Gilbert and Ellice Islands the latitude of 5° to 10° south and longitude of 176° to 180°, west of the International Date Line. The Ellice Islands are midway between Hawaii and Australia. The Ellice Islands are recognised as part of the Polynesia subregion of Oceania. In 1606 Pedro Fernandes de Queirós sighted Butaritari and Makin, which he named the Buen Viaje (‘good trip’ in Spanish) Islands. The Gilbert Islands were named in 1820 by a Russian Admiral, Baron Johann von Krusenstern, after a British captain, Thomas Gilbert, who encountered the archipelago in 1788 while exploring an Outer Passage route from Port Jackson to Canton.
Geology of the Pacific Ocean Plate in the north, the Cocos Plate off today's Central America, and the Nazca and Phoenix Plates in the southern Pacific. Charles Darwin had proposed a theory of the slow subsidence of the ocean floor based on his studies of Pacific oceanic islands, seamounts (underwater volcanoes) and guyots (flat-topped seamounts). His observations have been verified and expanded in the development of plate tectonic theory. The tectonic plates continue to move today. The slowest ridge spreading rate is across the Gakkel Ridge in the Arctic Ocean which separates at less than 2.5 cm/yr while the fastest, across the East Pacific Rise