 Nui was struck by a giant wave on 16 February 1882; earthquakes and volcanic eruptions occurring in the basin of the Pacific Ocean – the Pacific Ring of Fire – are possible causes of a tsunami.Tuvalu experienced an average of three tropical cyclones per decade between the 1940s and 1970s, however eight occurred in the 1980s.The impact of individual cyclones is subject to variables including the force of the winds and also whether a cyclone coincides with high tides.