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.
