%0 Journal Article
%T Seismic Hazard of the Uttarakhand Himalaya, India, from Deterministic Modeling of Possible Rupture Planes in the Area
%A Anand Joshi
%A Ashvini Kumar
%A Heriberta Castanos
%A Cinna Lomnitz
%J International Journal of Geophysics
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/825276
%X This paper presents use of semiempirical method for seismic hazard zonation. The seismotectonically important region of Uttarakhand Himalaya has been considered in this work. Ruptures along the lineaments in the area identified from tectonic map are modeled deterministically using semi empirical approach given by Midorikawa (1993). This approach makes use of attenuation relation of peak ground acceleration for simulating strong ground motion at any site. Strong motion data collected over a span of three years in this region have been used to develop attenuation relation of peak ground acceleration of limited magnitude and distance applicability. The developed attenuation relation is used in the semi empirical method to predict peak ground acceleration from the modeled rupture planes in the area. A set of values of peak ground acceleration from possible ruptures in the area at the point of investigation is further used to compute probability of exceedance of peak ground acceleration of values 100 and 200 gals. The prepared map shows that regions like Tehri, Chamoli, Almora, Srinagar, Devprayag, Bageshwar, and Pauri fall in a zone of 10% probability of exceedence of peak ground acceleration of value 200 gals. 1. Introduction Estimation of seismic hazard is an important task for planners, engineers, and scientists. Peak ground acceleration serves as a basic tool for preparation of seismic hazard map in a tectonically active area. Attenuation relations are commonly used for computing peak ground acceleration at any site. Although attenuation relationship provides a good estimate of peak ground acceleration, these relations are mainly controlled by the data used for its derivation. With the advancement of seismology several techniques are used to simulate various strong motion parameters. These techniques are (i) stochastic simulation technique [1], (ii) empirical GreenĄ¯s Function technique (EGF) [2, 3], (iii) composite fault modeling technique [4], and (iv) semi empirical technique [5]. Recently semi empirical technique has been used for simulating earthquake ground motion due to a buried rectangular rupture plane [5¨C13]. One of the advantages of this method is its use of attenuation relation of limited magnitude range for forecasting large earthquake. Seismic hazard in an area can be estimated by either the probabilistic seismic hazard assessment approach (PSHA) or the deterministic seismic hazard assessment approach (DSHA) [14]. Both approaches use the same datasets, which include earthquake sources, occurrence frequencies, and ground motion attenuation
%U http://www.hindawi.com/journals/ijge/2013/825276/