GNGTS 2013 - Atti del 32° Convegno Nazionale

Body Wave Attenuation of Kumaun Himalaya M.S. Chauhan 1 , A.R. Bansal 2 1 University of Naples “Federico II”, Naples, Italy 2 CSIR-National Geophysical Research Institute, Hyderabad, India Introduction. The Himalayan belt is formed due to the collision of Indian and Eurasian plates in the period 50-55 million years ago. This belt is seismically active and earthquake of varying magnitude are being observed. Most of these earthquakes are associated with great loss of life and destruction of property. For understanding of the nature of earthquakes and for reliable assessment of seismic risk in the Himalayan belt, knowledge and understanding of seismicity and the attenuation of strong ground motion are essential. Due to the vast natural resources in the Himalayan region, development of the region is being planned. For utilization of its resources major projects such as Tehri dam, Tunnels projects have been proposed. People living in this region are concerned about their survival due to the active seismicity of the region. In the light of the higher seismicity, an appraisal of the relation of earthquake occurrences with geology and tectonics of the region is very essential to make an assessment of the seismic potentialities, for survival of the lives and natural resources, and in designing of the major structures. The designing of earthquake resistant structures is a major challenge to the Civil Engineers. This challenge can be met if we develop ability to predict ground motion due to future earthquakes. The important structure such as nuclear power plants, dams, and high-rise buildings require estimate of ground motion for earthquake resistant designing. In the present work, we have made effort to understand the Body wave attenuation in Kumaun Himalaya using strong ground motion data (Kayal, 2008). Geology of the Kumaun Himalaya. Himalaya is a large geodynamic laboratory of nature where orogeny is still in youth to early mature phases of evolution. It is one of the most active orogens of the world and is the consequence of the collision of the Indian plate with the collage of previously sutured micro continental plates of central Asia during mid to late Eocene. The Kumaun region of the Himalaya lies near the center of the Himalayan fold-and-thrust belt and is situated between the Kali River in the east and Sutlej in the west, including a 320 km stretch of mountainous terrain. This part of Himalaya exposes all the four major litho-tectonic subdivisions of the Himalaya from South to North. They are Sub-Himalaya, Lesser Himalaya, Great Himalaya and Tethys Himalaya. All the litho-tectonic zones are bound on either side by longitudinally continuous tectonic surfaces such as Main Boundary Thrust (MBT), Main Central Thrust (MCT), South Tibetan Detachment (STD) system and Indus Tsangpo Suture Zone (ITSZ). The Sub-Himalaya includes the molassic Siwalik super group of Mio- References Dahlgren, P., 1995, Television and the Public Sphere. Citizenship, Democracy and the Media, London, Thousand Oaks & New Delhi, Sage. Goffman, E., 1959, The presentation of self in everyday life Garden City, Doubleday. Habermas, J., 1962, Strukturwandel der Öffentlichkheit, Darmstadt - Neuwied, Hermann LuchterhanhVerlag; en. The Structural Transformation of the Public Sphere: An Inquiry into a Category of Bourgeois Society, Cambridge, MA, MIT Press, 1989. Mazzoleni, G., 1995, Towards a ‘videocracy’? Italian political communication at a turning point, in «European Journal of Communication», 10, pp. 291-319. Mazzoleni, G. e Schulz, W., 1999, “Mediatization” of politics: A challenge for democracy?, in «Political Communication.», 16, pp. 247-261. Mazzoleni, G., Stewart, J. e Horsfield, B. (a cura di), 2003, The media and neo-populism. A contemporary comparative analysis, Westport, CT., Praeger Publishers. Nature, 2012, Shock and law, in «Nature», 490. Thompson, J.B., 1995 Media and Modernity: A Social Theory of the Media Cambridge, Polity Press; trad. it. Mezzi di comunicazione e modernità. Una teoria sociale dei media, Bologna, Il Mulino, 1998. 139 GNGTS 2013 S essione 1.1