List of earthquakes in Fiji
This is a list of earthquakes in Fiji which caused damage, casualties and/or a tsunami. As indicated below, magnitude is measured on the moment magnitude scale or the surface wave magnitude scale for older earthquakes. The present list is not exhaustive, and furthermore reliable and precise magnitude data is scarce for earthquakes that occurred before the development of modern measuring instruments.
Background
Fiji lies in a complex tectonic setting along the boundary between the Australian plate and the Pacific plate. Southwards from Fiji, the Pacific plate is subducting beneath the Australian plate along the Tonga Trench forming the Tonga Ridge island arc system and the Lau Basin back-arc basin. To the southwest of Fiji the Australian plate is subducting beneath the Pacific plate forming the Vanuatu Ridge island arc system and the North Fiji back-arc basin. Hence, the region has undergone a complex process of plate convergence, subduction, and arc volcanism from the Middle Eocene to the Early Pliocene. Many of the larger islands, such as Viti Levu, are of volcanic origin. Volcanism still exists, and there are Holocene volcanoes in Fiji. The Fiji Platform lies in a zone bordered with active extension fault lines around which most of the shallow earthquakes were centered. These fault lines are the Fiji fracture zone to the north, the 176° Extension Zone to the west, and the Hunter fracture zone to the east.The area between Fiji and New Zealand lies within arguably the most active deep-focus faulting zone on the planet, caused by the Pacific Plate subducting under the Australian Plate, Tonga Plate, and Kermadec Plate. This specific region experiences extremely frequent seismic activity, with earthquakes exceeding 4.0 occurring almost daily. Earthquakes as large as Mw 8.2 are known to occur in this faulting zone. As a result, almost all of Fiji's earthquakes occur at depths exceeding, and of the 210 ≥ 6.0 earthquakes that have been recorded near Fiji, only 66 struck less than beneath the surface, and only 15 are thought to have caused particularly strong shaking, according to the United States Geological Survey.