Earthquakes in Japan — May 2025

47 earthquakes were recorded in Japan during May 2025, an average of 1.5 per day.

47 reached magnitude 4 or above and 7 reached magnitude 5 or above. The average focal depth was 106 km.

The month's largest event in Japan was a magnitude 6.1 earthquake near Kushiro, Japan on 31 May 2025 at 08:37 UTC. A magnitude 6.1 earthquake radiates roughly 21,301 tons of TNT equivalent in seismic energy.

That is close to the Japan monthly average of 57 events over the period we cover, and up from the 42 recorded the previous month.

66% of events here are shallow (under 70 km), 21% intermediate (70–300 km) and 13% 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 40 in the magnitude 4 range, 6 in the magnitude 5 range, 1 in the magnitude 6 range.

Activity peaked on 31 May, when 6 events were recorded.

The month's largest events were M6.1 near Kushiro, Japan on 31 May at 10 km; M5.5 near Bonin Islands, Japan on 13 May at 454 km; M5.4 near Urakawa, Japan on 22 May at 59 km.

That is 17% below the 57 events Japan averages per month across the 21 months on record.