Only two out of 33 earthquakes that occurred in Tonga during the month of August were felt, according to the new Tonga Geological Services Seismic Bulletin of 4 September.

The seismic events were felt mainly on Tongatapu and ‘Eua, and people in two storey buildings or higher would have felt a slightly greater shake than those in a single storey building. 

None of the 33 earthquakes were significant enough to produce major damage or generate tsunami waves.

The two felt earthquakes measured 5.0 and 5.2 magnitude, while the rest had magnitudes greater than or equal to 4.5.

The first felt earthquake (5.0 magnitude) occurred at a depth of 10km and 357km south-south west of Nuku’alofa on 15 August. While the second felt earthquake (5.2 magnitude) occurred on 25 August, at a depth of 20.78km, 79km south-south west of Nuku’alofa.

All 33 earthquakes occurred at random locations throughout Tongan waters measuring 4.5 to 5.6 magnitudes.

Twenty-three (23) of the earthquakes occurred in shallow water with an average magnitude of 4.8. While six earthquakes occurred in intermediate waters and four earthquakes occurred in deeper waters.

The earthquakes were directly related to the subduction zone, which is a region of the Earth’s crust where tectonic plates overlap.

Tonga is located within the Pacific Ring of Fire zone where there are active volcanoes and frequent earthquakes.