Scaling relations of moment magnitude, local magnitude, and duration magnitude for earthquakes originated in northeast India

Abstract

In this study, we aim to improve the scaling between the moment magnitude (MW), local magnitude (ML), and the duration magnitude (MD) for 162 earthquakes in Shillong-Mikir plateau and its adjoining region of northeast India by extending the MW estimates to lower magnitude earthquakes using spectral analysis of P-waves from vertical component seismograms. The MW-ML and MW-MD relationships are determined by linear regression analysis. It is found that, MW values can be considered consistent with ML and MD, within 0.1 and 0.2 magnitude units respectively, in 90 % of the cases. The scaling relationships investigated comply well with similar relationships in other regions in the world and in other seismogenic areas in the northeast India region.