Multi-precursory Analysis of Phalla Earthquake (July 2015; Mw 5.1) Near Islamabad, Pakistan

The recent scientific progress in understanding the hierarchical nature of the lithosphere and its dynamics based on systematic earthquake monitoring helps in designing an improved earthquake forecasting strategy. This study presents a detailed multi-precursory analysis of a shallow, moderate Phalla earthquake (July 24, 2015; Mw 5.1; Depth = 10 km) near Islamabad, Pakistan, 24 km away from the monitoring site within the context of earthquake forecasting. The instrumental setup (soil radon monitor and space–ground-based ionosonde) for precursory monitoring of earthquake activity is installed at the foothills of Margalla along the Main Boundary Thrust. For identification of abnormal behavior of ionospheric parameters and soil radon flux, a statistical criterion consistent with other studies is used. Our analyses reveal the effect of pre- and co-seismic changes in the form of anomalous behavior of local ionospheric perturbations (2–15 days prior), soil radon flux (3 days prior), and seismic quiescence related to Phalla earthquake. The solar/geomagnetic conditions and meteorological parameters remained normal during the anomalous periods. Moreover, multi-precursory approach adopted in this study for earthquake prediction/forecasting can serve as a potential indicator of seismic activity.