Tsunami detection by GPS-derived ionospheric total electron content.

Area of Science:

• Geophysics
• Atmospheric Physics
• Seismology

Background:

• Earthquakes and tsunamis pose significant natural hazards.
• Ionospheric disturbances can be triggered by seismic and oceanic events.
• Understanding these relationships is crucial for disaster preparedness.

Purpose of the Study:

• To investigate the relationship between tsunamigenic earthquakes and ionospheric total electron content (TEC) changes.
• To analyze TEC variations associated with the 2014 Pisagua and 2015 Illapel earthquakes in Chile.
• To explore the potential of TEC monitoring for earthquake and tsunami early warning systems.

Main Methods:

• Analysis of GPS-derived TEC data from two major Chilean subduction earthquakes.
• Comparison of TEC change patterns with tide-gauge data to understand tsunami propagation.
• Identification and correlation of TEC signals with seismic wave types (Acoustic Rayleigh waves) and atmospheric waves (Acoustic Gravity waves, Internal Gravity waves).

Main Results:

• TEC changes were observed during both the Pisagua and Illapel earthquakes.
• The spatial distribution of TEC changes differed between the two events, correlating with tsunami propagation directions.
• Three distinct TEC signals were identified, linked to Acoustic Rayleigh waves, Acoustic Gravity waves, and Internal Gravity waves.

Conclusions:

• Ionospheric TEC changes serve as reliable indicators of earthquake and tsunami occurrences.
• The observed TEC patterns provide insights into tsunami wave propagation.
• TEC monitoring can be integrated into multi-parameter early warning systems for enhanced disaster detection.