Decoding Intrinsic and Scattering Seismic Attenuation at the Conjunction of the Cocos, Nazca, Caribbean, and Panama Plates

ABSTRACT Panama is located in a unique tectonic setting, the Panama triple junction, where the result of the interaction of the Cocos, Nazca, and Caribbean plates takes place. This interaction is characterized by high seismicity; therefore, seismic risk analysis is essential to understand the possible consequences derived from these earthquakes. Despite historical records of large-magnitude earthquakes and significant seismic hazard, seismic attenuation studies in this area have been largely absent. In this study, we applied the multiple lapse time window analysis method to quantify seismic attenuation parameters for the entirety of Panama. This approach allowed us to separately estimate intrinsic attenuation (Qi) and scattering attenuation (Qs), providing insights into energy dissipation mechanisms. We considered 288 local earthquakes with magnitudes between 2.5 and 4.5 and recorded from January 2014 to December 2019. Our results show that scattering attenuation dominates at low frequencies (1–2 Hz), whereas both attenuation mechanisms are comparable at higher frequencies. Spatially, seismicity and attenuation values are highest along the edges of the Panama microplate, decreasing toward the central region. These findings highlight the importance of incorporating regional attenuation models into ground-motion prediction equations to improve seismic hazard maps and strengthen earthquake-resistant infrastructure in Panama. This study represents the first comprehensive assessment of seismic attenuation for Panama and provides a framework for future regional seismic hazard analyses.