Earthquakes in Tonga — December 2024

13 earthquakes were recorded in Tonga during December 2024, an average of 0.4 per day.

13 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 5.9 earthquake near Neiafu, Tonga on 15 December 2024 at 15:03 UTC. A magnitude 5.9 earthquake radiates roughly 10,676 tons of TNT equivalent in seismic energy.

That is below the Tonga monthly average of 18 events over the period we cover — a comparatively quiet month, and down from the 15 recorded the previous month.

46% of events here are shallow (under 70 km), 31% intermediate (70–300 km) and 23% 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 8 in the magnitude 4 range, 5 in the magnitude 5 range.

Activity peaked on 04 December, when 2 events were recorded.

The month's largest events were M5.9 near Neiafu, Tonga on 15 December at 213 km; M5.5 near Houma, Tonga on 28 December at 551 km; M5.4 near ‘Ohonua, Tonga on 07 December at 10 km.

That is 30% below the 18 events Tonga averages per month across the 21 months on record.