January 2018

January, 2018   ||  Volume 22 No.1


My Fifty Years of Adventures Measuring Gravity and Gravity Gradients at Sea, In Airplanes, and by Astronauts, on the Moon

Manik Talwani
Rice University, Department of Earth Science-MS 126
Houston,Texas, 77005, U.S.A
*Corresponding Author: manik@rice.edu

Gravity measurements that generally require an accuracy of 1 milligal for regional studies and often 0.1 milligal for commercial investigations in the presence of Earth’s gravity of about 980,000 mgal are difficult to start with, even using apparatus placed on a fixed horizontal plane (1 milligal or mgal = .001cm/sec2). Moving platforms at sea, because of their obvious instability pose additional large problems in measuring gravity. Those problems and their solution are the subjects of this paper, which discusses various methods of measuring gravity at sea. I also describe how a gravity measuring instrument was constructed for use by astronauts on the moon. A particular emphasis is placed on how the errors in measurements caused by horizontal accelerations on moving vehicles were determined and eliminated. Finally, an instrument for measuring gravity gradients in airplanes, and its application in a survey are described.
Key words: Gravity and Gravity gradients, Moving platforms, Gravity measuring instruments, horizontal accelerations

Study of 2D Basins and Site-City Interaction Effects on Ground Motion Characteristics

Neeraj Kumar* and J.P. Narayan
Department of Earthquake Engineering, Indian Institute of Technology, Roorkee-247676
*Corresponding Author: neerajlohchab018@gmail.com

The rapid increase of population in Indian metro cities like Delhi has pressurized the builders to construct residential buildings and houses even at vulnerable sites like near the river beds, ponds etc. Many lakes and reclaimed lands are dumped with soil to create land for the construction purposes. In India, presently earthquake engineers are using 1D fundamental frequency (F01D) of sediment deposit in the designing of earthquake resistant structures. However, the closed basin may be 2D or 3D in nature and its fundamental frequency may not match the frequency predicted using 1D approach. In this paper, the numerically computed SH-wave fundamental frequency (F02D) of various considered 2D rectangular and elliptical basins is presented. Another, aim of our study is to present the effects of site-city-interaction (SCI) particulars on the building response when both the city and the basin are under double resonance condition. The analysis of simulated results revealed that F02D of basin increases with the increase of shape-ratio (ratio of the depth of basin to its half width). It is observed that the F02D of the basin is more than the F01D of that basin when shape-ratio is more than 0.25. The obtained F02D of the elliptical basin is larger than that of the rectangular basin for the same shape-ratio and other parameters. Furthermore, the value of the ratio of spectral amplifications at the F02D and F01D fundamental resonance frequencies is around 2.24 for the considered smallest basin and respective parameters. A new empirical relationship has been developed to predict the F02D of the elliptical basin. The results of SCI effects on the building response revealed an unexpected reduction of building response when both the city and basin are under double resonance condition.
Key words: 2D Basins response, Site-City Interaction, Viscoelastic FD algorithm, Double resonance.

A new Approach for Residual Gravity Anomalies Interpretations: Artificial Bee colony Optimization Algorithm

Ahmad Alvandi*1 and Rasoul Hoseini Asil2
1University of Applied Science and Technology, Hamedan Province Branch, Iran
2Young Researchers Club and Elites, Sahneh Branch, Islamic Azad University, Sahneh, Iran
*Corresponding Author: sim.alvandi@gmail.com 

In this paper, we applied a meta-heuristic algorithm in solving inverse problems in geophysics. Artificial bee colony optimization algorithm works based on probability, test and trial and it stems from honey bees in the nature. Such behavior in bees is closely similar to the inverse problems in geophysics for finding the actual/real parameters. Therefore, this idea is applied to solve an inverse problem. Firstly, the efficiency of this method is evaluated using synthetic model with and without random noise and after a theoretical verification, the procedure is applied to the field data from Ajichai salt dome, Iran. A very good agreement was observed/ revealed between the results obtained by the artificial bee colony algorithm and drilling information.
Key words: Bee Colony Algorithm, Gravity Data Inversion, Synthetic and Real Data, Salt Dome, Ajichai Area.

Application of Electrical Resistivity Imaging in investigation of Late Maastrichtian coal seam at Amoso Edda/Owutu Edda environs, Anambra Basin, Nigeria

Falae Philips Omowumi*1, Oyebamiji Abiola2 and Fadamoro Oluwafemi Festus3
1CSIR- Central Building Research Institute, CBRI, Roorkee, India
2Department of Science Laboratory Technology (Geology/Mining option),
Ekiti State University Ado-Ekiti, PMB-5363, Ado-Ekiti, Nigeria
3CSIR-Central Road Research Institute, CRRI, Delhi, India
*Corresponding Author: philomo08@gmail.com  

The coal exploration has been carried out using Electrical Resistivity imaging around Afikpo area of Southeastern Nigeria with the aim of delineating possible occurrence, depth to and thickness of coal seam. The results obtained from the interpretation of the VES identified four to seven lithologic units with varying depths and thicknesses, which include top soil, laterite, shale and coal seam. The thickness of the coal seam within the area ranges from 0.9-3.2m with an average of 2.05m, while average overburden thickness is estimated at 27.75m. Thin coal seams were delineated in few locations mostly in the central part and towards the NorthWestern side of the study area. Further drilling programme is recommended to estimate the total reserve of the resource coal available within the area. 
Key words: mineral resources, geophysics, coal seam.

Spatial mapping of aquifer parameters over basaltic terrain of Maharashtra (India) using geophysical and hydro-geochemical information

G. Shailaja1, G. Gupta*1 and P. Rama Rao2
1Indian Institute of Geomagnetism, New Panvel (W), Navi Mumbai 410218
2Department of Geophysics, Andhra University, Visakhapatnam 530 003
*Corresponding author: gupta_gautam1966@yahoo.co.in

Integrating the geoelectrical parameters with hydro-geochemical parameters of existing wells, the hydraulic conductivity, transmissivity and porosity of hard rock basaltic aquifers in a part of the semi-arid south-eastern region of Maharashtra were estimated. The hydraulic conductivity values were computed using the Kozeny–Carman–Bear (KCB) equation. The spatial variation of aquifer parameters was determined using the ordinary kriging technique. The results suggest that a number of isolated pockets of the study area reveal relatively high value of hydraulic conductivity, porosity and transmissivity. The hydraulic conductivity decreases with increasing bulk electrical resistivity due to possible presence of basaltic rock while, the increase of hydraulic conductivity with decrease of bulk electrical resistivity is presumably due to the good fracture network connectivity in crystalline hard rock.The transmissivity values at certain locations divulge high values (>380 m2/day), which are likely due to the water-saturated fractured medium. The derived transmissivity values are in good agreement with those obtained from well performance data of Central Ground Water Board (CGWB). These zones also have relatively high aquifer thickness and thus represent high potential regions within the water-bearing formations. The spatial variation map of transmissivity reveals a positive relationship with hydraulic conductivity at north-east, southern and western parts of the study area. These findings indicate that such studies would be useful in characterizing the aquifer system over different semi-arid, trap covered regions of India, including Maharashtra. 
Key words: Vertical electrical sounding, hydro-geochemical parameters, hydraulic conductivity, kriging technique, transmissivity, porosity, Deccan Volcanic Province.

Locating Center of Pressure in 2D Geological Situations

Soumyajit Mukherjee
Department of Earth Sciences, Indian Institute of Technology Bombay
Powai, Mumbai 400 076, Maharashtra, INDIA
*Corresponding Author: soumyajitm@gmail.com

Center of pressure (COP) for horizontal rock slices with realistic density distribution is presented. The location of the COP within the slab depends on the following parameters: (linear) density gradient, compaction constant, density of matrix and that of the pore fluid, and the length and width of the slab. However, no simple proportionality relation amongst the co-ordinates of the COP and these parameters exist. Vertical and thin rock layers such as sedimentary and igneous dykes with different (empirical) relations of spatial density variation can also be worked out in a similar way to locate their COPs.
Key words: Statics, porosity, density distribution, tectonics, structural geology.

Relative Index of Seismic Hazard (RISH) and it’s Implication in first order Seismic Hazard Assessment of Sabarmati River Basin, Gujarat, India

R.K. Dubey*1, Vinay K. Dwivedi2, Vasu Pancholi2 and B. K. Rastogi2
1Indian Institute of Technology (Indian School of Mines), Dhanbad-826 004
2Institute of Seismological Research, Raisan, Gandhinagar 382009, India
*Corresponding Author: rkdbhumin1085@yahoo.co.in

The paper emphasizes the application of geomorphic indices integrated with soil characteristics and groundwater level as a tool for first order seismic hazard assessment over a larger area to prepare policies regarding reduction in earthquakes induced impacts and damages to life, properties of people and ecology. For the purpose, Sabarmati River basin of the Gujarat mainland has been studied as the area had witnessed great damage during the 2001 Bhuj earthquake. The region of the Sabarmati River basin has been divided into eleven sub-basins. Each sub-basin has been analyzed in view of various geomorphic indices of active tectonics to delineate various seismotectonic elements in the area. These analysed elements in integration with the soil characteristics and groundwater conditions have been utilized to classify the region in various degrees of activeness in microseismic hazards considerations. Values of each studied parameter were grouped into four subclasses namely class 1: Inactive, class 2: less active, class 3: moderately active and class 4: active. These respective classes of each parameter were combined and averaged for formulation of a new parameter like “Relative Index of Seismic Hazard (RISH)”. The developed RISH values were used to define level of risk through four classes such as class 1: Relatively Low risk (RISH < 2.25), class 2: Low Risk (2.25 < RISH < 2.75), class 3: Moderate Risk (2.75 < RISH < 3.25) and class 4: High Risk (RISH > 3.25). The study finally reveals the distribution of area for different approximate classes such as class 1 covers 17.83 %, class 2 covers 8.59 %; class 3 covers 58.16 % and class 4 covers 15.42 %. The results obtained are in accordance with regional seismotectonic setup and seismicity of the area.
Key words: Seismic Hazard; Geomorphic Indices; Liquefaction Potential; Sabarmati River basin.

On the global aspects of the almost-antipodal symmetry on the Earth

Kovalyov, Mikhail*1, Kovalyov, Nickolas2 and Kovalyov, Selena3 
1University of Alberta, Edmonton, Canada,
2Indiana Aerospace University, Cebu, Philippines
3MLGU, Minsk, Belarus
*Corresponding author: mkovalyo@ualberta.ca

We discuss the manifestations of antipodal symmetry in Earth’s geology, geography and seismic/tectonic activity.
Key words: Symmetries on Earth surface, antipodal symmetry, seismic activity, tectonic activity.

Temporal variation of carbon dioxide and water vapor density over a station in west coast of Arabian Sea during sea breeze and land breeze

T. Dharmaraj*1, M.N.Patil1, Cini Sukumaran2, B.S.Murthy1, G.R. Chinthalu1, 
E. Chandrasekar4, M. Rajendran3 and Devendraa Siingh1

*1Indian Institute of Tropical Meteorology, Pune, India
2Central Water Commission, Gandhinagar, Ahemedabad, India
3Department of Civil Engineering, Annamalai University, India
4Research Scholar, Annamalai University, India
*Corresponding Author: dharam@tropmet.res.in

Carbon dioxide (CO2), water vapor (H2O), wind (speed and direction) and air temperature was measured at 5 m above ground level (AGL) on a micrometeorological tower (9 m height) over Goa (15021′ N, 73051′ E), India. The observations pertaining to summer monsoon (July – September) and post monsoon (October) season of 2002 were analyzed to study the effect of surface layer stability on the variation of CO2 and H2O concentrations. Based on the surface wind direction, the observations were separated for sea breeze and land breeze hrs, which show that during sea breeze times the CO2 concentration was decreasing and H2O concentration increasing and the opposite trend during land breeze.
Key words: CO2, water vapor, wind speed, atmospheric stability, sea breeze, land breeze.

Forecasting rainfall trend over Tamil Nadu during northeast monsoon

Vinod Kumar*1, M. Satya Kumar2 and K. S. Hosalikar3
1Shyam Bhawan, Road No.11, Ashok Nagar, Kankarbagh Colony, Patna-800020
2H. No. 6-3-565, Flat No. 301, Akshaya Apartment, Somajiguda, Hyderabad- 500082
3Regional Meteorological centre, India Met Department, Colaba, Mumbai-400005
*Corresponding Author: vinodmanjusingh@gmail.com

Normally south west monsoon starts withdrawing from northwest India from 1st September and by 15th October; it remains restricted to south peninsular states. For forecasting rainfall trend over Tamil Nadu during northeast monsoon, synoptic features from 11th September to 10th October have been considered. Anomaly of 850 hPa/1000 hPa geo potential height/vector wind/Sea surface temperature for the selected period, provides input for forecasting excess (+20% or more), normal (-19% to +19%) and deficient (-20% or less) rainfall over Tamil Nadu during ensuing northeast monsoon. Anti cyclone, ridge, cyclonic circulation, trough and Col region (cyclonic flow) between 05°-15°N along east and west coast of India help in feeding moisture over Tamil Nadu before the start of northeast monsoon for normal and excess rainfall. 
Key words: Northeast monsoon rainfall, Anomaly of 850/1000 hPa geo potential height, Wind vector, Relative humidity, Sea surface temperature and Tamil Nadu.

2016 Southwest Monsoon and Its Long Range Forecast

Onkari Prasad*1, O.P. Singh2 and K. Prasad3
143, Ritu Apartments, A-4 Paschim Vihar, New Delhi-110063
2 B44, First Floor, Parshvnath Paradise, Mohan Nagar,Ghaziabad (U.P.)-201007
3D-104, Seema Apartments, Sector 11, Dwarka, New Delhi-110085
*Corresponding Author: prasadonkari123@yahoo.in

With 3% below normal rainfall for India as a whole, 2016 southwest monsoon has gone in records as a normal monsoon. However, as per the data of daily, monthly and seasonal rainfall, 2016 monsoon was a weak monsoon: On daily basis, the rainfall, for India as a whole, was on the lower side of normal on 70(57%) days out of 122 days of the season (Jun:19, Jul:14, Aug:21 and Sep:16). The number of days with rainfall on the lower side of normal in four broad regions were: NW India, 75(61%)days (June:17, Jul:18, Aug:14 and Sept:26); NE India, 77(63%) days (June:24, July:15, Aug:25 and Sep:13); Central India, 66(54%) days (Jun:21, Jul:15, Aug:17 & Sep:13) and South Peninsula, 73(60%) days (Jun:11, Jul:20, Aug:26 and Sep:16). Except for the month of July when rainfall, for the country as a whole, was 7% above normal, rainfall was below normal by 11%, 9% and 3% in June, August and September respectively. Severe drought like conditions prevailed over North and Peninsular India in August and over Northwest India and south Peninsula in September. For the season as a whole, rainfall was 6% above normal over Central India, but it was below normal in NW India, NE India and South Peninsula by 5%, 8% and 11%, respectively. 
Above normal rainfall had been forecast for 2016 monsoon by India Meteorological Department (IMD) and also by ‘Skymet Weather’- a private forecaster. In contrast to these forecasts, 2016 monsoon had been foreshadowed as a weak monsoon by SIOCZ model. SIOCZ model forecast for country as a whole, was in ‘Useful’ category in June and September, bi-monthly periods of Jul+ Aug and Aug+ Sep and for season as a whole. At subdivision level, except for the month of July, the forecast was in ‘Useful’ category in the remaining three months, bimonthly periods as well as for the season as a whole. At district level, seasonal forecast was in ‘Useful’ category in the states of Andhra Pradesh, Telangana, Himachal Pradesh, Maharashtra and Goa. However, it was slightly below the ‘Useful’ category mark in the state of Tamilnadu. Development of different phases of 2016 SWM, performance of SIOCZ model forecast and updates are discussed.
Key words: Southwest monsoon, long range forecast, South Indian Ocean Convergence Zone model, intra-seasonal changes, forecast updates.

Irrigation in India and needed strategies for sustainable Development

Scientist- G (Retd); CSIR-NGRI, Hyderabad-500007, Telangana State, India.
Email: parvatarreddy@gmail.com

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