Seismic Hazard of Garhwal Region, Himalaya

Autor: F. F. Aptikaev, Surendra Nadh Somala, Sarit Chanda, O. O. Erteleva, E. A. Rogozhin
Rok vydání: 2020
Předmět:
Zdroj: Izvestiya, Atmospheric and Oceanic Physics. 56:1315-1325
ISSN: 1555-628X
0001-4338
DOI: 10.1134/s0001433820110079
Popis: The region of Garhwal is one of the most seismically active areas in India. Many destructive earthquakes have occurred there in the past. The current seismic activity in Garhwal is also high. The region is characterized by a high population density; therefore, in choosing ways to develop it, protecting the population and reducing material damage from expected strong seismic events are of utmost urgency. The solution primarily requires using various antiseismic measures during construction, which are selected based on the characteristics of seismic treatments. The purpose of this research is to assess the seismic hazard and seismic treatments in some settlements of Garhwal. To solve this problem, data obtained in previous stages of studies in Western Himalaya are interpreted once again. In particular, the results of geological and geophysical and structural and geological studies have made it possible to reveal the main seismogenerating structures and determine their characteristics. The analysis of the data on strong ground motions in the epicenter areas of the Dharamsala (April 26, 1986, Mw = 5.5), Uttarkashi (October 20, 1991, Mw = 6.8), and Chamoli (March 28, 1999, Mw = 6.5) earthquakes and the study of the attenuation patterns of ground accelerations in the Garhwal region have enabled us to estimate the expected maximum magnitudes, focal depths, and source mechanisms of the earthquakes. A regional model of seismic source zones (SSZs) is proposed. Using the results of seismological and seismotectonic studies, the parameters of ground motions during the maximum credible earthquakes are estimated, such as peak ground accelerations, spectra and durations of vibrations, and the seismic-effect value in the seismic intensity scale points for some settlements in Garhwal.
Databáze: OpenAIRE