Geology of the Pacific Ocean Geology of the Pacific Ocean The Pacific Ocean evolved in the Mesozoic from the Panthalassic Ocean, which had formed when Rodinia rifted apart around 750 Ma. The first ocean floor which is part of the current Pacific Plate began 160 Ma to the west of the central Pacific and subsequently developed into the largest oceanic plate on Earth. The tectonic plates continue to move today. The slowest spreading ridge is the Gakkel Ridge on the Arctic Ocean floor, which spreads at less than , while the fastest, the East Pacific Rise near Easter Island, has a spreading rate of over
Fridtjof Nansen carried out researches in the northern Atlantic, and in 1912 he took his own yacht, "Veslemøy", to Bear Island and Spitsbergen. The main objective of the "Veslemøy" cruise was the investigation of salinity in the North Polar Basin. One of Nansen's lasting contributions to oceanography was his work designing instruments and equipment; the "Nansen bottle" for taking deep water samples remained in use into the 21st century, in a version updated by Shale Niskin. At the request of the Royal Geographical Society, Nansen began work on a study of Arctic discoveries, which developed into a two-volume history of the exploration