<Emphasis Type="Bold">Petrography and Mineral Chemistry of Neovolcanics Occurring between Pacific and Nazca Plate Boundaries</Emphasis> by S.K. Pandey,J.P. Shrivastava and G.S. Roonwal. Jour. Geol. Soc. India,v.74, 2009, pp.559–572.     

S. K. Pandey  J. P. Shrivastava  G. S. Roonwal 《Journal of the Geological Society of India》2010,75(2):441-442

Discussion

Petrography and Mineral Chemistry of Neovolcanics Occurring between Pacific and Nazca Plate Boundaries by S.K. Pandey, J.P. Shrivastava and G.S. Roonwal. Jour. Geol. Soc. India, v.74, 2009, pp.559–572.  相似文献   

Weathering and Geochemical Processes Controlling Solute Acquisition in Ganga Headwater–Bhagirathi River, Garhwal Himalaya, India     

Shiv Kumar Pandey  Abhay Kumar Singh  S. I. Hasnain 《Aquatic Geochemistry》1999,5(4):357-379

Water and suspended sediment samples were collected along a longitudinal transect of the Bhagirathi – a headwater stream of the river Ganga, during the premonsoon and postmonsoon seasons, in order to assess the solute acquisition processes and sediment transfer in a high elevation river basin. Study results show that surface waters were dominated by HCO₃ and SO₄ in anionic abundance and Ca in cationic concentrations. A high concentration of sulphate in the source region indicates oxidative weathering of sulphide bearing minerals in the drainage basin. The combination of high concentrations of calcium, bicarbonate and sulphate in river water suggests that coupled reaction involving sulphide oxidation and carbonate dissolution are mainly controlling the solute acquisition processes in the drainage basin. The sediment transfer reveals that glacial weathering and erosion is the major influence on sediment production and transfer. The seasonal and spatial variation in ionic concentration, in general, is related to discharge and lithology. The sediment mineralogy and water mineral equilibrium indicate that water composition is in equilibrium with kaolinite. The river Bhagirathi annually delivers 0.74 M.tons of dissolved and 7.88 M.tons of suspended load to the river Ganga at Devprayag. The chemical and physical denudation rate of the Bhagirathi is 95 and 1010 tons/km²/yr, higher than the Indian and global average.  相似文献   

Assimilation of TOPEX Altimeter Data in a Reduced-Gravity Model of the Northwestern Indian Ocean     

Sujit Basu  Raj Kumar  R. M. Gairola  P. C. Pandey 《Marine Geodesy》1999,22(3):143-155

This study deals with the assimilation of TOPEX altimeter-derived sea level variability in a reduced-gravity model of the northwestern Indian Ocean. The assimilation has been done using variational assimilation method with adjoint technique. A cost function representing the misfit between the model and the data is minimized with the model equations acting as constraints. The initial conditions of the model are used as control parameters and the best-fit initial conditions are determined as a result of minimization carried out using a variable-storage quasi-Newton method. Experiment has been done with 10 days' cycle-averaged data of TOPEX. Assimilation for 10 days and 20 days has been performed and it has been seen that 20 days' assimilation of satellite data provides better results.  相似文献   

Seismotectonic study of Kishtwar region of Jammu Province using local broadband seismic data     

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   

Simulation of strong ground motion for a potential Mw7.3 earthquake in Kopili fault zone,northeast India     

Sutar  Anup K.  Verma  Mithila  Bansal  Brijesh K.  Pandey  Ajeet P. 《Natural Hazards》2020,100(1):437-457

Natural Hazards - The occurrence of major natural disasters in recent years has impacted large cities worldwide and boosted the need of assessing urban resilience. As a key factor of resilience,...  相似文献