Quantifying Regional Body Wave Attenuation in a Seismic Prone Zone of Northeast India

摘要

We evaluated the body wave attenuation parameter in Kopili region of northeast India. Using the modified algorithm of coda normalization method, we delineated frequency-dependent attenuation for both P and S waves. Taking more than 300 seismograms as input, we comprehensively studied microearthquake spectra in the frequency range of 1.5-12 Hz. The estimated values of and show strong frequency dependence. Based on this, we formulated empirical relationships corresponding to and for the study region. The relationships emerge to be and , respectively. The ratio is found to be larger than unity for the entire frequency band which implies profound seismic activity and macroscale heterogeneity prevailing in the region. The study may act as the building block towards determination of source parameter and hazard-related studies in the region.