Magnitude (M)
Modern USGS feeds typically report moment magnitude (often labeled simply as mag). It is roughly logarithmic: each whole-number step is about 32× more energy. Our map colors and marker sizes scale with magnitude so large events stand out.
Intensity
Intensity (e.g. Modified Mercalli) is what people and buildings experience at a location. A moderate quake nearby can feel stronger than a larger, deeper, or more distant one. Felt reports on USGS event pages reflect intensity, not magnitude.
Depth
Shallow events (often <70 km) tend to shake harder at the surface for the same magnitude. Intermediate and deep events still matter for science and sometimes for distant effects, but local intensity patterns differ.
Amplitude and energy
USGS says each whole-number increase in magnitude is a tenfold increase in measured amplitude and about 32 times more energy. The magnitude energy comparison applies that rule to two numbers. It does not say where or when an earthquake will happen.
Ring of Fire yearly snapshot (from SUMMARY)
In the catalog window 2025-09-13 → 2026-09-12 UTC: 16,268 M≥4 events; 80.6% inside our RoF corridors; strongest M7.8. Those are historical counts — not a forecast for the next year.