Earthquakes in Tonga — January 2025

14 earthquakes were recorded in Tonga during January 2025, an average of 0.5 per day.

14 reached magnitude 4 or above and 5 reached magnitude 5 or above. The average focal depth was 173 km.

The month's largest event in Tonga was a magnitude 5.1 earthquake near Neiafu, Tonga on 28 January 2025 at 21:06 UTC. A magnitude 5.1 earthquake radiates roughly 674 tons of TNT equivalent in seismic energy.

That is close to the Tonga monthly average of 18 events over the period we cover, and up from the 13 recorded the previous month.

50% of events here are shallow (under 70 km), 21% intermediate (70–300 km) and 29% 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 9 in the magnitude 4 range, 5 in the magnitude 5 range.

Activity peaked on 05 January, when 3 events were recorded.

The month's largest events were M5.1 near Neiafu, Tonga on 28 January at 78 km; M5.1 near Pangai, Tonga on 10 January at 10 km; M5.1 near ‘Ohonua, Tonga on 02 January at 10 km.

That is 24% below the 18 events Tonga averages per month across the 21 months on record.