Earthquakes in the United States — December 2024

9020 earthquakes were recorded in the United States during December 2024, an average of 291.0 per day.

83 reached magnitude 4 or above and 26 reached magnitude 5 or above. The average focal depth was 13 km.

The month's largest event in the United States was a magnitude 7.0 earthquake near 2024 Offshore Cape Mendocino, United States on 05 December 2024 at 18:44 UTC. A magnitude 7.0 earthquake radiates roughly 476,879 tons of TNT equivalent in seismic energy.

That is well above the the United States monthly average of 7104 events over the period we cover — an unusually active month, and up from the 3420 recorded the previous month.

96% of events here are shallow (under 70 km), 4% intermediate (70–300 km) and 0% deep-focus (over 300 km). Almost everything here is crustal. That is characteristic of transform faulting or continental deformation rather than subduction — and it means shaking at the surface is strong for the magnitudes involved.

By band, the catalogue holds 9 in the magnitude -2 range, 660 in the magnitude -1 range, 2121 in the magnitude 0 range, 4128 in the magnitude 1 range, 1682 in the magnitude 2 range, 337 in the magnitude 3 range.

Activity peaked on 09 December, when 545 events were recorded.

16 event(s) this month carry a USGS link to NOAA tsunami information; the flag does not indicate whether a tsunami occurred.

The month's largest events were M7.0 near 2024 Offshore Cape Mendocino, United States on 05 December at 10 km; M6.3 near Adak, United States on 08 December at 18 km; M6.3 near Adak, United States on 09 December at 19 km.

That is 27% above the 7104 events the United States averages per month across the 22 months on record.