​GU INSTITUTE OF EARTHQUAKE
PREDICTION

Using a consistent spatial window centered on Yellowstone (44.615°N, -110.6°W; radius 80 km), we analyzed the Seismicity Index S time series from 1984-2025 at multiple magnitude thresholds and time scales (annual/monthly/weekly). S exhibits a persistent long-term increase that remains present when smaller earthquakes are excluded (M≥2.0 and M≥2.5). This indicates that the observed intensification is not solely an artifact of small-event catalog completeness. Importantly, the