US States with Most Earthquakes and Magnitudes (2005–Present)

Findings

Alaska records more earthquakes than the rest of the country combined

Across the USGS catalog of magnitude-4.0-and-above earthquakes in US states and territories, Alaska accounts for 8,804 of the 16,995 recorded events, more than half the national total.USGS ComCat, US earthquake data Alaska sits on the Pacific subduction zone, where the Pacific plate dives beneath North America, producing frequent and sometimes very large quakes. Its strongest catalogued event reached magnitude 7.9, and 110 of its earthquakes were significant (magnitude 6 or greater). No other state comes close in raw count.

The next-most-seismic places are Pacific territories, not the lower 48

After Alaska, the highest counts belong to two US Pacific territories astride the same trench system: the Northern Mariana Islands (3,295 earthquakes, peak magnitude 7.7) and Guam (2,421, peak 6.8).USGS ComCat, US earthquake data California, despite its reputation, ranks fourth with 863 events (peak 7.2), followed by Puerto Rico (293), Oregon (260), the US Virgin Islands (212), and Hawaii (198). California's count is lower than many people expect because this catalog counts only magnitude-4.0-and-above events; the state's seismic risk comes less from sheer frequency than from large faults running near dense population centers.

Significant quakes are rare and concentrated

Only 158 of the 16,995 catalogued earthquakes were significant (magnitude 6 or larger), and they cluster where the largest faults are.USGS ComCat, US earthquake data Alaska alone accounts for 110 of them, with the Northern Mariana Islands next at 19; most states recorded a handful or none. Puerto Rico logged 3 significant events (top magnitude 6.4), Hawaii 4 (6.9), and California 8 (7.2). A high total count does not always mean many large quakes: most catalogued events sit near the magnitude-4-to-5 detection floor, so the significant share stays small even in the most active places.

How to read these numbers

These figures come from the USGS Comprehensive Catalog (ComCat), counting earthquakes of magnitude 4.0 and above located within US states and territories.USGS ComCat, US earthquake data Because the catalog counts only magnitude-4.0-and-above events, the many smaller tremors that instruments record are not included, and "significant" here means magnitude 6 or greater. Earthquake catalogs also grow more complete over time as monitoring networks expand, so older periods are less fully captured than recent ones. The data describes recorded seismicity, not forward-looking hazard, which also depends on fault proximity, soil, and building stock. It is not a safety assessment for any specific location.