Ionospheric Plasma Response to Mw 8.3 Chile Illapel Earthquake on September 16, 2015

Abstract

The lithosphere and the atmosphere/ionosphere continuously exchange energy through various coupling mechanisms. In particular, the earth surface displacement caused by earthquakes, volcanoes and tsunamis can manifest as ionospheric plasma perturbations. We investigate the coseismic induced ionospheric total electron content (TEC) perturbations following the Mw 8.3 Illapel thrust earthquake that occurred on September 16, 2015. The continuous global positioning system (GPS) data at 48 sites from Centro Sismolo´gico Nacional and International GNSS Service GPS networks have been used in this study. The nearest GPS site recorded the ionospheric response 10 min after the occurrence of this earthquake. The maximum vertical coseismic induced TEC amplitude is *1.4 TECU, and the perturbations are pronounced in the northern region of the epicenter and confined to less than *1500 km radius. The average horizontal acoustic wave velocity has been determined as *1260 m/s. We also observed acoustic resonance recorded by PRN 12 at 4.3 mHz corresponding to the first overtone of acoustic mode and lasting for about 30 min. In this study, we present characteristics of GPS derived ionospheric plasma perturbations following Illapel earthquake.