Oceanic basin an active - and growing - oceanic basin include an elevated mid-ocean ridge, flanking abyssal hills leading down to abyssal plains. The elements of an active oceanic basin often include the oceanic trench associated with a subduction zone. The Atlantic ocean and the Arctic ocean are good examples of active, growing oceanic basins, whereas the Mediterranean Sea is shrinking. The Pacific Ocean is also an active, shrinking oceanic basin, even though it has both spreading ridge and oceanic trenches. Perhaps the best example of an inactive oceanic basin is the Gulf of Mexico, which formed in Jurassic times and has
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