Located in Oceania, Tonga is a small archipelago in the South Pacific Ocean, directly south of Samoa and about two-thirds of the way from Hawaii to New Zealand. It has 169 islands, 36 of them inhabited, are divided into three main groups – Vava'u, Ha'apai, and Tongatapu – and cover an -long north–south line. The total size is just. Due to the spread out islands it has the 40th largest Exclusive Economic Zone of. The largest island, Tongatapu, on which the capital city ofNukualofa is located, covers. Geologically the Tongan islands are of two types: most have a limestone base formed from uplifted coral formations; others consist of limestone overlaying a volcanic base.
Climate
The climate is tropical with a distinct warm period, during which the temperatures rise above, and a cooler period, with temperatures rarely rising above. The temperature increases from, and the annual rainfall is from as one moves from Tongatapu in the south to the more northerly islands closer to the Equator. The average wettest period is around March with on average. The average daily humidity is 80%. Cyclones can occur from October to April.
Geology
Though administratively divided into the three main island groups of Tongatapu, Ha'apai, and Vava'u, the Tonga archipelago is actually made of two geologically different parallel chains of islands. The western islands, such as ʻAta, Fonuafo'ou, Tofua, Kao, Lata'iki, Late, Fonualei, Toku, Niuatoputapu, and Tafahi, make up the Tongan Volcanic Arc and are all of volcanic origin. They were created from the subduction of the western-moving Pacific plate under the Australia-India plate at the Tonga Trench. The Tongan Islands sit on the Australia-India plate just west of the Tonga Trench. These volcanoes are formed when materials in the descending Pacific plate heat and rise to the surface. There is only limited coral reef development on these islands, except for Niuatoputapu. The eastern islands are not volcanic and sit above the mostly submerged Tonga ridge that runs parallel to the Tongan Volcanic Arch and the Tongan Trench. Of these islands, only 'Eua has risen high enough to expose its underlying Eocene volcanic bedrock, the rest are either low coral limestone islands or sand cay islands. These islands are surrounded by "a protective and resource-rich labyrinth of fringing, apron and off-shore barrier reefs" that have supported most of the human settlement in Tonga ever since the first Lapita People arrived circa 900 BCE. The Tongan Volcanic Arc has been important in supplying the islands on the Tonga ridge with an andesitetephra soil that has resulted in "an extremely rich soil capable of supporting a high-yield, short-fallow agricultural system." Also, the andesite/basalt from the volcanoes were initially used as "hammerstones, weaving weights, cooking stones, and decorative pebbles for grave decoration." Tafahi island in the far north provided volcanic glass to initial human settlers. In December 2014 and January 2015, a volcanic island1 km wide by 2 km long was created adjacent to the island of Hunga Ha'apai 65 kilometers northwest of Nuku'alofa. The volcanic eruption has built the new island to a height of 100 m composed of ash and large rock fragments. In regards to volcanism, Tonga has moderate volcanic activity. Fonualei has shown frequent activity in recent years, while Niuafo'ou, which last erupted in 1985, has forced evacuations; other historically active volcanoes include Late and Tofua. Natural hazards include earthquakes and volcanic activity at Fonuafo'ou and Late'iki.
Facts
Geographic coordinates: Area:
total:
land:
water: Coastline: Maritime claims:
continental shelf: depth or to the depth of exploitation
