How long does it take to form an island? The geology of the British Isles shows that rocks of the Outer Hebrides have been around for 2.7 billion years. Whereas much of Great Britain is much younger than this; the last major landscape shaping event (before people anyway) was the Last Glacial Maximum at around 18 000 years ago. So to summarise our little corner of the Earth has been a long time in the making. Compare this to the latest addition to Tonga, which started forming in January 2015 and is now around 250m above sea level. The new volcanic island owes its formation to the continuing destruction of the Pacific tectonic plate. Below the sea-floor near Tonga, the Pacific tectonic plate is being pushed under the Australian, Tonga and Niuafo'ou tectonic Plates at a rate of 5-7cm per year. As the Pacific tectonic plate is subducted below these tectonic plates, friction, heat and water cause partial melting of the rocks - generating magma. This in turn leads to volcanism and the formation of volcanic islands. The photos of the new island look superb and as always, great geology makes a great vacation spot!
A newly-formed volcanic island off Tonga could be the country's latest tourism attraction, a local tourism operator says.