The High Frequency Decay Parameter κ (Kappa) in the Region of North East India

Abstract

The high frequency decay parameter k has been considered as one of the important parameters required in the simulation of earthquake strong ground motions necessary for the proper evaluation of seismic hazard of a region. The present study estimated “k” for the highly seismic active region of North East India. The spectral analysis of 598 accelerograms of 32 earthquakes has been done using [1] approach for this purpose. The average values of “k” have been found to be 0.049, 0.047 and 0.040 for L-, T- and V-component respectively. The distance dependence of k is not significant in the region. The k0 (k at R = 0) for soft rock stations is found to be more than those of hard rock sites in consistent with other similar studies. The correlation between “k” and earthquake magnitude at most of the stations for the region under study is not significant which indicates that k depends on the site conditions in the region. The k values estimated in the present study are useful for the evaluation of seismic hazard of the region.