radon on general public are well known. In order to understand the level and distribution of ^{222Rn concentrations in soil-gas in Sri Ganganagar district of Rajasthan, a 222Rn survey was carried out for the first time using RAD7, an electronic radon detector manufactured by Durridge Company (USA), at different locations covering a total area of 10,978 km2, having a population of approximately 20 lakh. The measurement of 222Rn concentration in soil-gas was carried out at four different depths (10, 40, 70, and 100 cm). The radon concentration in soil-gas for 10, 40, 70, and 100 cm depths ranged from 0.09-4.25, 0.15-6.30, 0.50-9.18, and 0.72-10.40 kBq m-3, respectively. The minimum value of radon concentration is observed in 33 GB village at 10 cm depth and maximum for Mohanpura village at 100 cm depth. As expected, our data show an increase of soil-gas radon concentration levels with depth. The present results are compared with the available radon data from other studies.}

3 illus, 2 tables, 27 ref

021601   Desai B G;Saklani R D (School of Petroleum Technology, Pandit Deendayal Petroleum University, Raisan Village, Gandhinagar-382 007, Email: bhawanigd@gmail.com) : Ichnofabric analysis of the Tithonian shallow marine sediments (Bhadasar Formation) Jaisalmer Basin, India. J Earth Syst Sci 2014, 123(6), 1413-31.

The shallow marine sedimentary sequence of the Jaisalmer Basin exhibits one of the important and well-developed Tithonian sedimentary outcrops for western India. The ichnology and ichnofabric of the lower part of Bhadasar Formation (i.e., Kolar Dongar Member) belonging to Tithonian age are presented and discussed. The Kolar Dongar Member represents a shallow marine succession that contains 16 ichnotaxa: Ancorichnus ancorichnus, Conichnus conicus, Gyrochorte comosa, cf. Jamesonichnites heinbergi, Imponoglyphus kevadiensis, Laevicyclus mongraensis, Monocraterion tentaculatum, Ophiomorpha nodosa, Palaeophycus tubularis, P. bolbiterminus, Phycodes palmatus, Planolites beverleyensis, Rhizocorallium isp., Rosselia rotatus, R. socialis, and Teichichnus rectus. The ichnofabric analysis divulges five distinct ichnofabrics, each typifying distinct depositional environment within shallow marine conditions. The ichnofabric Ophiomorpha 1 with syn-sedimentary faulting exemplifies high energy conditions typical of lower shoreface environment, whereas the Ophiomorpha 2 ichnofabric typifies upper shoreface environment. The Ancorichnus ichnofabric reflects lower offshore condition of deposition. The high ichnodiversity Ancorichnus-Rosselia ichnofabric is indicative of inner shelf conditions, while low ichno-diversity Teichichnus ichnofabric indicates prevalence of low energy brackish bay environment. Thus, Tithonian Kolar Dongar Member indicates depositional environment ranging from shoreface to offshore to inner shelf and finally to brackish bay environment.

6 illus, 3 tables, 83 ref

021600   Das P P;Sahoo H (Geology Dep, Utkal University, Bhubaneswar, Odisha) : Designing representative groundwater sampling of Mahakalapara block, Odisha: a comprehensive hydro-geologic analysis by GIS approach. Int J latest Technol Engng Mgmt appl Sci 2014, 3(10), 63-8.

Representative groundwater sampling points to the approximation of subsurface aquifer systems cardinally with respect to identifying and monitoring the extent of human or natural contamination. The present study takes into account the hydrological, topographical and geological setting of the area of interest in establishing the sampling locations. Besides these natural influencing factors, the study looks into the cultural set up of the human habitats and its interrelationship with the subsurface water elemental variation. Analysis of the existing geological record of Geological Survey of India and the Shuttle Radar Topographic Mission DEM information coupled with the reconnaissance survey of the area, the research proposes 88 discrete sampling locations which can replicate the subterranean water chemistry of the concerned aquifer systems.

9 illus, 23 ref

021599   Chipade M D;Kulkarni J R;Bawiskar S M (NO, Indian Institute of Tropical Meteorology, Dr Homi Bhabha Road, Pune 411 008, Email: mukundchipade@yahoo.co.in) : Impact ofglobal warming on the energetics of lower tropospheric ultra-long waves and the Indian summer monsoon. J Earth Syst Sci 2014, 123(8), 1739-47.

Analyses of 60 years (1949-2008) of monthly energetics of the zonal waves derived from NCEP INCAR data indicate that ultra-long waves (waves 1 and 2) dominate the spectrum of lower tropospheric zonal waves during monsoon season (June-September). Westerlies over the Indian subcontinent are a source of energy to wave 1. Two oceanic anticyclones, one over Pacific and the other over Atlantic are sources of energy to wave 2. These two waves are inversely correlated. Climatology of the energetics of ultra-long waves for the two epochs 1949-1978 (CLP1) and 1979-2008 (CLP2) of 30 years indicates that the intensity ofwave 1 has decreased by about 33% whereas the intensity of wave 2 has increased by about 27%. Northward transport of sensible heat during CLP1 changes to southward during CLP2. Larger generation of zonal mean Available Potential Energy (APE) during CLP2 indicates more heating. A larger conversion of kinetic energy (KE) of wave 1 into APE of wave 1 leads to weakening of wave 1 during CLP2. In case of wave 2, lower rate of conversion of KE to APE leads to stronger wave 2 during CLP2.

11 illus, 1 table, 19 ref

021598   Chandrasekhar E;Deshmukh R;Trupti G;Biswal T K (Earth Sciences Dep, Indian Institute of Technology Bombay, Powai, Mumbai-400 076, Email: esekhar@iitb.ac.in) : Assessment of groundwater salinity in Nellore district using multi-electrode resistivity imaging technique. J Earth Syst Sci 2014, 123(8), 1809-17.

Multi-electrode resistivity imaging survey with 48 electrodes was carried out to assess the extent of inland, in the shallow subsurface in Nellore district, Andhra Pradesh, in the Eastern Ghats Belt (EG1IB) region. Resistivity data were recorded using Wenner-Schlumberger configuration at nine sites along a profile of about 55 km in length, laid perpendicular to the coast. An average spacing maintained between each site. Assessment of groundwater salinity in the study area was made interpretation of the two-dimensional (2D) geoelectrical models of all the sites together with the with the geochemical analysis results of water samples and geology. At sites closer to the coast, 2D geoelectrical of the subsurface indicate low resistivities (2-50 m) in the depth range from surface up to 15 low resistivities are due to the high salinity of the groundwater. Geochemical analysis results of samples at six locations close to the electrical resistivity survey sites also suggest high salinity and high concentrations of total dissolved solids and other chemicals at sites closer to the coast. Away from t, the resistivities in the depth range from surface up to 15 m vary in the range of 50-150 m. Accordingly, the chemical analysis of water samples collected at these sites also showed relatively low of salinity and salt concentrations in them. However, away from the coast, the resistivities vary range of 150-1500 m in the depth range from 20-40 m. While the aquaculture and agriculture activities may contribute to high salinity at the sites closer to the coast, the presence of deep-seated paleochannels aiding in transporting seawater inland, and water-rock interactions are suspected to be the chief causes for notable salinity at places away from the coast at shallow depths. We opine that the high salinity at shallow depths, coupled with the deep-seated paleochannels transporting seawater, could pose problems to probe further depths particularly using electromagnetic induction methods in the region.

3 illus, 2 tables, 19 ref

021597   Bhatta K;Ghosh B (Geology Dep, University of Calcutta, 35 Ballygunge Circular Road, Kolkata-700 019, Email: bghosh_geol@hotmail.com) : Chromian spinel-rich black sands from eastern shoreline of Andaman Island, India: Implication for source characteristics. J Earth Syst Sci 2014, 123(6), 1387-97.

Black sands rich in chromian spinel commonly occur in pockets along the eastern shoreline of Andaman Island where various types of peridotites and volcanics belonging to the Andaman ophiolite suite are exposed in close vicinity. The chemistry of these detrital chromian spinels has been extensively used here in identifying the source rocks vis-…-vis deciphering the source characteristics. The composition of the chromian spinels (Cr<35>: 0.20-0.88, Mg<35>: 0.26-0.77, Al₂ O₃: 5.04-48.21 wt.%, TiO₂: up to 1.39 wt.% and Fe^{2+/Fe3+: 1.73-9.12) varies widely signifying multiple sources, of which mantle peridotites and volcanic rocks are relevant in an ophiolitic terrain. The volcanic chromian spinels are relatively fresh, commonly euhedral, sometimes with compositional variations, and contain inclusions in contrast to the mantle peridotitic chromian spinels which are rounded, extensively fractured, and altered. We used a number of geochemical bivariate plots in order to know the provenance protoliths. The volcanic chromian spinels show geochemical characters of MORB, related to spreading centers (either MOR or back-arc) and also boninites/arc-tholeiites, related to active subduction. On the other hand, the peridotitic spinels indicate partially depleted lherzolite and depleted harzburgite source of the ophiolite suite.}

6 illus, 1 table, 51 ref

021596   Bhatpuria D;Solanki H U;Varghese S;Chauhan P (Space Application Centre, ISRO, , Ahmedabad-380 015, Email: himmatsinh@sac.isro.gov.in) : Applications of satellite derived meso-scale features and in-situ bycatch to understand sea turtlehabitats along the Indian Coast. Curr Sci 2015, 108(3), 326-9.

6 illus, 16 ref

021595   Barani H R;Lashkaripour G;Ghafoori M (Geology Dep, Ferdowsi University of Mashhad (FUM), Mashhad, Iran, Email: ha_barani@yahoo.com) : Predictive permeability model of faults in crystalline rocks; verification by joint hydraulic factor (JH) obtained from water pressure test. J Earth Syst Sci 2014, 123(6), 1325-34.

In the present study, a new model is proposed to predict the permeability per fracture in the fault zones by a new parameter named joint hydraulic factor (JH). JH is obtained from Water Pressure Test (WPT) and modified by the degree of fracturing. The results of JH correspond with quantitative fault zone descriptions, qualitative fracture, and fault rock properties. In this respect, a case study was done based on the data collected from Seyahoo dam site located in the east of Iran to provide the permeability prediction model of fault zone structures. Datasets including scan-lines, drill cores, and water pressure tests in the terrain of Andesite and Basalt rocks were used to analyse the variability of in-site relative permeability of a range from fault zones to host rocks. The rock mass joint permeability quality, therefore, is defined by the JH. JH data analysis showed that the background sub-zone had commonly <60>3 Lu (less of 5 x10^{-5 m3/s) per fracture, whereas the fault core had permeability characteristics nearly as low as the outer damage zone, represented by 8 Lu (1.3 x10-4 m3/s) per fracture, with occasional peaks towards 12 Lu (2 x10-4 m3/s) per fracture. The maximum JH value belongs to the inner damage zone, marginal to the fault core, with 14-22 Lu (2.3 x 10-4-3.6 x10-4 m3/s) per fracture, locally exceeding 25 Lu (4.1 x 10-4 m3/s) per fracture. This gives a proportional relationship for JH approximately 1:4:2 between the fault core, inner damage zone, and outer damage zone of extensional fault zones in crystalline rocks. The results of the verification exercise revealed that the new approach would be efficient and that the JH parameter is a reliable scale for the fracture permeability change. It can be concluded that using short duration hydraulic tests (WPTs) and fracture frequency (FF) to calculate the JH parameter provides a possibility to describe a complex situation and compare, discuss, and weigh the hydraulic quality to make predictions as to the permeability models and permeation amounts of different zone structures.}

8 illus, 1 table, 48 ref

020575   Zamani A M R;Monadi M;Zarei H (Hydrology and Water Resources Engineering Dep, Faculty of Water Science, Shahid Chamran Univ of Ahvaz, Khuzestan, Iran, Email: reza.zamani65@yahoo.com) : Using a first order markov chain model and SPI index to forecasting, monitoring and zoning of meteorological drought case study: Chahar Mahal and Bakhtiari province, Iran. J Envir Res Dev 2013, 8(2), 316-24.

The objective of this research was to examine and forecast the intensity, duration, frequency and extent of droughts in Chahar Mahal and Bakhtiari province of Iran for the 120 next months using the first order Markov chain model and the time series of Standardized Precipitation Index (SPI) in the three-month time scale. For this, precipitation data within the same statistical period of 30 years (1983-2012) in 1 time scales of 3 months from 12 stations located within the province were used. The results were shown that in 3months time scale, about 70 percent of the condition was normal and about 15-20 percent of the drought conditions have been occurred. Also likely of remains in the drought trap for all stations is more than 40 percent and it will be more in the South and South- East regions of the province. According to the results, the probability of transition from dry to wet conditions in the central part of the province is more than elsewhere. And droughts in the south and south-east of the province were of higher intensity and longer duration than elsewhere. According to calculated balance probability matrix the value of balance probability of drought is more than wet years in the province.

1 illus, 6 tables, 20 ref

020574   Vishal V;Sudhir Kumar;Singhal D C (Hydrology Dep, Indian Institute of Technology, Roorkee, Roorkee-247 667, Email: vikrant.vishal003@gmail.com) : Estimation of groundwater recharge in National Capital Territory, Delhi using groundwater modeling. J Indian Wat Resour Soc 2014, 34(1), 15-21.

National Capital Territory, Delhi in India is under the grip of extreme pressure to meet demand for its water resources due to urbanization, improvements in living standards, expanding population etc. Therefore, quantitative evaluation of spatial and temporal distribution of groundwater recharge is a pre-requisite for operating ground water resources system in an optimal manner and meet the demand. The main objective of this study was to predict groundwater recharge in NCT of Delhi. The methodology was achieved using numerical groundwater model (VISUAL MODFLOW, 4.3). MODFLOW model is derived from a combination of topology, soil type, land use, well location using geographic information systems (GIS). The model was calibrated and validated and then used to predict groundwater recharge. The output of the model was found to be in agreement with the earlier records. Moreover, the simulation results also show reasonable declination of water table elevations in the study area during the period of study.

10 illus, 1 table, 14 ref

020573   Vazeed Pasha S;Satish K V;Sudhakar Reddy C; Prasada Rao P V V;Jha C S (Forestry & Ecology Group, National Remote Sensing Centre, ISRO, Balanagar, Hyderabad-500 037, Email: drsudhakarreddy@gmail.com) : Satellite image based quantification of invasion and patch dynamics of mesquite (Prosopis juliflora) in Great Rann of Kachchh, Kachchh biospere reserve, Gujarat, India. J Earth Syst Sci 2014, 123(7), 1481-90.

The invasion of alien species is a significant threat to global biodiversity and the top driver of climate change. The present study was conducted in the Great Rann of Kachchh, part of Kachchh Biosphere Reserve, Gujarat, India, which has been severely affected by invasion of Prosopis juliflora. The invasive weed infestation has been identified using multi-temporal remote sensing datasets of 1977, 1990. 1999, 2005 and 2011. Spatial analyses of the transition matrix, extent of invasive colonies, patchiness, coalescence and rate of spread were carried out. During the study period of three and half decades, almost 295 km of the natural land cover was converted into Prosopis cover. This study has shown an increment of 42.9% of area under Prosopis cover in the Great Rann of Kachchh, part of the Kachchh Biosphere Reserve during 1977 to 2011. Spatial analysis indicates high occupancy of Prosopis cover with most of the invasion (95.9%) occurring in the grasslands and only 4.1% in other land cover types. The process of Prosopis invasion shows high patch initiation, followed by coalescence, indicating aggressive colonization of species. The number of patches within an area of <60> 1 km^{2 increased from 1977 to 2011, indicating the formation of new Prosopis habitats by replacing the grasslands. The largest patch of Prosopis cover increased from 144 km2 in 1977 to 430 km2 in 2011, The estimated mean patch size was 7.8 km2 in 1977. The mean patch size was largest during 2011, i.e.; 9 km2. The annual spread rate for Prosopis has been estimated as 2.1% during 2005 2011. The present work has investigated the long term changes in Prosopis cover in the Great Rann of Kachchh, part of Kachchh Biosphere Reserve. The spatial database generated will be useful in preparing strategies for the management of Prosopis juliflora.}

8 illus, 4 tables, 35 ref

020572   Sharma M K;Jain C K;Singh O (NO, National Institute of Hydrology, Roorkee-247 667, Email: mks@nih.ernet.in) : Characterization of point sources and water quality assessment of river Hindon using water quality index. J Indian Wat Resour Soc 2014, 34(1), 53-64.

River Hindon, an important tributary of river Yamuna flowing through the districts of Western Uttar Pradesh, is subjected to varying degree of pollution caused by numerous untreated and/or partially treated waste inputs of municipal and industrial effluents. In the present investigation, assessment of the water quality characteristics of different point sources contributing river Hindon has been carried out by collecting water and wastewater samples during pre- and post-monsoon seasons during the year 2012. Maximum value of BOD (261 mg/L) was observed in Star Paper Mill Drain. The higher values of BOD and COD observed in the drains indicate high degree of organic pollution rendering the water unsuitable even for bathing purpose. At almost all sites of the upstream and mid-section of the river Hindon, DO was observed to be 0 mg/L because of high organic load in the river water. BOD and COD concentration in river Hindon varies from 3.3 to 65 mg/L and 28 to 338 mg/L in pre-monsoon season while 0 to 139 mg/L and 24 to 388 mg/L in post-monsoon season respectively. Further water quality of river Hindon has been assessed using water quality index and the quality of river Hindon was observed to be bad at all site which may be attributed to untreated and/or partially treated waste inputs of municipal and industrial effluents joining the river.

3 illus, 6 tables, 48 ref

020571   Sharma A;Saikia A;Khare P;Baruah B P (Coal Chemistry Div, CSIR-North East Institute of Science & Technology, Jorhat-785 06, Email: bpbaruah@yahoo.com) : Genesis of some tertiary Indian coals from the chemical composition of ash - a statistical approach: part 1. J Earth Syst Sci 2014, 123(7), 1705-15.

In the present investigation, 37 numbers of high sulphur tertiary coal samples from Meghalaya, India have been studied on the basis of proximate and ash analysis. Various statistical tools like Bivariant Analysis, Principal Component Analysis (PCA) and Hierarchical Clustering Analysis (HCA), and also the geochemical indicators were applied to determine the dominant detrital or authigenic affinity of the ash forming elements in these coals. The genetic interpretation of coal as well as the coal ash has been carried out based on chemical compositions of high temperature ash (HTA) by using Detrital/Authigenic Index. X-Ray Diffraction (XRD) analysis was also carried out to study the mineralogy of the studied coal ashes. Both statistical tools and geochemical indicators have confirmed the detrital nature of these coals as well as the ash forming elements.

4 illus, 5 tables, 35 ref

020570   Sahoo P R;Venkatesh A S (Applied Geology Dep, Indian School of Mines, Dhanbad-826 004, Email: asvenkatesh@hotmail.com ) : 'Indicator' carbonaceous phyllite/ graphitic schist in the archean kundarkocha gold deposit, singhbhum orogenic belt, Eastern India: implications for gold mineralization vis-a-vis organic matter. J Earth Syst Sci 2014, 123(7), 1693-1703.

Carbonaceous rocks in the form of graphitic schist and carbonaceous phyllite are the major host rocks of the gold mineralization in Kundarkocha gold deposit of the Precambrian Singhbhum orogenic belt in eastern India. The detection of organic carbon, essentially in the carbonaceous phyllite and graphi-tized schist within the Precambrian terrain, is noted from this deposit. A very close relationship exists between gold mineralization and ubiquitous carbonaceous rocks containing organic carbon that seems to play a vital role in the deposition of gold in a Precambrian terrain in India and important metalloge-netic implications for such type of deposits elsewhere. However, the role played by organic matter in a Precambrian gold deposit is debatable and the mechanism of precipitation of gold and other metals by organic carbon has been reported elsewhere. Fourier transform infrared spectroscopy (FTIR) results and total organic carbon (TOC) values suggest that at least part of the organic material acted as a possible source for the reduction that played a significant role in the precipitation of gold. Lithological, electron probe analysis (EPMA), fluid inclusions associated with gold mineralization, Total Carbon (TC). TOC and FTIR results suggest that the gold mineralization is spatially and genetically associated with graphitic schist, carbonaceous phyllite/shale that are constituted of immature organic carbon or kero-gen. Nano-scale gold inclusions along with free milling gold are associated with sulfide mineral phases present within the carbonaceous host rocks as well as in mineralized quartz-carbonate veins. Deposition of gold could have been facilitated due to the organic redox reactions and the graphitic schist and carbonaceous phyllite zone may be considered as the indicator zone.

6 illus, 1 table, 54 ref

020569   Ramesh Chander;Tomar S K (NO, , <35>290 Sector -4, Mansa Devi Complex, Panchkula-134 114, Email: sktomar66@gmail.com) : Integral-free expression for short-term changes in fault stability due to pore pressure induced when a point load is placed on the pervious boundary of a porous elastic half space containing a fault. J Earth Syst Sci 2014, 123(7), 1729-38.

A concentrated load with step-function time behaviour is placed normal to the planar, pervious boundary of a porous elastic half space (PEHS) with compressible constituents. A planar fault exists in the PEHS in such a way that the poroelastic behaviour of the medium is unhindered. We derive an approximate but integral-free expression for CFSCPP, i.e., changes in fault stability due to changes in pore pressure, at a point not too far off the line along which the load acts. But, in the interest of simplicity, the main discussion is focussed on a consideration of CFSCPP at a point P located on the fault at depth z directly beneath the load. It is convenient to introduce dimensionless time t_D directly proportional to real time t. The constant of proportionality is 4c/z^{2, where c is hydraulic diffusivity. The derived approximate expression gives results with an accuracy of greater than 99% for limited values of t_D after the load is imposed. We learn from the derived expression that, for a given z, fault stability undergoes an initial sudden decrease commensurate with the undrained pore pressure induced in the PEHS. This is followed by a more gradual decrease in fault stability with increasing t_D until a minimum is reached. The real time t to minimum fault stability increases with z. The magnitude of CFSCPP decreases with z as z-2 for a given t_D in the permissible range. The derived expression and the inferences based on it should be useful during earth science investigations of the possible hazards due to reactivation of a pre-existing shallow fault when a civil engineering project involving imposition of a heavy load on the earth's surface is to be executed nearby. They should be useful also for investigations if a shallow earthquake occurs near such a project soon after its execution.}

2 illus, 16 ref

020568   Prasad R;Acharya T;Chakrabarti S (Geology Dep, Hooghly Mohsin College, Burdwan Univ, Chinsurah-712 101, Email: tacharya3@yahoo.com) : Locating zones of high discharging wells for protection and management of groundwater resources in precambrian metamorphic rocks of Purulia district, West Bengal, India - a case study by hydrostructural domain approach. J envir Sociobiol 2014, 11(1), 11-24.

Locating sites of high discharging wells in metamorphic crystalline terrain is still a difficult problem imposing inadequate protection and management for groundwater resources. The present study attempts to determine this technique in a Precambrian metamorphic rock in and around Balarampur, Purulia district, West Bengal, India using lineaments, joints/fractures and well data with the help of software approach. The joints/fracture study consists of using hydraulically significant fracture data to generate representative modal and coefficient of variance (Cv) for each domain. Lineament study incorporates estimation of the hydraulically significant FCL and their percentage of occurrence in each domain. The hydrostructural domain based study identifies areas within the shear zone (D2) and south of the shear zone (D3) as hydraulically significant region than the region to north of the shear zone (D1). The modal and Cv values of well discharges also signify D2 and D3 as hydraulically significant part of the study area. Existing wells show discrete increase in discharge from Dl. to D3 through D2, with high discharging wells (= 4000 litre per day) occurring in groups in linear fashion, defining 'well lines', in close proximity to the determined FCL. Thus the study validated the hydrostructural domain based analysis for locating high discharging wells, indicating the sites for protection and management of groundwater resources for sustainable utilization and development in Precambrian metamorphic terrain.

5 illus, 1 table, 47 ref

020567   Pophare A M;Balpande U S (Geology Dep, RTM Nagpur Univ, Nagpur-440 001, Email: apophare@gmail.com) : Morphometric analysis of Suketi river basin, Himachal Himalaya, India. J Earth Syst Sci 2014, 123(7), 1501-15.

Suketi river basin is located in the Mandi district of Himachal Pradesh, India. It encompasses a central inter-montane valley and surrounding mountainous terrain in the Lower Himachal Himalaya. Morpho-metric analysis of the Suketi river basin was carried out to study its drainage characteristics and overall groundwater resource potential. The entire Suketi river basin has been divided into five sub-basins based on the catchment areas of Suketi trunk stream and its major tributaries. Quantitative assessment of each sub-basin was carried out for its linear, areal, and relief aspects. The analysis reveals that the drainage network of the entire Suketi river basin constitutes a 7th order basin. Out of five sub-basins. Kansa khad sub-basin (KKSB), Gangli khad sub-basin (GKSB) and Ratti khad sub-basin (RKSB) are 5th order sub-basins. The Dadour khad sub-basin (DKSB) is 6th order sub-basin, while Suketi trunk stream sub-basin (STSSB) is a 7th order sub-basin. The entire drainage basin area reflects late youth to early mature stage of development of the fluvial geomorphic cycle, which is dominated by rain and snow fed lower order streams. It has low stream frequency (Fs) and moderate drainage density (Dd) of 2.69 km/km^{2. Bifurcation ratios (Rb) of various stream orders indicate that streams up to 3rd order arc surging through highly dissected mountainous terrain, which facilitates high overland flow and less recharge into the subsurface resulting in low groundwater potential in the zones of 1st. 2nd, and 3rd order streams of the Suketi river basin. The circulatory ratio (Rc) of 0.65 and elongation ratio (Re) of 0.80 show elongated nature of the Suketi river basin, while infiltration number (If) of 10.66 indicates dominance of relief features and low groundwater potential in the high altitude mountainous terrain. The asymmetry factor (Af) of Suketi river basin indicates that the palaeo-tectonic tilting, at drainage basin scale, was towards the downstream right side of the drainage basin. The slope map of Suketi river basin has been classified into three main zones, which delineate the runoff zone in the mountains, recharge zone in the transition zone between mountains and valley plane, and discharge zone in the plane areas of Balh valley.}

7 illus, 2 tables, 70 ref

020566   Morad N A;Masoud M H;Abdel Moghith S M (Hydrology Dep, Desert Research Centre, Cairo, Egypt, Email: zakimilad@hotmail.com) : Hydrologic factors controlling groundwater salinity in northwestern coastal zone, Egypt. J Earth Syst Sci 2014, 123(7), 1567-78.

The aim of this article is to assess the main factors influencing salinity of groundwater in the coastal area between El Dabaa and Sidi Barani, Egypt. The types and ages of the main aquifers in this area are the fractured limestone of Middle Miocene, the calcareous sandstone of Pliocene and the Oolitic Limestone of Pleistocene age. The aquifers in the area are recharged by seasonal rainfall of the order of 150 mm/year. The relationship of groundwater salinity against the absolute water level, the well drilling depth, and the ability of aquifer to recharge has been discussed in the present work. The ability of aquifer to locally recharge by direct rainfall is a measure of the vertical permeability due to lithological and structural factors that control groundwater salinity in the investigated aquifers. On the other hand, the fracturing system as well as the attitude of the surface water divide has a prime role in changing both the mode of occurrence and the salinity of groundwater in the area. Directly to the west of Matrouh, where the coastal plain is the narrowest, and east of Barrani, where the coastal plain is the widest, are good examples of this concept, where the water salinity attains its maximum and minimum limits respectively. Accordingly, well drilling in the Miocene aquifer, in the area between El Negila and Barrani to get groundwater of salinities less than 5000 mg/1 is recommended in this area, at flow rate less than 10 m^{3/hr/well. In other words, one can expect that the brackish water is probably found where the surface water divide is far from the shore line, where the Wadi fill deposits dominate (Quaternary aquifer), acting as a possible water salinity by direct rainfall and runoff.}

12 illus, 3 tables, 6 ref

020565   Mitra S;Mishra A (Agricultural & Food Engineering Dep, Indian Institute of Technology, Kharagpur, Kharagpur-721 302, Email: subhuitt@gmail.com) : Hydrologic response to climatic change in the baitarni river basin. J Indian Wat Resour Soc 2014, 34(1), 24-33.

Streamflow and sediment yield response to climate change in the Baitarni river basins (BRB), Eastern India: has been investigated employing SWAT (Soil and Water Asessment Tool) model. Model was calibrated and validated by comparing measured streamflow and associated sediment concentration at Anandpur gauging station, located inside the river basin. Climate change impact analyses were performed by- i) assuming scenarios of increased temperature (+2 °C, +4 °C and +6 °C), varied rainfall (±20% at ±5% increment) and increased atmospheric carbon dioxide (CO₂) concentrations (330 ppm, 495 ppm and 660 ppm); and ii) by extending historical rainfall (1974 to 2004) trend in future from 2005 to 2099. The trend analysis has shown that average annual rainfall at the Baitarni river basin has increased by 8.8 mm per year in the last 30 years which has resulted to an increase in streamflow in the river basin. Climate change sensitivity showed an increasing streamflow to independent increase in rainfall whereas showed decreasing streamflow to decreased rainfall and increased temperature in the basin. The increased atmospheric CO₂ concentrations, independently, showed an increase in streamflow. The analysis shows that the water availability at the Baitarni river basin is expected to increase in future under linear increase in rainfall since historic and expected increasing rainfall trend persisting in future. The predicted future scenarios developed by SWAT model gave the normalized daily rainfall distribution and was unable to catch the expected extreme rainfall conditions. This characteristic of predicted rainfall showed that the method used to study and estimate future water resources does not hold good for the estimation of sediment yield.

9 illus, 1 table, 21 ref

020564   Kotal S D;Bhattacharya S K;Roy Bhowmik S K; Kundu P K (NO, , India Meteorological Dep, NWP Div, New Delhi-110 003, Email: sumit.kumar.bhattacharya@gmail.com) : Forecasting of cyclone viyaru and phailin by NWP-based cyclone prediction system (CPS) of IMD - an evaluation. J Earth Syst Sci 2014, 123(7), 1637-52.

An objective NWP-based cyclone prediction system (CPS) was implemented for the operational cyclone forecasting work over the Indian seas. The method comprises of five forecast components, namely (a) Cyclone Genesis Potential Parameter (GPP), (b) Multi-Model Ensemble (MME) technique for cyclone track prediction, (c) cyclone intensity prediction, (d) rapid intensification, and (e) predicting decaying intensity after the landfall. GPP is derived based on dynamical and thermodynamical parameters from the model output of IMD operational Global Forecast System. The MME technique for the cyclone track prediction is based on multiple linear regression technique. The predictor selected for the MME are forecast latitude and longitude positions of cyclone at 12-hr intervals; up to 120 hours forecasts from five NWP models namely, IMD-GFS, IMD-WRF, NCEP-GFS, UKMO, and JMA. A statistical cyclone intensity prediction (SCIP) model for predicting 12 hourly cyclone intensity (up to 72 hours) is developed applying multiple linear regression technique. Various dynamical and thermodynamical parameters as predictors are derived from the model outputs of IMD operational Global Forecast System and these parameters are also used for the prediction of rapid intensification. For forecast of inland wind after the landfall of a cyclone, an empirical technique is developed. This paper briefly describes the forecast system CPS and evaluates the performance skill for two recent cyclones Viyaru (non-intensifying) and Phailin (rapid intensifying), converse in nature in terms of track and intensity formed over Bay of Bengal in 2013. The evaluation of performance shows that the GPP analysis at early stages of development of a low pressure system indicated the potential of the system for further intensification. The 12-hourly track forecast by MME, intensity forecast by SCIP model, and rapid intensification forecasts are found to be consistent and very useful to the operational forecasters. The error statistics of the decay model shows that the model was able to predict the decaying intensity after landfall with reasonable accuracy. The performance statistics demonstrates the potential of the system for improving operational cyclone forecast service over the Indian seas.

20 illus, 4 tables, 24 ref

020563   Kotal S D;Bhattacharya S K;Roy Bhowmik S K; Kundu P K (NO, , India Meteorological Dep, NWP Div, New Delhi-110 003, Email: sumit.kumar.bhattacharya@gmail.com) : Growth of cyclone Viyaru and Phailin - a comparative study. J Earth Syst Sci 2014, 123(7), 1619-35.

The tropical cyclone Viyaru maintained a unique quasi-uniform intensity during its life span. Despite being in contact with sea surface for <62>120 hr travelling about 2150 km, the cyclonic storm (CS) intensity, once attained, did not intensify further, hitherto not exhibited by any other system over the Bay of Bengal. On the contrary, the cyclone Phailin over the Bay of Bengal intensified into very severe cyclonic storm (VSCS) within about 48 hr from its formation as depression. The system also experienced rapid intensification phase (intensity increased by 30 kts or more during subsequent 24 hours) during its life time and maximum intensity reached up to 115 kts. In this paper, a comparative study is carried out to explore the evolution of the various thermodynamical parameters and possible reasons for such converse features of the two cyclones. Analysis of therrnodynamical parameters shows that the development of the lower tropospheric and upper tropospheric potential vorticity (PV) was low and quasi-static during the lifecycle of the cyclone Viyaru. For the cyclone Phailin, there was continuous development of the lower tropospheric and upper tropospheric PV, which attained a very high value during its lifecycle. Also there was poor and fluctuating diabatic heating in the middle and upper troposphere and cooling in the lower troposphere for Viyaru. On the contrary, the diabatic heating was positive from lower to upper troposphere with continuous development and increase up to 6°C in the upper troposphere. The analyses of cross sections of diabatic heating, PV, and the 1000-500 hPa geopotential metre (gpm) thickness contours indicate that the cyclone Viyaru was vertically tilted (westward) and lacked axisyrnmetry in its structure and converse features (axisymmetric and vertical) that occurred for the cyclone Phailin. In addition, there was a penetration of dry air in the middle troposphere of Viyaru, whereas high moisture existed in the middle troposphere of Phailin. The vertical wind shear (5-10 ms^{-1) near the core of the storm region between 850 and 200 hPa was favourable for both the systems but was higher in the northern region of the cyclone Viyaru. The divergent development of these therrriodynamic features conspired to produce converse characteristic of the two cyclones.}

21 illus, 31 ref

020562   Jana P K;Bhattacharyya S;Banerjee A (Chemistry Dep, Institute of Education (P. G) for Women, Chandernagore, Hooghly 712 138, Email: pkjjngl@yahoo.co.in) : Effect of some climatic parameters on tropospheric and total ozone column over Alipore (22.52°N, 88.33°E), India. J Earth Syst Sci 2014, 123(7), 1653-69.

The paper presents the nature of variations of tropospheric and total ozone column retrieved from the Convective Cloud Differential (CCD) technique, Ozone Monitoring Instrument (OMI), and Total Ozone Mapping Spectrometer (TOMS) data, National Aeronautics and Space, Administrations (NASA), USA, respectively; surface temperature, relative humidity, total rainfall, ozone precursors (non-methane hydrocarbon, carbon monoxide, nitrogen dioxide, and sulphur dioxide) that are collected from India Meteorological Department (IMD), Alipore, Kolkata; solar insolation obtained from Solar Geophysical Data Book and El-Nino index collected from National Climatic Data Center, US Department of Commerce. National Oceanic and Atmospheric Administration, USA. The effect of these climatic parameters and ozone precursors on ozone variations is critically analyzed and explained on the basis of linear regression and correlation. It has been observed that the maximum, minimum and mean temperature, relative humidity, solar insolation, tropospheric, and total ozone column (TOC) showed slight increasing tendencies from October 2004 to December 2011, while total rainfall and El-Nino index showed little decreasing tendencies for the same period. Amongst selected climatic parameters and ozone precursors, the solar insolation and the average temperature had a significant influence on both, the tropospheric ozone and total ozone column formation. The solar insolation had contributed more in tropospheric ozone than in total ozone column; while El-Nino index had played a more significant role in total ozone column build up than in tropospheric ozone. Negative correlation was observed between almost all ozone precursors with the tropospheric and total ozone. The tropospheric ozone and total ozone column were also significantly correlated. The level of significance and contribution of different climatic parameters are determined from correlation technique and Multiple Linear Regression (MLR) method. The related chemical kinetics for ozone production processes has been critically described.

19 illus, 2 tables, 66 ref

020561   Ghosh A (NO, Geological Survey of India, SU: Odisha, Bhubaneswar, Email: aryaaghosh@gmail.com) : Some aspects on mineral resources of Odisha. J envir Sociobiol 2014, 11(1), 1-10.

Mineral resources play a major role in industrial development of the country. These mineral resources are mostly hosted by Precambrian rocks which incidentally occupy major part of the State Odisha. In the present study, thrust has been put on some of the very important mineral deposits of Odisha, such as, chromite, platinum group of elements (PGE), bauxite, manganese ore, nickel ore, iron ore and graphite. Amongst these mineral commodities except graphite, Odisha possesses the highest resource in India. In case of graphite resource, the State comes after Tamil Nadu. Nature of host rock for these minerals, their utilization and total resources/reserves have been documented. The pattern of consumption of those minerals in the country over the last four years has been studied as well. An attempt has been made to statistically predict the time period by which the proven resources for these minerals in Odisha will be fully exhausted by projecting the increasing trend of consumption of the said minerals. In view of the possible future status of these mineral resources, alternative thought process has to be initiated for sustainable industrial expansion. Apart from search for new mineral deposits or their possible substitutes, conservation of these non-renewable natural resources needs to be prioritized.

6 illus, 4 tables, 3 ref

020560   Dhiman S D (Civil Engineering Dep, Birla Vishvakarma Mahavidyalaya, Vallabh Vidyanagar, Gujarat, Email: dhimansanjay18@hotmail.com) : Groundwater quality assessment for irrigation use in Rajkot district, Gujarat. J Indian Wat Resour Soc 2014, 34(1), 34-9.

Groundwater quality of Rajkot district in Gujarat State was assessed for irrigation water use. Twenty seven groundwater samples were considered for calculating the sodium adsorption ratio (SAR), residual sodium carbonate (RSC), magnesium hazard ratio (MH), sodium percent (%Na), permeability index (PI), and Index Base Exchange (IBE) values. USSL based graphical classification of groundwater samples is also carried out. Results reveal that majority of sites have SAR <60> 10 indicating water class to be of excellent quality and 81.48% samples have RSC less than the permissible 1.5. It is observed that 51.85% samples have MH ratio values greater than 50. The presence of more magnesium in water than calcium increases the degree of magnesium saturation and deteriorates the soil structure and decrease soil productivity. It is found that 59.25% samples showed negative chloro alkaline indices ratios with an indirect Base Exchange reaction. In contrast 40.75% samples showed positive chloro alkaline indices indicating a direct Base Exchange reaction. Furthermore 70.37% sites have (Ca^{2++Mg2+) <62>HCO₃- indicating as base exchanged-hardened waters while remaining 29.63% samples have HCO₃- <62> (Ca2++Mg2+) which may be referred as base exchanged-softened waters. It is recommended that for salinity control adequate arrangement of drainage and selection of crops with good tolerance is to be adopted.}

2 illus, 5 tables, 18 ref

020559   Dariane A B;Azimi S;Zakerinejad A (Civil Engineering Dep, K.N. Toosi Univ of Technology, Tehran, Iran, Email: borhani@kntu.ac.ir) : Artificial neural network coupled with wavelet transform for estimating snow water equivalent using passive microwave data. J Earth Syst Sci 2014, 123(7), 1591-1601.

Snow Water Equivalent (SWE) is an important parameter in hydrologic engineering involving the stream-flow forecasting of high-elevation watersheds. In this paper, the application of classic Artificial Neural Network model (ANN) and a hybrid model combining the wavelet and ANN (WANN) is investigated in estimating the value of SWE in a mountainous basin. In addition, k-fold cross validation method is used in order to achieve a more reliable and robust model. In this regard, microwave images acquired from Spectral Sensor Microwave Imager (SSM/I) are used to estimate the SWE of Tehran sub-basins during 1992-2008 period. Also for obtaining measured SWE within the corresponding Equal-Area Scalable Earth-Grid (EASE-Grid) cell of SSM/I image, approach of Cell-SWE extraction using height-SWE relations is applied in order to reach more precise estimations. The obtained results reveal that the wavelet-ANN model significantly increases the accuracy of estimations, mainly because of using multi-scale time series as the ANN inputs. The Nash-Sutcliffe Index (NSE) for ANN and WANN models is respectively 0.09 and 0.44 which shows a firm improvement of 0.35 in NSE parameter when WANN is applied. Similar trend is observed in other parameters including RMSE where the value is 0.3 for ANN and 0.07 for WANN.

4 illus, 3 tables, 35 ref

020558   Dabral P P;Pandey P K;Tushar Kumar; Chakraborty S (Agricultural Engineering Dep, NERSIT, Nirjuli (Itanagar-791 109, Email: ppdabral1962@gmail.com) : Determination of discharge coefficient and head-discharge relationships of different hydraulic structures. J Indian Wat Resour Soc 2014, 34(1), 40-52.

Glass sided tilting flow channel based laboratory study was carried out to determine the discharge coefficient and head-discharge relationships for hydraulic structures i.e. Broad Crested Weir, Crump Weir, Sluice gate. Radial Gate and Dam Spillway. The average value of Coefficient of Discharge for Broad Crested Weir, Crump Weir, Sluice Gate, Radial Gate and Dam Spillway was found to be 0.44, 0.85, 0.76, 0.82 and 1.03 respectively. Furthermore, the C_a with h/a was linearly related and there was power relationship between Discharge and Head with R^{2 ranging from 0.80 to 0.99 for all the structures under study.}

2 illus, 6 tables, 11 ref

020557   Arumugm Y;Gupta A K;Panigrahi M K (NO, Indian Institute of Technology, Kharagpur-721 302, Email: agl.yuva@gmail.com) : Species diversity variations in neogene deep-sea benthic foraminifera at ODP hole 730A, western arabian sea. J Earth Syst Sci 2014, 123(7), 1671-80.

Deep-sea benthic foraminifera are an important and widely used marine proxy to understand paleoceano-graphic and paleoclimatic changes on regional and global scales, owing to their sensitivity to oceanic and climatic turnovers. Some species of benthic foraminifera are sensitive to changes in water mass properties whereas others are sensitive to organic fluxes and deep-sea oxygenation. Benthic faunal diversity has been found closely linked to food web, bottom water oxygen levels, and substrate and water mass stability. The present study is aimed at analyzing species diversity trends in benthic foraminifera and their linkages with Indian monsoon variability during the Neogene. Species diversity of benthic foraminifera is examined in terms of number of species (S), information function (H), equitability (E) and Sanders' rarefied values, which were combined with relative abundances of high and low productivity benthic foraminifera at Ocean Drilling Program Hole 730A, Oman margin, western Arabian Sea. The Oman margin offers the best opportunity to understand monsoon-driven changes in benthic diversity since summer monsoon winds have greater impact on the study area. The species diversity was higher during the early Miocene Climatic Optimum (<126>17.2-16.4 Ma) followed by a decrease during 16.4-13 Ma coinciding with a major increase in Antarctic ice volume and increased formation of Antarctic Bottom Water. All the diversity parameters show an increase during 13 11.6 Ma, a gradual decrease during 11.6-9 Ma and then an increase with a maximum at 7 Ma. Thereafter the values show little change until 1.2 Ma when all the parameters abruptly decrease. The benthic foraminiferal populations and diversity at Hole 730A were mainly driven by the Indian monsoon, and polar waters might have played a minor or no role since early Neogene period as the Arabian Sea is an enclosed basin.

4 illus, 73 ref