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Explosion Source Analysis and Discrimination From Regional Distance Seismic Observations

Description: 

This study utilizes regional seismic observations to investigate earthquakes and announced explosions in the Democratic People’s Republic of Korea (DPRK). We compute the coda spectral ratios and Relative Source Time Functions (RSTFs) at common stations to isolate source information from additional path and site effects within the measurements. The resulting frequency-dependent amplitude ratios reflect source differences between the two seismic events, which can then be fitted with parametric models that map observations to seismic source parameters. In the case of the RSTFs, the results also provide a time-domain representation of the source-time function. This work allows us to identify spectral differences between explosions and nearby earthquakes. The measurements also agree with estimated earthquake and explosion source models for seismic events occurring at or near the DPRK test site. We analyze parameter trade-offs in these models and quantify the bias associated with source parameter estimation. The coda spectral ratios between explosions and earthquakes reveal that the explosive sources exhibit lower S-wave corner frequencies and S-wave spectral amplitudes (at high frequencies). These results show that a comparing spectra between different source types via spectral ratios provides valuable insights for seismic discrimination and source characterization efforts.

Session: Advancements in Forensic Seismology and Explosion Monitoring [Poster Session]

Type: Poster

Date: 5/2/2024

Presentation Time: 08:00 AM (local time)

Presenting Author: Jonas

Student Presenter: No

Invited Presentation: 

Authors