Assessment of Liquefaction Potential of the Sediments of Chandigarh Area     

G. C. Kandpal  K. K. Agarwal 《Journal of the Geological Society of India》2018,91(3):323-328

Assessment of the liquefaction potential is one of the important aspects for earthquake hazard assessment. Liquefaction in the sediments during earthquake events may cause significant ground deformation, which in turn, may lead to significant structural damages to civil or engineering structures, further leading to loss of life and property. Liquefaction in sediments occurs in specific geological and geoenvironmental conditions under the influence of a certain level of earthquake shaking.In this paper an assessment of the liquefaction potential of the sediments present in and around Chandigarh has been made. The sub-surface disposition and geotechnical properties of the sedimentary units mapped and depth wise probed by drilling 24 shallow boreholes prima facie indicates susceptibility of interlayed sequence to liquefaction. The conditioning factors and geoenvironmental conditions essential for occurrence of liquefaction have been integrated and analysed to determine potential areas for liquefaction around the Union Territory of Chandigarh with respect to different levels of ground acceleration values expected in the area due to earthquake events.  相似文献   

Carcinogenic and Non-carcinogenic Risk Assessment of Metals in Groundwater via Ingestion and Dermal Absorption Pathways for Children and Adults in Malwa Region of Punjab     

Vikas Duggal  Asha Rani 《Journal of the Geological Society of India》2018,92(2):187-194

The concentration of trace metals was measured in groundwater samples collected from Malwa region of Punjab, India. The samples were analyzed by using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). The results were compared with permissible limits prescribed by various health and environmental protection agencies. The concentrations of trace metals such as Mn, Se, Mo, Cd, Sb and Pb were higher than their respective permissible limits at some sampling sites. The total hazard index (HI_total) (summing the hazard index through ingestion and dermal routes) at all the sampling sites exceeded or nearing unity, indicating the presence of non-carcinogenic health effects from ingestion of groundwater and dermal contact with groundwater. The results reveal that the total excess lifetime cancer risk (ELCR_total) of metals exposure was in accordance with the acceptable lifetime risks for carcinogens in drinking water.  相似文献   

Neotectonic Activity from Karewa Sediments,Kashmir Himalaya,India     

K. K. Agarwal  R. A. Shah  H. Achyuthan  D. S. Singh  S. Srivastava  I. Khan 《Geotectonics》2018,52(1):88-99

Intermontane basin sedimentation occurred during Pliocene-Pleistocene in the Karewa Basin which formed after the continent-continent collision resulting in the formation of Himalayan orogenic belt around Eocene. These are elongated, narrow, thrust bounded basins which have formed during the late stages of orogeny. Situated at a height of 1700–1800 m above sea level, the Karewa basin received sediments because of ponding of a pre-existing river system and the tectonic movements along the Great Himalayan Ranges in the north and the Pir-Panjal ranges in the south along active faults. About 1300 m thick sediments of largely fluvio-lacustrine, glacio-fluvio-lacustrine and eolian origin are exposed having evidences of neotectonically formed structural features such as folds and faults. Folds are more prominent in the Lower Karewa formation (Hirpur Formation) while faults (mostly normal faults) are abundant in the Upper Karewas (Nagum Formation). Drainage in the area varies from dendritic to anastomosing to parallel. Anastomosing drainage suggests sudden decrease in gradient while presence of linear features such as faults and ridges is evident by parallel drainage. Study of morphometric parameters such as stream length (Lsm) and stream length ratios (RL), bifurcation ratio (Rb), drainage density (D), form factor (Rf), circularity ratio (Rc), and elongation ratio (Re) also indicate intense tectonic activity in the recent past.  相似文献   

Overturned jointed non-sheared granite block emplaced on sheared non-jointed Alum shale     

Agarwal  Amar  Lied  Philipp 《International Journal of Earth Sciences》2018,107(7):2463-2464

International Journal of Earth Sciences -  相似文献   

Geochemical alterations in surface waters of Govind Ballabh Pant Sagar,Northern Coalfield,India     

Anshumali  Manisha Rani  Sanjay Kumar Yadav  Ashish Kumar 《Environmental Earth Sciences》2014,71(7):3181-3193

Major ions showed high concentrations, ionic strength and chemical activity in the surface waters of Govind Ballabh Pant Sagar reservoir. Various geochemical ratios showed the dominance of silicate over carbonate weathering and major ions such as Na⁺ + K⁺ account for about 52 % of the cation budget. The high Na⁺ and K⁺ showed sedimentation of rock/coal particles consisting of highly weathered silicate minerals contributed by the discharge of mine water, fly ash mixing during transportation, etc. Further, Ca²⁺ + Mg²⁺/Na⁺ + K⁺ ratio was <1 (0.92) indicating the occurrence of silicate weathering in the reservoir catchment. The comparative assessment showed that the proportion of Ca²⁺ + Mg²⁺/Na⁺ + K⁺ tends to be lower along the coal mining belts compared to non-coal mining regions in the world. The Ca²⁺/SO₄ ^2? ratio <1 revealed not only H₂CO₃ but H₂SO₄ also acting as a source of protons for rock weathering. The cause underlying these differences can be related directly to geological substrate and anthropogenic activities.  相似文献   

Study of total electron content variations over equatorial and low latitude ionosphere during extreme solar minimum     

Kavita Sharma  R. S. Dabas  Sudha Ravindran 《Astrophysics and Space Science》2012,341(2):277-286

In recent years with the advancement in satellite based navigational applications, study of Total Electron Content (TEC) has gained significant importance. It is well known that due to dynamical behaviour of equatorial and low latitude ionosphere, the levels of ionization is relatively high herein. The sustained decrease in solar extreme ultraviolet radiations during the current minimum is greater than any in recent history. This gives us the opportunity to study the observations of global positioning system total electron content (GPS-TEC) dual frequency signals from the GPS satellites continuously recorded at Trivandrum (an equatorial station) and Delhi (a low latitude station) during the extremely low solar activity period from January 2007 to June 2009. This study illustrates the diurnal, seasonal and annual variations of TEC during the extended solar minimum period. This study also investigates the behaviour of daytime ionosphere around spring and autumn equinoxes at low solar activity period. The results clearly reveal the presence of equinoctial asymmetry which is more pronounced at equatorial station Trivandrum. The diurnal variation of TEC shows a short-lived day minimum which occurs between 0500 to 0600 LT at both the stations. Delhi TEC values show its steep increase and reach at its peak value between 1200 and 1400 LT, while at the equator the peak is broad and occurs around 1600 LT. Further, the daily maximum TEC ranges from about 5 to 40 TEC units at Trivandrum and about 10 to 40 TEC units at Delhi, which correspond to range delay variations of about 1 to 8 m at the GPS L1 frequency of 1.575 GHz. The Maximum values of TEC were observed during spring equinox rather than autumn equinox, showing presence of semi annual variation at both the locations. The minimum values of TEC were observed during the summer solstice at Trivandrum indicating the presence of winter anomaly at equatorial region while Delhi TEC values were minimum during winter solstice showing absence of winter anomaly. Also the TEC values at both the locations have been decreasing since 2007 onwards exhibit good positive correlation with solar activity.  相似文献   

Sorption of Cesium on Clay Colloids: Kinetic and Thermodynamic Studies     

R. Deepthi Rani  P. Sasidhar 《Aquatic Geochemistry》2012,18(4):281-296

Sorption of radionuclides onto stable colloids can significantly enhance their transport in groundwater. Batch adsorption studies were performed to evaluate the influence of various experimental parameters like initial pH, contact time, temperature and concentration of Na⁺ and Ca²⁺ ions on the sorption of Cs on clay. The sorption process is dependent on pH of the solution with distribution coefficient (K _d) found to increase with increase in pH. The kinetic experiments were carried out at different temperatures, and the results have shown that the sorption process fits well into a pseudo-second-order mechanism with apparent activation energy of 45.7?kJ/mol. The rate constant was found to decrease with increase in temperature. The thermodynamic parameters such as ?G ⁰, ?H ⁰ and ?S ⁰ were calculated. The negative value of ?H ⁰ indicates that the reaction is exothermic. The negative values obtained for ?G ⁰ indicated that the sorption of cesium on clay was spontaneous at all studied concentrations. The distribution coefficient was found to decrease with increasing concentration of Na⁺ and Ca²⁺ ions. The cesium sorption data were fitted to Freundlich, Langmuir, Temkin and Dubinin–Radushkevich (D–R) isotherms. The values of Langmuir separation factor (R _L) indicate a favorable Cs adsorption. The values of mean free energy of sorption (E) at various temperatures ranged from 10.5 to 11.1?kJ/mol, which indicates that the sorption process follows chemisorption.  相似文献   

Correlation of geological terrane boundaries with lineaments interpreted from remote sensing data for Doddaballapur-Kolar Area, Eastern Dharwar Craton     

Nisha Rani 《Journal of the Geological Society of India》2012,80(5):743-743

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Simulated Heat Content Variability in the Upper Layers of the Tropical Indian Ocean     

Imran M. Momin  Neeraj Agarwal  Rashmi Sharma  Neetu  Sujit Basu  Abhijit Sarkar 《Marine Geodesy》2013,36(1):66-81

Ocean General Circulation Model (OGCM) simulations from 1970–2007 are used to study the upper ocean heat content variability in the Tropical Indian Ocean (TIO). Model computed heat contents up to 50 m (denoted by HC50 m hereafter) representing upper ocean heat content and 300 m (HC300 m) representing heat content up to thermocline depth are first compared with heat contents computed from observations of two buoys in the TIO. It is found that there is good agreement between the model and observations. Fourier analysis of heat content is carried out in different regions of TIO. The amplitudes of semi-annual variability for HC50 m and HC300 m are observed to be greater than those for the annual variability in the Bay of Bengal, while in the Arabian Sea there is a mixed result. Heat content tendency is known to be governed by net surface heat flux and horizontal as well as vertical heat transports. For understanding the relative importance of these processes, a detailed analysis of these terms in the tendency equation is carried out. Rossby wave is observed in the annual mode of heat transport while equatorial jet and Kelvin waves are observed in the semi-annual mode of heart transport. Finally, the correlation between heat content and sea surface temperature (SST) and sea level anomaly (SLA), taken one at a time, is computed. It is found that the correlation improves significantly when both these quantities are together taken into account.  相似文献   

Analysis of aerosol and carbon monoxide characteristics over Arabian Sea during crop residue burning period in the Indo-Gangetic Plains using multi-satellite remote sensing datasets     

K.V.S. Badarinath  Shailesh Kumar Kharol  Anu Rani Sharma  V. Krishna Prasad 《Journal of Atmospheric and Solar》2009,71(12):1267-1276

In this study, we have used multi-satellite data to retrieve aerosol loadings and carbon monoxide (CO) pollution over the Arabian Sea, caused due to anthropogenic activities over the Indo-Gangetic Plains (IGP) in India. Relatively high aerosol and CO loadings during 9–14 November 2007 over Arabian Sea were attributed to crop residues burning in the IGP and fireworks during Diwali festival. Aerosol index (AI) obtained from ozone monitoring instrument (OMI) and CO from measurements of pollution in the troposphere instrument (MOPITT). CO showed higher values over the Arabian Sea suggesting long-range transport of anthropogenic aerosols and trace gases from the continental to Arabian Sea region.  相似文献