Wavelet-Based P-Wave Detection in High-Rate GNSS Data: A Novel Approach for Rapid Earthquake Monitoring in...

Area of Science:

• Geophysics
• Seismology
• Geodesy

Background:

• Traditional seismic methods struggle with noisy environments for earthquake detection.
• High-rate Global Navigation Satellite System (GNSS) data offers potential for rapid P-wave detection.
• Effective earthquake monitoring and tsunami early warning systems require accurate and timely P-wave identification.

Purpose of the Study:

• To apply a wavelet-based method for analyzing GNSS displacement waveforms.
• To accurately detect P-waves from major Indonesian earthquakes using GNSS data.
• To evaluate the effectiveness of GNSS data as a complement to seismic networks.

Main Methods:

• Wavelet-based analysis using a Mexican hat wavelet and dynamic threshold.
• Analysis of three-component displacement waveforms from GNSS data.
• Comparison with seismic records from the Indonesian geophysical agency.

Main Results:

• Reliable detection of horizontal P-wave components with a time delay under 90 seconds.
• Inconsistent detection of vertical P-wave components due to noise.
• Identification of P-wave energy in the 0.02-0.5 Hz pseudo-frequency range.
• Demonstrated sensitivity to low-frequency signals.

Conclusions:

• GNSS data, analyzed with a wavelet method, can effectively complement seismic networks for earthquake characterization.
• The approach is sensitive to low-frequency P-wave signals relevant for earthquake monitoring.
• Improving vertical component noise suppression is crucial for real-time early warning system applications.