Refine your search
Co-Authors
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z All
Mehta, Manish
- Monitoring of Glacier Changes and Response Time in Chorabari Glacier, Central Himalaya, Garhwal, India
Abstract Views :227 |
PDF Views:129
Authors
Affiliations
1 Centre for Glaciology, Wadia Institute of Himalayan Geology, Dehra Dun 248 001, IN
1 Centre for Glaciology, Wadia Institute of Himalayan Geology, Dehra Dun 248 001, IN
Source
Current Science, Vol 107, No 2 (2014), Pagination: 281-289Abstract
Chorabari Glacier (6.6 sq. km) in the Mandakini River basin, a tributary of the River Alaknanda, Central Himalaya, Garhwal (India) has been monitored in terms of its length and frontal area (snout) changes for the period between 1962 and 2012. Global Positioning System, Survey of India toposheet (1 : 50,000) and ground-based measurements were used to obtain the changes in morphology and size of the glacier. The result shows that the frontal area of the glacier has shrunk by 1% and 344 ± 24 m length loss, with an average rate of 6.8 ± 0.5 m a-1 from 1962 to 2012. The observed terminus records of Chorabari Glacier indicate that the positive mass balance can cause terminus advance in about a 17-year timescale. The lag time of glacier signal transferred from accumulation area to the snout by glacier flow is about 562 years. These observations as well as other studies carried out in the region show a significant reduction in glacier area. The increased retreat rate of the glacier snout is probably a direct consequence of global warming.Keywords
Frontal Areas, Glacier Change, Mass Balance, Response Time, Snout Retreat.Full Text
- New Occurrence of Albitite from Nubra Valley, Ladakh:Characterization from Mineralogy and Whole Rock Geochemistry
Abstract Views :198 |
PDF Views:76
Authors
Aditya Kharya
1,
H. K. Sachan
1,
Sameer K. Tiwari
1,
Saurabh Singhal
1,
P. Chandra Singh
1,
Santosh Rai
1,
Sushil Kumar
1,
Manish Mehta
1,
P. K. R. Gautam
1
Affiliations
1 Wadia Institute of Himalayan Geology, Dehra Dun 248 001, IN
1 Wadia Institute of Himalayan Geology, Dehra Dun 248 001, IN
Source
Current Science, Vol 111, No 9 (2016), Pagination: 1531-1535Abstract
We report here the occurrence of albitite in Nubra valley of Ladakh region in the Trans-Himalaya area within Indian Territory at 344446N and 77338E before Panamik (in the Wish Pond, local name of the area). The albitite has been characterized by petrography, mineral chemistry, X-ray diffraction and whole rock geochemistry (i.e. major, trace and rare earth elements (REE)). The albitite comprises 85-96% albite and amphibole, whereas apatite, zircon and ilmenite occur as accessory minerals. The textural relationship and geochemical data indicate its igneous origin. The albitite contains about 5-6 ppm U and Th which may possibly host U-REE mineralization.Keywords
Albitite, Karakoram, Mineral Chemistry, XRD, Whole Rock Chemistry.Full Text
References
- Ray, S. K., The albitite line of northern rajasthan – a fossil intracontinental rift-zone. J. Geol. Soc. India, 1990, 36, 413–423.
- Fareedudin and Bose, U., A new occurrence of albitite dyke near Arath, Nagaur district, Rajasthan. Curr. Sci., 1992, 62, 635–636.
- Yadav, G. S., Muthamilselvan, A., Shaji, T. S., Nanda, L. K. and Rai, A. K., Recognition of a new albitite zone in northern Rajasthan: its implications on uranium mineralization. Curr. Sci., 2015, 108, 1994–1998.
- Barbier, M., Caggianelli, A., Di Florio, M. and Lorenzoni, S., Plagiogranites and gabbroic rocks from the mingora ophiolitic mélange, swat valley, NW Frontier Province, Pakistan. Mineral. Mag., 1994, 58, 553–566.
- Srimal, N., India-asia collision: implications from the geology of the eastern Karakoram. Geology, 1986, 14, 523–527.
- Thakur, V. and Misra, D., Tectonic framework of the Indus and Shyok suture zones in Eastern Ladakh, Northwest Himalaya. Tectonophysics, 1984, 101, 207–220.
- Weinberg, R. F., Dunlap, W. J. and Whitehouse, M., New field, structural and geochronological data from the Shyok and Nubra valleys, Northern Ladakh: Linking Kohistan to Tibet. Tectonics of the Nanga Parbat Syntaxis and the Western Himalaya, 2000, 170, 253–275.
- Schwartz, M. O., Geochemical criteria for distinguishing magmatic and metasomatic albite-enrichment in granitoids – examples from the Ta-Li granite Yichun (China) and the Sn-W deposit tikus (Indonesia). Miner. Deposita, 1992, 27, 101–108.
- Smith, J. V., Feldspar minerals. Tom 2. Chemical and Textural Properties, Springer-Verlag, Berlin, 1974.
- Harlov, D., Tropper, P., Seifert, W., Nijland, T. and Förster, H.-J., Formation of al-rich titanite (catisio 4 o–caalsio 4 oh) reaction rims on ilmenite in metamorphic rocks as a function of fh 2 o and fo 2. Lithos, 2006, 88, 72–84.
- Leake, B., Nomenclature of amphiboles: report of the subcommittee on amphiboles of the international mineralogical association, commission on new minerals and mineral names. Can. Mineral., 1997, 35, 219–246.
- Saini, N., Mukherjee, P., Rathi, M., Khanna, P. and Purohit, K., A new geochemical reference sample of granite (dg-h) from Dalhousie, Himachal Himalaya. Geol. Soc. India, 1998, 52, 603–606.
- Khanna, P. P., Saini, N. K., Mukherjee, P. K. and Purohit, K. K., An appraisal of icp-ms technique for determination of rees: Long term qc assessment of silicate rock analysis. Himal. Geol., 2009, 30, 95–99.
- Boulvais, P., Ruffet, G., Cornichet, J. and Mermet, M., Cretaceous albitization and dequartzification of hercynian peraluminous granite in the salvezines massif (French pyrénées). Lithos, 2007, 93, 89–106.
- Castorina, F., Masi, U., Padalino, G. and Palomba, M., Constraints from geochemistry and Sr–Nd isotopes for the origin of albitite deposits from Central Sardinia (Italy). Miner. Deposita, 2006, 41, 323–338.
- Mohammad, Y. O., Maekawa, H. and Lawa, F. A., Mineralogy and origin of mlakawa albitite from Kurdistan region, Northeastern Iraq. Geosphere, 2007, 3, 624–645.
- Shand, S. J., Eruptive Rocks: Their Genesis, Composition, John Wiley, New York, 1943.
- Kaur, G. and Mehta, P., The gothara plagiogranite: evidence for oceanic magmatism in a non-ophiolitic association, north Khetri copper belt, Rajasthan, India? J. Asian Earth Sci., 2005, 25, 805–819.
- Miyashiro, A., Nature of alkalic volcanic rock series. Contrib. Mineral. Petrol., 1978, 66, 91–104.
- Le Bas, M., Ultra-alkaline magmatism with or without rifting. Tectonophysics, 1987, 143, 75–84.
- Modelling of Meteorological Parameters for the Chorabari Glacier Valley, Central Himalaya, India
Abstract Views :226 |
PDF Views:72
Authors
Affiliations
1 Centre for Glaciology, Wadia Institute of Himalayan Geology, Dehradun 248 001, IN
2 Wadia Institute of Himalayan Geology, Dehradun 248 001, IN
1 Centre for Glaciology, Wadia Institute of Himalayan Geology, Dehradun 248 001, IN
2 Wadia Institute of Himalayan Geology, Dehradun 248 001, IN
Source
Current Science, Vol 112, No 07 (2017), Pagination: 1553-1560Abstract
In the present study, we have developed empirical relationships to estimate meteorological parameters at the glacier altitude from the data on non-glacier altitude. Meteorological data collected from automatic weather station at Chorabari Glacier from November 2011 to May 2013 are analysed and empirical equations for air temperature, relative humidity and incoming global radiation are proposed. The dataset of one year (November 2011-October 2012) is used in the calibration of models, while data for the next seven months (November 2012-May 2013) are employed to validate the models. Moreover, an analytical study is also conducted on incoming diffuse radiation (estimated through the established model for India). Further, a relationship is established to correlate the diffuse component of two sites. Variation trend of meteorological parameters with altitude is found to be different for each of the parameters, viz. quadratic for air temperature, logarithmic for relative humidity, and linear for global and diffuse radiation. Performance of the generated equations is tested through various statistical methods. The study reveals that developed correlations are able to give a good match with in situ measurements.Keywords
Clearness Index, Empirical Models, Global and Diffuse Radiation, Meteorology.Full Text
References
- Houghton, J. T. et al., Climate change 2001: the Scientific Basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge, 2001.
- Bolch, T. et al., The state and fate of Himalayan glaciers. Science, 2012, 336(6079), 310–314.
- Karakoti, I., Kesarwani, K., Mehta, M. and Dobhal, D. P., Extended T-index models for glacier surface melting. Theor. Appl. Climatol., 2016; doi:10.1007/s00704-016-1753-6.
- Mehta, M., Dobhal, D. P., Kesarwani, K., Pratap, B., Kumar, A. and Verma, A., Monitoring of glacier changes and response time in Chorabari Glacier, Central Himalaya, Garhwal, India. Curr. Sci., 2014, 107(2), 281–289.
- Zemp, M., Hoelzle, M. and Haeberli, W., Six decades of glacier mass balance observations: a review of the worldwide monitoring network. Ann. Glaciol., 2009, 50, 101–111.
- Kesarwani, K., Dobhal, D. P., Durgapal, A. and Mehta, M., High altitude meteorology and cloud cover conditions: a study from Chorabari glacier catchment, Central Himalaya, India. Himalayan Geol., 2015, 36(2), 134–142.
- Kesarwani, K., Dobhal, D. P., Durgapal, A., Karakoti, I. and Mehta, M., Surface energy and mass balance on the ablation zone of Chorabari Glacier, Central Himalaya, India. In Geostatistical and Geospatial Approaches for the Characterization of Natural Resources in the Environment: Challenges, Processes and Strategies (ed. Raju, N. J.), Springer, 2016, pp. 881–885; doi:10.1007/978-3-319-18663-4_136.
- Overlemans, J., Glaciers and Climate Change. Balkema, Lisse, 2001.
- Kuhn, M, Climate and Glaciers, IAHS Publications, 1981, vol. 131, pp. 3–20.
- Schöner, W., Auer, I. and Bohm, R., Climate variability and glacier reaction in the Austrian eastern Alps. Ann. Glaciol., 2000, 31(1), 31–38.
- Greene, A. M., A time constant for hemisphere glacier mass balance. J. Glaciol., 2005, 51(174), 353–362.
- Greuell, W. and Smeets, C. J. J. P., Variations with elevation in the surface energy balance on the Pasterze (Austria). J. Geophys. Res., 2001, 106, 31717–31727.
- Kulkarni, A. V., Mass balance of Himalayan glacier using AAR and ELA methods. J. Glaciol., 1992, 38, 101–104.
- Kargel, J. S. et al., Multispectral imaging contributions to global land ice measurements from space. Remote Sensing Environ., 2005, 99, 187–219.
- Berthier, E., Arnaud, Y., Kumar, R., Ahmed, S., Wagon, P. and Chevallier, P., Remote sensing estimates of glacier mass balances in the Himachal Pradesh (Western Himalaya, India). Remote Sensing Environ., 2007, 108(3), 327–338.
- Dobhal, D. P., Gergan, J. T. and Thayyen, R. J., Mass balance studies of Dokriani glacier from 1992 to 2000, Garhwal Himalaya, India. Bull. Glaciol. Res., 2008, 25, 9–17.
- Bhambri, R. and Bolch, T., Glacier mapping: a review with special reference to the Indian Himalayas. Prog. Phys. Geogr., 2009, 33(5), 672–704.
- Das, S. K., Dobhal, D. P. and Juyal, N., Variability of aerosol optical depth and recent recessional trend in Dokriani Glacier, Bhagirathi Valley, Garhwal Himalaya. Curr. Sci., 2010, 99(12), 1816–1821.
- Bhambri, R., Bolch, T., Chaujar, R. K. and Kulshreshtha, S. C., Glacier changes in the Garhwal Himalaya, India, from 1968 to 2006 based on remote sensing. J. Glaciol., 2011, 57(203), 543–556.
- Mehta, M., Majeed, Z., Dobhal, D. P. and Srivastava, P., Geomorphological evidences of post-LGM glacial advancements in the Himalaya: a study from Chorabari Glacier, Garhwal Himalaya, India. J. Earth Syst. Sci., 2012, 121(1), 149–163.
- Kesarwani, K. et al., Meteorological observations at Chorabari and Dokriani glaciers, Garhwal Himalaya, India. J. Indian Geol. Cong., 2012, 1, 125–128.
- Bhambri, R., Bolch, T. Y., Kawishwar, P., Dobhal, D. P., Srivastava, D. and Pratap, B., Heterogeneity in glacier response in the upper Shyok valley, northeast Karakoram. Cryosphere, 2013, 7, 1385–1398; doi:10.5194/tc-7-1385-2013.
- Dobhal, D. P., Mehta, M. and Srivastava, D., Influence of debris cover on terminus retreat and mass changes of Chorabari Glacier, Garhwal region, central Himalaya, India. J. Glaciol., 2013, 59(217), 961–971; doi:10.3189/2013JoG12J180.
- Negi, H. S., Saravana, G., Rout, R. and Snehmani, Monitoring of great Himalayan glaciers in Patsio region, India using remote sensing and climatic observations. Curr. Sci., 2013, 105(10), 25.
- Azam, M. F., Wagon, P., Vincent, C., Ramanathan, A., Linda, A. and Singh, V. B., Reconstruction of the annual balance of Chhota Shigri glacier, Western Himalaya, India, since 1969. Ann. Glaciol., 2014, 55(66), doi:3189/2014AoG66A104.
- Bahuguna, I. M. et al., Are the Himalayan glaciers retreating? Curr. Sci., 2014, 106(7,10), 1008–1013.
- Baral, P. et al., Preliminary results of mass-balance observations of Yala Glacier and analysis of temperature and precipitation gradients in Langtang Valley, Nepal. Ann. Glaciol., 2014, 55(66); doi:10.3189/2014AoG66A106.
- Pratap, B., Dobhal, D. P., Mehta, M. and Bhambri, R., Influence of debris cover and altitude on glacier surface melting: a case study on Dokriani Glacier, central Himalaya, India. Ann. Glaciol., 2015, 56(70); doi:10.3189/2015AoG70A971.
- Karakoti, I., Das, P. K. and Singh, S. K., Predicting monthly mean daily diffuse radiation for India. Appl. Energy, 2012, 91, 412–425.
- Valdiya, K. S., Paul, S. K. and Chandra, T., Tectonic and lithological characterization of Himadri (Great Himalaya) between Kali and Yamuna rivers, Central Himalaya. Himalayan Geol., 1999, 20, 1–17.
- Iqbal, M., An Introduction to Solar Radiation, Academic Press, New York, London, 1983.
- Enhancement the Gain of Micro Strip Patch Antenna Using Array Configuration Technique
Abstract Views :151 |
PDF Views:4
Authors
Neeraj Rani
1,
Manish Mehta
1
Affiliations
1 Jan Nayak Ch. Devi Lal College of Engineering and Technology, Sirsa, Haryana, IN
1 Jan Nayak Ch. Devi Lal College of Engineering and Technology, Sirsa, Haryana, IN
Source
International Journal of Innovative Research and Development, Vol 5, No 9 (2016), Pagination: 186-191Abstract
A method to enhance the gain of micro strip patch antenna is investigated by array configuration technique. Array configuration technique improves the gain of micro strip patch antenna by increasing the effective aperture area. The effect of array configuration technique in different configurations has been studied numerically and validated experimentally. It is observed that with increase in effective aperture area, the gain of micro strip patch antenna is increased. A technique to increase the effective aperture area is place a number of patches on single dielectric substrate. Compared to single patch antenna, a double patch antenna provides high gain.
Keywords
Micro Strip Patch Antenna, Array, Gain, Return Loss.Full Text
- Causes and Consequences of Rishiganga Flash Flood, Nanda Devi Biosphere Reserve, Central Himalaya, India
Abstract Views :177 |
PDF Views:88
Authors
Affiliations
1 Wadia Institute of Himalayan Geology, Dehradun 248 001, IN
1 Wadia Institute of Himalayan Geology, Dehradun 248 001, IN
Source
Current Science, Vol 121, No 11 (2021), Pagination: 1483-1487Abstract
On 7 February 2021 at 10:30 am, a huge amount of slurry material flooded the Rishiganga catchment, resulting in excessive flow along the valley. The main cause of this flood was the dislocation of a huge rock mass approximately 540 m wide and 720 m long from the main rock body, which slipped down towards the Raunthi Gadera valley floor, causing massive devastation in the areas such as Raini, Tapovan, and Vishnuprayag. This event was not expected and was the first event in history when a flash flood occurred in winter. In this study, we tried to answer two major questions which are not been explained so far that are related to this disaster. These questions are (i) why did this event occur in winters? (ii) where did so much debris and water come from?. This study clearly answers these questions based on field observationsKeywords
Flash Flood, Himalaya, Nanda Devi, Raunthi Gadera, Rishiganga.Full Text
References
- Mehta, M., Shukla, T., Bhambri, R., Gupta, A. K. and Dobhal, D.
- P., Terrain changes, caused by the 15–17 June 2013 heavy rainfall in the Garhwal Himalaya, India: a case study of Alaknanda and Mandakini basins. Geomorphology, 2017, 284, 53–71.
- Valdiya, K. S., Paul, S. K., Tara, C., Bhakuni, S. S. and Upadhyay, R. C., Tectonic and lithological characterization of Himadri (Great Himalaya) between Kali and Yamuna rivers, Central Himalaya. Himalayan Geol., 1999, 20, 1–17.
- Dobhal, D. P., Gupta, A. K., Mehta, M. and Khandelwal, D. D., Kedarnath disaster: facts and plausible causes. Curr. Sci., 2013, 105(2), 171–174.
- Stocker, T. F. et al. (eds), Climate Change: The Physical Science Basis, Cambridge University Press, 2013, p. 1535.
- https://economictimes.indiatimes.com/news/india/uttarakhand-disasterdeath-toll-rises-to-77with-recovery-of-one-more-body-inrainivillage/articleshow/81673664.cms (accessed on 24 March 2021).
- Kumar, V., Shukla, T., Mehta, M., Dobhal, D. P., Bisht, M. P. S. and Nautiyal, S., Glacier changes and associated climate drivers for the last three decades, Nanda Devi region, Central Himalaya, India. Quaternary Int., 2021, 575–576, 213–226.
- Maruo, Y., Geology and metamorphism of the Nanda Devi region, Kumaun Higher Himalaya. Himalayan Geol., 1979, 9, 1–17.
- https://ms-my.facebook.com/NPIglaciology/posts/1449028428604128 (accessed on 2020).
- Harris, I., Osborn, T. J., Jones, P. and Lister, D., Version 4 of the CRU TS monthly high-resolution gridded multivariate climate dataset. Sci. Data, 2020, 7(109), 1–18; doi:10.1038/s41597-020-0453-3.
- Sinha, A. K., Geology of the Higher Central Himalaya, John Wiley, Chichester, UK, 1989, p. 236.
- Sain, K. et al., A perspective on Rishiganga–Dhauliganga flash flood in the Nanda Devi Biosphere Reserve, Garhwal Himalaya, India. J. Geol. Soc. India, 2021, 97, 335–338.
- Shugar, D. H. et al., A massive rock and ice avalanche caused the 2021 disaster at Chamoli, Indian Himalaya. Science, 2021, 373, 300–306.
- Agarwal, A. and Chak, A. (eds), Floods, Flood Plains and Environmental Myths, State of India Environments: A Citizen’s Report, Centre for Science and Environment, 1991, vol. 3, p. 167.
- Wasson, R. J., Sundriyal, Y. P., Chaudhary, S., Jaiswal, M. K., Morthekai, P., Sati, S. P. and Juyal, N., A 1000-year history of large floods in the Upper Ganga catchment, central Himalaya, India. Quaternary Sci. Rev., 2013, 77, 156–166.
- https://www.nationalheraldindia.com/india/uttarakhand-disaster-55bodies-recovered-so-far-179-missing-person-reports-lodged (accessed on 15 February 2021).
- https://timesofindia.indiatimes.com/india/uttarakhand-glacier-burstinchamoli-damages-hydropower-plant-rescue-operations-underway/ articleshow/80732809.cms (accessed on 7 February 2021).