Tuvalu name Ellice was applied to all nine islands after the work of English hydrographer Alexander George Findlay. The Ellice Islands came into Great Britain's sphere of influence in the late 19th century, as the result of a treaty between Great Britain and Germany relating to the demarcation of the spheres of influence in the Pacific Ocean. Each of the Ellice Islands was declared a British Protectorate by Captain Gibson of between 9 and 16 October 1892. The Ellice Islands were administered as a British protectorate by a Resident Commissioner from 1892 to 1916, as part of the British Western Pacific
Geology of the Pacific Ocean . The Pacific Ocean developed from the Panthalassa, a vast global ocean, following the breakup of the supercontinent Pangaea in the Mesozoic Era, gradually forming Gondwana and Laurasia, which in turn divided. There is no firm date for when the changeover occurred, as the replacement of the sea bed is a continuous process, though reconstruction maps often change the name from Panthalassic to Pacific around the time the Atlantic Ocean began to open. The Panthalassic Ocean first opened around 750 million years ago at the breakup of Rodinia, but the oldest Pacific Ocean floor is only around 180 Ma old.