SLIP BEHAVIOR OF THE 2015 NEPAL MW7.9 EARTHQUAKE CONSTRAINED BY TELESEISMIC, STATIC AND HIGH-RATE GPS DATA

On 25 April 2015, a devastating (Ms 8.1) earthquake struck the central Nepal, Himalaya. We retrieve slip distribution and rupture history of this earthquake and its largest aftershock (Ms7.5) on May 12 through a joint inversion of teleseismic waveform recorded at ～30 GSN stations, 40 static offsets and 7 strong motion waveforms collected by GPS networks in Tibet and Nepal. The slip model shows that the rupture propagated eastwards during the mainshock at ~2.5 km for about 60 seconds and most of seismic energy radiated within the initial 35 seconds. The coseismic slip is characterized largely by two compact patches characterized by pure thrusting motions with an average slip of 2.5 meters over an area of 150 km long by 120 km –wide on the Main Himalayan Thrust fault. The largest aftershock is localized within the smaller patch of the mainshock with the similar characteristics. The total seismic moment of the mainshock and the largest aftershock is estimated to 9.4×10²⁰ Nm , corresponding to Mw 7.9.