Multifractal analysis for seismic wave in Kathmandu valley after Gorkha Earthquake-2015, Nepal

Abstract

We applied the multiscale signal processing technique, the Wavelet Transform Modulus Maxima (WTMM) to characterize high frequency properties of strong motion waveforms, in particular the temporal distribution and strength of singularities in Gorkha earthquake, 25th April 2015. We first explored their relation to earthquake data source. Then we applied the WTMM analysis to strong motion recordings. These showed that the timing and exponent of singularities measured by the WTMM method on the ground motion wave field are directly related to the position and exponent of assumed initial stress singularities on the fault plane. We found strong motion recordings at near the epicenter site have very high multifractality than far sites. Some differences and similarities among sites were successfully detected.

Seismic phases of 25 April 2015 (Mw 7.8) Earthquake and 12 May 2015 (Mw 7.3) Earthquake Predicted by AK135 Model - A comparison

“…Similarly, from the multifractal study of seismic signal of Gorkha earthquake, smoother seismic signal was noticed with growing distances and the time duration of main event was noticed to be very short [9]. A group of researchers [10] studied the finite rupture processes and the associated 3D ground motion of the Gorkha earthquake and Dolakha earthquake and concluded that the different rupture features between these events could be related to difference in fault zone structure.…”