Emergence and development of Surtsey

The longest physical feature of this planet is almost certainly the mid-ocean ridge, a narrow deep trench running down the middle of the ocean floors. It has been likened to the seam of a gigantic tennis ball. Magma from deep inside the Earth emerges along the ridge, and the rigid tectonic plates on each side of it gradually move away from one another, as new ocean floor is created on each side of the ridge as the cooling magma becomes lava. The ridge becomes subaerial at one place in the North Atlantic, where the island of Iceland has been formed. On Iceland, continuing activity along the ridge creates new real estate, and Iceland is increasing in area.

In early November 1963, earthquakes were registered some 33 km off the southern coast of Iceland. On the morning of 14 November, 20 km from the nearest large island, Heimaey, of the volcanic Westman Islands, fishermen smelled sulphurous fumes as they were casting their lines, and saw a column of vapour rising from the sea surface not far from their boat.