Spectral Analysis and Waveform Modelling of Jangalwar Earthquake (Mw 4.1), Chenab Valley, Jammu

Abstract

An earthquake of M w 4.1 occurred in the Jangalwar area of Chenab valley of Jammu and Kashmir on 29 th May, 2017. This earthquake occurred within the source zone of the Jangalwar earthquake of 2013 (M w 5.7) which was followed by aftershocks for about two months. The current paper presents results on spectral analysis and waveform modelling of this earthquake. Its epicenter was located at 33.110 o N, 75.896 o E between the Panjal Thrust and Kishtwar Window. From the travel time and waveform inversion, focal depth of the event was located at 11 km. The estimated seismic moment was calculated at 15.4 dyne-cm, source radius of 0.585 km, moment magnitude 4.1, corner frequency of 2.39 Hz and stress drop of 50.6 bars. The focal plane solution of the event indicates thrust movement with the fault plane strike of 323 o , dip 39 o and rake 100 o . The source fault of the event appears synthetic to NW-SE striking Panjal Thrust. This current activity may be related to reactivation of ramp emanating from the decollement or emergence of a new splay from the Panjal Thrust.