Kiribati ([kɪribas] KIRR-i-bas or ˌkɪrəˈbɑdi; Gilbertese: [ˈkiɾibas]), officially the Independent and Sovereign Republic of Kiribati, is an island nation in the central tropical Pacific Ocean. The permanent population is just over 100,000 (2011) on 800 square kilometres (310 sq mi). The nation is composed of 32 atolls and one raised coral island, Banaba, dispersed over 3.5 million square kilometres, (1,351,000 square miles) straddling the equator, and bordering the International Date Line at its easternmost point.The name Kiribati is the local pronunciation of Gilberts, which derives from the main island chain, named the Gilbert Islands after the British explorer Thomas Gilbert, who sailed through the islands in 1788.The capital, South Tarawa, consists of a number of islets connected through a series of causeways, located in the Tarawa archipelago. Kiribati became independent from the United Kingdom in 1979. It is a member of the Commonwealth of Nations, the IMF and the World Bank, and became a full member of the United Nations in 1999.