An archipelago is a set of grouped islands in a given area of the sea surface. The area occupied by an archipelago can be highly variable, as can the number of islands that make it up. In addition to islands, archipelagos can contain other minor land masses such as islets, reefs and keys.
Archipelagos are often linked to volcanic or tectonic activity, although this is not always the case.
Origin of the term
The word archipelago comes from the Greek ἄρχι- –arkhi- ("main") and πέλαγος – pélagos ("sea"). These two Greek words form ἄρχιπέλαγος (achipelagosIn latin archipelagus) and gave rise to archiplegothe ancient name by which the Aegean Sea, the part of the Mediterranean Sea between Greece and Turkey, was known.
In the Aegean Sea there is a high number of islands and islets, about 5000, of which approximately 100 are currently inhabited. The name given to the sea began to be used to refer to the aegean islands and from here it came to be used to refer to any group of islands until reaching the current use of the word archipelago.
Formation and types
The archipelagos are often associated with volcanic activity in subduction zones but can also be the result of erosion, deposition and elevation of land by different geological phenomena such as postglacial adjustment.
Depending on the geological origin, the islands that form the archipelagos can be considered as oceanic islands or continental islands, and in an analogous way the archipelagos can be oceanic or continental.
oceanic archipelagos
Oceanic archipelagos are made up of islands that do not belong to a continental tectonic plate and are mainly of volcanic origin. The formation of oceanic islands and archipelagos is much faster than the formation of continental archipelagos. So is its transformation if there is frequent volcanic activity and environmental phenomena, such as hurricanes, which are more frequent on the high seas.
The Hawaiian archipelago is a good example of an oceanic archipelago. It is formed by the tops of a submarine ridge formed by volcanic activity known as Hawaii-Emperor seamount chain.
continental archipelagos
The landmasses that form the continental islands belong to continental crust but have been separated from the main landmass by tectonic shifts and other geological phenomena, mainly erosion and sedimentary deposition. They are considered exposed continental shelf and their formation is very slow.
Balearic Islands, Greenland or the British Isles are examples of continental archipelagos.