Source parameters and f _max in lower Siang region of Arunachal lesser Himalaya

A data set of 60 local events (1.9 ≤ M_w ≤ 3.6) collected by a temporary digital network deployed in the Siang region of Arunachal Lesser Himalaya during July 2011 to Feburary 2012 is analysed to study the source parameters and f_max. The software EQK_SRC_PARA (Kumar et al. in Int J Geosci 3(5):1142–1149, 2012) that considers Brune’s model with a high-frequency diminution factor (Boore in Bull Seismol Soc Am 73:1865–1894, 1983) has been used to estimate the spectral parameters namely: low-frequency displacement spectral level (Ω₀), corner frequency (f_c) and f_max. These obtained spectral parameters are used to estimate source parameters, namely: seismic moment, source dimension and stress drop and to study the characteristics of f_max in this region. Seismic moment varies from 6.13 × 10¹⁸ dyn-cm to 3.15 × 10²¹ dyn-cm; the source radii vary from about 175 to 357 m. The stress drops of these events vary from 0.2 to 56 bars and shows general increasing trend with increase in seismic moment. Various plots of both f_c and f_max with seismic moment, focal depth, epicentral distance and site showed the same amount of scatters and trends. From this study, it is found that f_max has similar behavior as f_c to seismic moment showing that it is also due to source process, and the same amount of scatter in both cut-off frequencies may be due to either source complexities or site effects or both. Both f_c and f_max seems independent of epicentral distance and focal depth. Relationships between f_max and seismic moment and stress drop are obtained.