TITLE:
South Atlantic Anomaly, Ionospheric Signals from Seismic Events
AUTHORS:
Marilia Hagen, Anibal Azevedo
KEYWORDS:
South Atlantic Anomaly, Ionosphere Signs, Earthquake Prediction
JOURNAL NAME:
Natural Science,
Vol.12 No.3,
March
18,
2020
ABSTRACT: The
purpose of this paper is to analyze the most significant events that occurred
in the period 1996-2018 located under the South Atlantic Anomaly (SAA), where
the earth’s magnetic field is weaker and the trapped particles during the
geomagnetic storms suffer decay over time. The time examined corresponds to the
Solar Cycles 23 and 24; the area covered is defined by the following
coordinates: 0N,-50S, 40E,-90W. Some significant events in this region
reported Very Low Frequency (VLF) and Ultra Low Frequency (ULF) waves before
the event, varying from minutes, hours, and even weeks before the earthquakes. Our
study searches for a mechanism to explain why the crust creates electromagnetic
signs detected at the ionosphere. Piezoelectric currents flow on the crust,
combining with the magnetic field lines, temporarily producing pre-seismic
electromagnetic pulses that are detected at the ionosphere prior to the events.
The mechanism that allows electromagnetic signs to be detected at the ionosphere is also elucidated.
These signs are brief, and they will cease with the beginning of the shock or
shortly thereafter. However, some features contribute to making the signs
impossible to detect, involving crust materials, location, magnitude, and
depths. We suggest that these ionospheric events could happen for other kinds
of hazard events, such as Volcanos.