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41.
Shiv Jyoti Pandey G. M. Bhat Shveta Puri Neha Raina Yudhbir Singh S. K. Pandita Mithila Verma B. K. Bansal Anup Sutar 《Journal of Seismology》2017,21(3):525-538
Two moderate earthquakes of Mw 5.7 on the first of May and Mw 5.2 on the second of August occurred in the Kishtwar region in the year 2013. Our broadband seismic observatories located in the region recorded these events and the aftershocks. We analyzed these data to understand the seismotectonics of this region. Most of the events were located between 33.03° to 33.29° N latitude and 75.40° to 76.07° E longitude. Focal depths of these shallow earthquakes range from 7 to 12 km and are confined between Panjal Thrust (PT) and Kishtwar Window (KW). Spectral analysis of these events reveals that stress drop, source radius, corner frequency, and moment magnitude varied between 3.3 and 70.1 bars, 0.121 and 3.55 km, 0.397 and 6.06 Hz, and Mw 2.2 and Mw 5.7, respectively. The low stress drop of small-magnitude earthquakes reveals the brittle nature of the upper crust which is coincident with the field observations. The variation of stress drop with magnitude shows positive correlation whereas no such relation was observed between stress drop and depth of focus. The b value calculated (0.83) for the area reveals high stress accumulation within the incompetent rock zones in the area. 相似文献
42.
Natural Hazards - High wind poses a number of hazards in different areas such as structural safety, aviation, and wind energy—where low wind speed is also a concern, pollutant transport, to... 相似文献
43.
Mofazzal H. Khondekar Dipendra N. Ghosh Koushik Ghosh Anup Kumar Bhattacharya 《Astrophysics and Space Science》2012,342(2):287-301
In the present work an attempt has been made to investigate statistical association between solar neutrino flux data (both D2O and Salt data) collected from Sudbury Neutrino Observatory and solar irradiance data detected by Earth Radiation Budget Satellite. To serve the present purpose we have used the Multifractal Detrended Cross Correlation Analysis (MF-DCCA) based on Detrended Fluctuation Analysis (MF-X-DFA) method and the Detrending Moving Average Analysis (MF-X-DMA) which explores the long term power-law cross correlations between above two pairs of data sets. Investigation also has been made to find the frequency and time dependent local phase relationship in each pair of data sets using continuous wavelet transform (CWT) based Semblance Analysis. The Semblance Analysis reveals that there exists positive phase correlation as well as negative phase correlation between solar irradiance and D2O data at different time sub-intervals. This type of mixed phase correlation is also experienced between solar irradiance and Salt data at different time sub-intervals. The causal relationship between the D2O and the solar irradiance time series and that between Salt and solar irradiance time series have been revealed using Singular Spectral Analysis (SSA). Calculations indicate that possibly the present solar neutrino flux data (both D2O and Salt data) is supportive to predict the solar irradiance data but may not the vice versa which in turn suggests that the variability of nuclear energy generation process inside the Sun may influence the solar activity. 相似文献
44.
Arun K. Gupta Sumer Chopra Sanjay K. Prajapati Anup K. Sutar B. K. Bansal 《Natural Hazards》2013,68(2):405-417
In this study, we have prepared an intensity map based on macroseismic survey and all the available information from print and electronic media of damage and other effects due to March 05, 2012, M 4.9 Bahadurgarh (Haryana–Delhi border) earthquake and interpreted them to obtain modified Mercalli intensities (MMI) at over 62 locations surrounding the Haryana and Delhi. We have cross-checked the damage information from print and electronic media in the field at 25 sites within 110 km surrounding the epicenter for validation. Based on the questionnaire which is used in macroseismic survey and personal judgment, intensities were assigned accordingly as per physical survey at 25 sites and for rest based on media reporting. A maximum intensity of VI was assigned to this seismic event. Isoseismals of V and VI have been fully covered in the field observations. Beside this, some of the points have also been covered for isoseismal IV and isoseismal III and rest are based on media report only. The intensity map reveals several interesting features. Elliptically elongated shape of intensity map shows that most of the slightly damaged areas are concentrated toward the northwestern side of the epicenter having intensity V which may be due to directivity or site effects. A regression relation has also been derived between intensity and epicentral distance. The derived attenuation relation will be useful for assessing damage of a potential future earthquake (earthquake scenario–based planning purposes) for the Delhi NCR region. 相似文献
45.
Anup Saha Santimoy Kundu Shishir Gupta Pramod Kumar Vaishnav 《Journal of Earth System Science》2016,125(4):885-895
The present paper is concerned with the propagation of torsional surface waves in an initially stressed anisotropic porous layer sandwiched between homogeneous and non-homogeneous half-space. We assume the quadratic inhomogeneity in rigidity and density in the lower half-space and irregularity is taken in the form of rectangle at the interface separating the layer from the lower half-space. The dispersion equation for torsional waves has been obtained in a closed form. Velocity equation is also obtained in the absence of irregularity. The study reveals that the presence of irregularity, initial stress, porosity, inhomogeneity and anisotropy factor in the dispersion equation approves the significant effect of these parameters in the propagation of torsional waves in porous medium. It has also been observed that for a uniform media, the velocity equation reduces to the classical result of Love wave. 相似文献
46.
Ilmenite, Magnetite and Chromite Beach Placers from South Maharashtra, Central West Coast of India 总被引:1,自引:0,他引:1
Anup R. Gujar Nawso V. Ambre Premchand G. Mislankar Sridhar D. Iyer 《Resource Geology》2010,60(1):71-86
The heavy mineral placer deposits of the coastal sediments in south Maharashtra stretch for 12.5 km from Pirwadi in the north to Talashil in the south. The area is a sand bar represented by a narrow submergent coastal plain lying between the Achara and Gad Rivers. The sediments in the area are mainly sands which are moderately well sorted to well sorted. The heavy mineral concentration in the surficial sediments ranges between 0.69 and 98.32 wt % (28.73 wt % in average). The heavy mineral concentration shows an increasing trend from north to south. The heavy mineral suite consists predominantly of opaque minerals (ilmenite, magnetite and chromite), garnet, pyroxene, amphibole, zircon, tourmaline, rutile, staurolite, etc. Ilmenite grains are fresh whereas magnetite grains show the effect of weathering and alteration. The chromite grains are rounded to sub-rounded with alteration at the margin of the grains. The surficial textures of the opaque minerals show mechanical breaking that indicates limited distance of transportation. Ilmenite has TiO2 in the range between 40.04 and 46.6 wt %. Based on ore microscopy studies, the magnetite grains appear to be of two types: pure magnetite and titano-magnetite. Compositionally, the total magnetite fractions have Fe2O3 between 32 and 46 wt %, FeO between 19.0 and 25 wt % and TiO2 between 14.3 and 23.9 wt %. The chromite grains are an admixture of two varieties, ferro-chromite and magnesio-chromite. The chromite grains have 32.06–47.5 wt % of Cr2O3 with total iron between 23.86 wt % (4.73% Fe2O3 and 19.13% FeO) and 27.89 wt % (4.36% Fe2O3 and 23.53% FeO) and MgO between 12 and 40 wt %. The observed variations in the distribution of heavy minerals in the area are due to differences in the sediment supply, their specific gravity and oceanographic processes all of which result in a selective sorting of the sediments. The observed mineral assemblages of transparent heavy minerals (pyroxene, amphibole, tourmaline, kyanite, garnet, zircon and olivine) are suggestive of their derivation from a heterogeneous provenance comprising of igneous rocks, high grade metamorphic rocks and reworked Kaladgi sediments. The chromite grains appear to have been derived from ultrabasic rocks present in the upper reaches of the Gad River. The inferred reserves of ilmenite, magnetite and chromite are 0.175, 0.395 and 0.032 million tons, respectively. 相似文献
47.
Anup K. Prasad Lim Chai Ramesh P. Singh Menas Kafatos 《International Journal of Applied Earth Observation and Geoinformation》2006
Numerous efforts have been made to develop various indices using remote sensing data such as normalized difference vegetation index (NDVI), vegetation condition index (VCI) and temperature condition index (TCI) for mapping and monitoring of drought and assessment of vegetation health and productivity. NDVI, soil moisture, surface temperature and rainfall are valuable sources of information for the estimation and prediction of crop conditions. In the present paper, we have considered NDVI, soil moisture, surface temperature and rainfall data of Iowa state, US, for 19 years for crop yield assessment and prediction using piecewise linear regression method with breakpoint. Crop production environment consists of inherent sources of heterogeneity and their non-linear behavior. A non-linear Quasi-Newton multi-variate optimization method is utilized, which reasonably minimizes inconsistency and errors in yield prediction. 相似文献
48.
Anup K. Prasad Ramesh P. Singh Ashbindu Singh 《Journal of the Indian Society of Remote Sensing》2004,32(4):313-316
High AOD is observed over the Ganga basin throughout the year unlike southern India, is alarming as this basin is one of the
most productive basins of Indian subcontinent having population of more than 460 million. AOD is found to be increasing rapidly
since 2000 in summer season that may cause adverse effect to the agricultural crops and also to the human health. Increased
aerosol loading may likely affect the rainfall which is responsible for the observed drought conditions over the Indian subcontinent.
Detailed analysis of AOD, crop yields and rainfall data are required to understand the impact of increasing aerosol loading
over the Indian subcontinent. 相似文献
49.
K. Gopalan M.N. Rao K.M. Suthar T.R. Venkatesan 《Earth and Planetary Science Letters》1977,36(2):341-346
Whole rock and chondrules of the Dhajala chondrite were analyzed for Ne, Ar, Kr and Xe by total melting as well as by stepwise heating techniques. The cosmic ray exposure ages for the whole rock and the chondrules are6.2 ± 0.8 and6.3 ± 1.0m.y. as determined by the21Ne method and4.8 ± 1.5 and4.2 ± 2.0m.y. by the38Ar method, respectively. The K-Ar age of the whole rock is4.2 ± 0.4b.y. The elemental composition of the trapped gas in this chondrite is of “planetary” type. The radiogenic129Xe contents in the whole rock and chondrules are similar and this component is very retentively sited in the chondrules. 相似文献
50.
Drinking water quality in villages of southwestern Haryana,India: assessing human health risks associated with hydrochemistry 总被引:1,自引:0,他引:1
Vinod K. Garg Surindra Suthar Sushma Singh Aleenjeet Sheoran Garima Meenakshi Sandeep Jain 《Environmental Geology》2009,58(6):1329-1340
The chemical quality of groundwater of western Haryana, India was assessed for its suitability for drinking purposes. A total
of 275 water samples were collected from deep aquifer based hand-pumps situated in 37 different villages/towns of Bhiwani
region. The water samples were analyzed for different physico-chemical properties, e.g., pH, total dissolved solids (TDS),
total harness (TH), total alkalinity (TA), calcium, magnesium, carbonate, bicarbonate, sulphate, chloride and fluoride concentrations.
In this study, the average TDS content was greater ranging 1,692 (Bhiwani block) to 2,560 mg l−1 (Siwani block), and other important parameters of water, e.g., TA (442–1,232 mg l−1), TH (437–864 mg l−1) and bicarbonate (554–672 mg l−1), were also higher than maximum permissible limit by WHO or BIS. The fluoride appeared as a major problem of safe drinking
water in this region. We recorded greater fluoride concentration, i.e., 86.0 mg l−1 from Motipura village that is highest fluoride level ever recorded for Haryana state. The average fluoride concentration ranged between
7.1 and 0.8 mg l−1 in different blocks of western Haryana. On the basis of fluoride concentration, Siwani block showed the maximum number of water samples (84% of total collected samples) unsuitable for drinking purposes (containing
fluoride >1.5 mg l−1) followed by Charki Dadri block (58%), Bhiwani block (52%), Bawani Khera block (33%) and Loharu block (14%). This study clearly suggest that some health deteriorating chemicals in drinking water were at dangerous level and;
therefore, water quality could be a major health threat for local residents of western Haryana. The high fluoride level in
drinking water has posed some serious dental health risks in local residents. 相似文献