The island group is situated at the subduction zone of the Australian and the Pacific tectonic plates and within the Ring of Fire where intense seismic activities occur.
It is about 200km to the west of the Tonga Trench which is a potential source of tsunami. Most of its atoll islands including the main island are very flat with average altitude of 2–5 meters hence highly vulnerable to tsunami inundation. Volcanic and tsunami hazards are often triggered by earthquake events.
The blow table provides a summary of all incidences of earthquakes and their impacts on Tonga.