Earthquakes in Japan — December 2024

43 earthquakes were recorded in Japan during December 2024, an average of 1.4 per day.

41 reached magnitude 4 or above and 5 reached magnitude 5 or above. The average focal depth was 93 km.

The month's largest event in Japan was a magnitude 5.7 earthquake near Izu Islands, Japan on 26 December 2024 at 21:02 UTC. A magnitude 5.7 earthquake radiates roughly 5,351 tons of TNT equivalent in seismic energy.

That is close to the Japan monthly average of 56 events over the period we cover, and level with the 43 recorded the previous month.

58% of events here are shallow (under 70 km), 30% intermediate (70–300 km) and 12% deep-focus (over 300 km). That proportion of deep-focus events is the signature of a subduction zone: only a cold slab descending into the mantle stays brittle enough to rupture at those depths.

By band, the catalogue holds 2 in the magnitude 3 range, 36 in the magnitude 4 range, 5 in the magnitude 5 range.

Activity peaked on 04 December, when 4 events were recorded.

The month's largest events were M5.7 near Izu Islands, Japan on 26 December at 10 km; M5.3 near Tomioka, Japan on 27 December at 58 km; M5.2 near Makurazaki, Japan on 17 December at 165 km.

That is 23% below the 56 events Japan averages per month across the 22 months on record.