July 2017

July, 2017   ||  Volume 21 No.4


Geotechnical Studies using Geophysical Logs of Sravanapalli –II Dipside Block, Adilabad District, Telangana, India

K. Venkatesh*1, V. Suman1, K. A. V. L. Prasad2, M. Shanmukha Rao3 and A. Srinivasa Rao4
1Senior Geophysicist, Exploration Division, SCCL, Bellampalli, 504 251
2Superintending Geophysicist, Exploration Division, SCCL, Bellampalli, 504 251
3Superintending Geophysicist, Exploration Division, SCCL, Kothagudem, 507 101
4Deputy General Manager (Geophysics) Exploration Division, SCCL, Kothagudem, 507 101
*Corresponding Author: venky.geo@gmail.com

Strata control invariably depends upon precise understanding of geological and geotechnical characteristics of overburden strata of coals which helps in managing the risks associated with various forms of strata instability. Geophysical logs of exploratory boreholes, besides overcoming the inherent limitations of conventional methods address all the geotechnical characteristics of the surrounding strata so that geotechnical engineers can design mine openings, which differ according to the mine plan. The present study provides all the geological and geotechnical characteristics of Permian coals of Barakar Formation of Sravanapalli -II dipside block of North Godavari sub-basin, Telangana, India. The 200m thick coal-bearing Barakar is resolved into Lower and Upper sequences. The coals of Lower sequence have roof rocks varying from sandstones to shale in specific directions which are prone to wash out. The High strength massive sandstones having Uniaxial Compressive Strength (UCS) of 30 MPa to 50MPa constitute the overburden strata of lower set of coals. The coals of Upper sequence contain one metre to two metre thick beds of clays/shales along their roofs and medium strength sandstones of 10MPa to 20MPa. All these interburden strata of coals contain couple of one metre to two metre thick lenses of Very High to Extremely High strength sandstones of UCS of 60MPa to 200MPa. These overburden strata are also classified in terms of Geophysical Strata Rating (GSR) computed from suite of geophysical logs. Dynamic moduli of these sediments are even computed using density and sonic logs. These logs now give wider range and several options by providing petrophysical, elastic and mechanical properties of overburden strata to earth scientists involved in mine planning.
Key words: P-wave, UCS, CMRR, GSR, SS-80.

Assessment of Hydro-geochemical Evolution Mechanism and Suitability of Groundwater for Domestic and Irrigation Use in and Around Ludhiana city, Punjab, India

Sakambari Padhi1, R. Rangarajan*2, K. Rajeshwar3, Sahebrao Sonkamble2 and V. Venkatesam4
1Post-doctoral researcher, Department of Environment systems, Graduate school of Frontier Sciences,
The University of Tokyo, Japan
2Scientist, Groundwater division, CSIR-NGRI, Hyderabad
3Scientist, Vimta Lab, Hyderabad
4Hydrogeologist, Central Groundwater Board, Central Region, Nagpur
*Corresponding Author: rangarajanngri@gmail.com

Groundwater and surface water samples in and around Punjab Agricultural University (PAU) Ludhiana were collected and analyzed for physico-chemical characteristics. The groundwater in the study area was found to be controlled by rock-water interaction, carbonate mineral (calcite and dolomite) weathering and ion exchange processes. The water facies were mainly of Ca-Mg-HCO3 and Na-HCO3 types, showing fresh water characteristics. All the groundwater samples were found to be with in the safe limits with respect to the dissolved solids, major cations, major anions and trace elements making it suitable for domestic use. However, the hardness may affect the acceptability of this groundwater for drinking. Most of the groundwater samples are suitable for irrigation, considering salinity hazard, sodicity hazard and bicarbonate hazard. However, magnesium hazard is found to persist in 63% of groundwater samples. The canal water is found to be of good quality for irrigation.
Key words: Hydro-geochemical evolution, Water quality, Domestic and Irrigation use, Salinity hazard, Sodicity hazard, Bicarbonate hazard, Magnesium hazard.

A Hybrid Prediction Algorithm using Naive Bayes Classifier for Improving Accuracy in Classifying LISS III Data

Kalyan Netti*1 and Y.Radhika2
1CSIR-National Geophysical Research Institute, Uppal Road, Hyderabad
2Associate Professor, CSE Dept., GITAM University, Visakhapatnam
*Corresponding Author: nettikalyan@gmail.com

We propose a hybrid model for improving the accuracy in classifying LISS III Data using Naïve Bayes Classifier. The assumption of Conditional Independence among the predictors is one of the main reasons for loss of accuracy in Naïve Bayes Classifier. The effect of conditional independence on the accuracy varies on the data chosen for analysis. As there are cases where the predictor-outcome has become null, ignoring such results is not advisable as the outcome may affect the accuracy. In this paper, remote sensing data for Land use/Land cover is used as an input to the algorithm for classification. The Linear Imaging Self Scanning Sensor (LISS-III) data of Resourcesat-2 satellite has been used for this study. The Naive Bayes algorithm has been applied to the data, and the results are compared with the standard classification methods such as Maximum likelihood classifier and Mahalanobis classifier. The result of the study shows Naive Bayes classification performs better compared to conventional classifiers such as Maximum likelihood classifier and Mahalanobis classifier.
Key words: Hybrid prediction algorithm, Naive Bayes Classifier, Conditional Independence, Supervised Classification, Maximum likelihood classifier, Mahalanobis classifier.

A complete chaotic analysis on daily mean surface air temperature and humidity data of Chennai

A. Antony suresh* and R. Samuel Selvaraj
Department of Physics, Presidency College, Chennai, Tamil Nadu, India
*Corresponding Author: antony.suresh4@gmail.com 

In this article are presented results from analysis of daily mean surface air temperature and humidity data applying nonlinear techniques. The data are collected for Chennai, India during January 1988–December 2013. The phase space, which illustrates the progress of the behavior of a nonlinear dynamical system, is reconstructed by Takens delay embedding theorem. The delay time and embedding dimension are estimated using average mutual information (AMI) and false nearest neighbor (FNN) algorithm respectively. Based on these embedding parameters (delay time τ and embedding dimension m) the correlation dimension for various embedding dimension and largest lyapunov exponent are estimated. Finally, the phase space reconstruction algorithm is employed to make a short-term prediction of the chaotic time series, whose governing equations of the system are unknown. The predicted values are in good agreement with the observed ones within 7 days, but they appear much less accurate beyond that limit (7 days). These results indicate that chaotic characteristics clearly exist in the air temperature and humidity data; techniques based on nonlinear dynamics can therefore be used to analyze and predict the air temperature.
Key words: Chaos, Phase space reconstruction, Hurst exponent, Lyapunov exponent and Poincare map.

Monsoon Could Trigger the Global Abrupt Climate Changes: New Evidence from the Bay of Bengal

Pothuri Divakar Naidu*1 and Pawan Govil2
1National Institute of Oceanography, Dona Paula 403 004, Goa, India
2Birbal Sahni Institute of Palaeosciences, 53 University Road, Lucknow – 226 007, India
*Corresponding Author: divakar@nio.org

In recent years evidence has been pouring in mainly from marine records, supporting the hypotheses that temperature changes in the Arctic and Greenland steer the intensity of the Asian Monsoon (Schulz et al., 1998; Kudrass et al., 2001; Gupta et al., 2003; Wang et al., 2001). However, the physical link between the high latitude climate and monsoons are still elusive. Here we use oxygen isotopes and Mg/Ca data of planktonic foraminifera species (Globigerinoides ruber) from a sediment core in the Bay of Bengal to reconstruct sea surface temperature (SST) and surface water oxygen isotopic values. We find that oxygen isotopic values (monsoon signal) and SST of the Bay of Bengal (BOB) lead the Dansgaard-Oeschger
(D-O) events. We, therefore suggest that the monsoon could kick the start of millennial scale abrupt climate changes through the shifts of the Intertropical Convergence Zone (ITCZ) and associated convection, water vapor supply to the tropical troposphere and latent heat penetration.
Key words: Monsoon, climate change, oxygen isotopes, planktonic foraminifera species, sea surface temperature, Dansgaard-Oeschger (D-O) events, Intertropical Convergence Zone (ITCZ).

Resorbed forsterite in the carbonatite from the Cretaceous Sung Valley Complex, Meghalaya, NE India – Implications for
crystal-melt interaction from textural studies 

V.V.Sesha Sai*1 and Shyamal Kumar Sengupta2
1Geological Survey of India, Southern Region, Hyderabad - 500068
2Director (Retd.) CPL, Geological Survey of India, Central Headquarters Kolkata – 700016
*Corresponding Author: seshu1967@gmail.com

Through this paper, we present the significance of textural studies and discuss on the petrogenetic implications of resorbed forsterite from the Sung valley carbonatite, Meghalaya, NE India. Petrographic studies revealed the presence of resorbed olivine, exhibiting conspicuous reaction rim with the surrounding carbonate in the Sung carbonatite. Studies reveal the presence of calcite as dominant mineral phase, with subordinate apatite and accessory magnetite, ilmenite and perovskite. Olivine is noticed as a conspicuous silicate phase in the carbonatite. EPMA studies indicated high Mg nature of the olivine i.e. Fo97.3. The SiO­2 content in the forsterite olivine range from 40.95 to 41.60% and MgO content from 54.43 to 56.31%. In the Fe2 / (Fe2+Mg) / (Mg/(Fe2+Mg) mineral chemistry plot, the resorbed olivine from the Sung valley carbonatite falls close to the vicinity of the forsterite end member. We present the succinct details on petrographic and mineral chemistry and discuss on the petrogenetic significance of the forsterite olivine in the Sung carbonatite. Presence of Mg rich foresterite exhibiting spectacular resorbed texture in the carbonatite of Sung Valley Complex indicate early crystallization of olivine and subsequent crystal-melt interaction between the early formed silicate and carbonate melt.
Key words: Forsterite, carbonatite, Sung valley, Meghalaya.

Intraseasonal Variability of Rainfall, Wind and Temperature during summer monsoon at an Indian tropical west coast station, Goa– Role of synoptic systems

B. S. Murthy* and R. Latha
Indian Institute of Tropical Meteorology, Dr Homi Bhabha Road, NCL Post, Pune-411008, India
*Corresponding Author: murthy@tropmet.res.in

Rain gauge data of daily rainfall and in-situ high frequency (10 Hz) measurements of turbulent wind and air temperature at Goa (15.50N, 73.80E), located on the west coast of India, are subjected to wavelet analysis to understand dominant periods of oscillations during the summer monsoon. Heavy (subdued) rainfall spells over the west coast of India at Goa are associated with intense phase of 3-7 day (10-20 day) mode of Monsoon Rainfall Oscillation (MRO) as revealed by wavelet analysis of daily rainfall. This is unlike that over the monsoon core region where active or weak monsoon is associated with the strong phase of 10-20 day or 30-60 day mode of oscillations, respectively. Intense or weak rainfall spells are found to be coincident with positive or negative wind anomalies at 850 hPa over the Arabian Sea off Goa coast. Maxima or minima in the relative contribution of 3-7 day mode to total variance are mostly coincident with active or feeble/no ‘offshore trough’ or Somali Jet positive or negative wind anomalies indicating that ‘offshore trough’ and ‘Somali Jet’ oscillations could apparently be responsible for dominance of 3-7 day mode over other modes. Oscillations of wind and temperature reveal that 3-7 day and 10-20 day modes are in opposite phase, especially during July and August. When the convection associated with the lows/depressions in the Bay of Bengal extends up to the west coast, the 3-7 day mode of rainfall and wind are ‘in phase’ and they are in ‘opposite phase’ when the ‘offshore trough’ is prominent.
Key words: Monsoon rainfall oscillation, West coast of India, 3-7 day mode, offshore trough.

Forecasting El Nino events for the region Nino 3.4

Vinod Kumar*1, K. S. Hosalikar2 and M. Satya Kumar3
1Shyam Bhawan, Road No.11, Ashok Nagar, Kankarbagh Colony, Patna-800020
2Regional Meteorological centre, India Meteorological Department, Colaba, Mumbai-400005
3H. No. 6-3-565, Flat No. 301, Akshaya Apartment, Somajiguda, Hyderabad-500082
*Corresponding Author: vinodmanjusingh@gmail.com

Meteorologists have observed that northern hemisphere (NH) is warmer than southern hemisphere (SH). It is well known that extra tropical low pressure system tends to move equator ward and eastward. Cold air coming from 40°S or from South of 40°S is restricted by persistent lows (negative anomalies of geo potential height at 850 hPa: extra tropical lows) located between 140°E - 080°W/30°S- 40°S during El Nino years. Coverage area of lows may be found to be more in the northern latitudes. Prominent low features may be observed from January-February onwards when three months average value of the Ocean Nino Index (ONI) starts increasing from lower to higher value during certain years. Presence of low is also reflected by associated circulation/trough observed at 850 hPa vector wind between 140°E - 080°W/30°S-40°S. Westerly component of wind can be observed prominently between 160°E - 080°W and 40°S - equator depending upon the position of lows. Subtropical highs (positive anomalies of geo potential height at 850 hPa) at 850 hPa, located between 140°E - 080°W/ 30°S - 40°S weaken and shift southwards, and extra tropical low pressure systems, located south of 40°S shift northwards from their position during El Nino years. The contrast feature is observed during La Nina years and many non El Nino years in the form of prominent highs, which are observed between 140°E-080°W/30°S-40°S and the coverage area may be found to be more in the northern latitudes. Similar feature can be observed in the form of anti cyclone or ridge at 850 vector winds. Easterly component of wind can be observed prominently between 160°E - 080°W and 40°S - equator depending upon the position of highs.
Nino 3.4 is 5°N-5°S/170°W-120°W
Key words: Geo potential height anomalies at 850 hPa, low, high, ONI, El-Nino and La Nina years.

Atmospheric reactive nitrogen fluxes and scavenging through wet deposition Over Mathura (India)

Mudita Chaturvedi, Reema Tiwari and Umesh Kulshrestha*
School of Environmental Sciences, Jawaharlal University, New Delhi 110067, India
*Corresponding Author: umeshkulshrestha@gmail.com

In the era of excessive use of fertilizer and combustion of fossil fuel, the atmospheric deposition of reactive nitrogen species has led to the problem of acidification and eutrophication of the ecosystem. This study has been carried out for estimating the concentrations and wet deposition fluxes of Nr species in rain water along with their scavenging behaviour at a typical residential site under semiarid tropical region. For this purpose, sequential sampling of a rain event was performed for determining Nr levels during monsoon 2015 period. Samples were analysed for their cationic and anionic content using an ion chromatograph. The results showed a relative abundance of NH4+ (62.3 ± 2.3 µeql-1) over NO3- (46.8 ± 40.1 µ eql-1) in the rain water samples, subsequently creating a higher wet deposition flux of NH4+-N (3.6 kg ha-1y-1) in comparison to NO3- -N (2.1 kg ha-1y-1). This clearly indicated that the Nr deposition had very significant contribution over the study area. Scavenging patterns confirmed the presence of NH4NO3 showing co-variations along with the rainfall intensity. A strong correlation (0.92) of NH4 and NO3 also supported such observations, thereby, confirming the dominant forms in which these Nr species are being deposited over the study area.
Nr: It represents NH4+ and NO3- in this paper
Key words: Reactive nitrogen, wet scavenging, rainfall intensity, neutralization capacity.

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