Abstract:
. Infrasound generated during a seismic event upon
reaching the ionospheric heights possesses the ability to perturb
the ionosphere. Detailed modelling investigation considering
1-D dissipative linear dynamics, however, indicates that
the magnitude of ionospheric perturbation strongly depends
on the magnetic field inclination. Physics-based SAMI2
model codes have been utilized to simulate the ionosphere
perturbations that are generated due to the action of the vertical
wind perturbations associated with the seismic infrasound.
The propagation of the seismic energy and the vertical
wind perturbations associated with the infrasound in the
model has been considered to be symmetric about the epicentre
in the north–south directions. Ionospheric response to
the infrasound wind, however, has been highly asymmetric
in the model simulation in the north–south directions. This
strong asymmetry is related to the variation in the inclination
of the Earth’s magnetic field north and south of the epicentre.
Ionospheric monitoring generally provides an efficient tool to
infer the crustal propagation of the seismic energy. However,
the results presented in this paper indicate that the mapping
between the crustal process and the ionospheric response is
not a linear one. These results also imply that the lithospheric
behaviour during a seismic event over a wide zone in low
latitudes can be estimated through ionospheric imaging only
after factoring in the magnetic field geometry.
