Scale invariance behavior for pre and post-2015 Nepal Gorkha earthquake GPS time series based on fractal analysis

Abstract

The continuous nature of GPS time series is complex. Fractal analysis can give a better understanding of the complex nature of the GPS time series. Here we have considered the North and East components GPS position time series of the Patna and Ranchi station network (in which Patna site has suffered a coseismic displacement of 7±3 mm due to the 25th April 2015 Gorkha Earthquake). We found variation in scaling exponent β, before and after April 2015, Gorkha, Nepal Earthquake. The study region consists of the Bihar-Jharkhand area, where we have taken two of the four permanent sites of the GPS network to compare the results of variation in scaling exponents for the three sites. The variation in exponents (β) value is dependant on the distribution of tectonic elements at the two sites. The three sites show lower values of exponents (β) before the earthquake than after the earthquake signifying high seismic energy and convergence due to strain accumulation compared to after the main event. A combined study of GPS and Scaling exponents will represent the hazardous zone in India's South Himalayan region.