Efficiency of coseismic ionospheric perturbations in identifying crustal deformation pattern: Case study based on Mw 7.3 May Nepal 2015 earthquake

Abstract

The amplitude asymmetry and initial polarity of seismic induced ionospheric perturbations around the epicenter are considered to be important in providing information about the rupture propagation and related vertical surface deformation. To comprehend this, we study ionospheric perturbations related to the 12 May 2015, Mw 7.3 Nepal earthquake. We model the coseismic slip associated with the event using the interferometric synthetic aperture radar derived surface deformation data. The ionospheric perturbations associated with the obtained surface deformation are explained in terms of rupture propagation, favorable geomagnetic field-wave coupling, and satellite geometry effects. We discuss the effects of phase cancelation on the perturbation evolution for various receiver satellite line-of-sight configurations invoking an elementary version of satellite geometry factor. The present study thus elucidates further the role of nontectonic forcing mechanisms while identifying ground source pattern using the associated ionospheric perturbations.