Scientists have revealed details of the world's most extreme deep-sea volcanic vents, 3.1 miles down in a rift in the seafloor of the Caribbean. The undersea hot springs, which lie half a mile deeper than any seen before, may be hotter than 450C and are shooting a jet of mineral-laden water two-thirds of a mile into the ocean above. The vents are nicknamed 'black smokers' for the smoky-looking hot fluids, laden with mineral particles, that gush from them

Photograph: University of Southampton/NOC