<span>If you see a very tall, rock feature that looks like a jagged, rectangular block sticking out of the ground, you're probably observing a volcanic neck. Also known as a lava neck or volcanic plug, a volcanic neck is formed when magma solidifies within a vent of an active volcano. This can harness great amounts of pressures which could lead to an explosive eruption.</span>
A shield volcano<span> is a type of volcano usually built almost entirely of fluid magma flows</span>
In other words: they sailed from Hennø in Norway, heading due west towards Greenland, between Shetland and the Faroes and south of Iceland
<h2>Answer: Atoll</h2>
An atoll is an oceanic coral island, usually in the shape of a circular ring, which may be completely or partially closed. It is also called by this term to the set of several small islands that are part of a coral reef, with an interior lagoon that generally communicates with the sea.
Atolls are formed when a coral reef grows around an oceanic volcanic island, as the island sinks into the ocean and disappears underwater, the growth of the coral increases until reaching the sea level, where the action of the wind and the waves erode it and transform it into sand.
It should be noted that this process can take millions of years.
In this sense, the Maldives, an island country located in the Indian Ocean (southwest of Sri Lanka and a few kilometers from India), has these characteristics.
Its territory is organized in 26 atolls and as a country it is constituted by some 1200 islands.
