Scotia Arc is the island arc

Island arc

An island arc is a type of archipelago composed of a chain of volcanoes which alignment is arc-shaped, and which are situated parallel and close to a boundary between two converging tectonic plates....

 system forming the north, east and south border of Scotia Sea

Scotia Sea

The Scotia Sea is partly in the Southern Ocean and mostly in the South Atlantic Ocean.-Location and description:Habitually stormy and cold, the Scotia Sea is the area of water between Tierra del Fuego, South Georgia, South Sandwich Islands, South Orkney Islands and the Antarctic Peninsula, and...

. The arc comprises submarine ridges and the island groups of South Orkneys

South Orkney Islands

The South Orkney Islands are a group of islands in the Southern Ocean, about north-east of the tip of the Antarctic Peninsula. They have a total area of about ....

, South Sandwich Islands, Clerke Rocks

Clerke Rocks

The Clerke Rocks are a group of small rocky islands some southeast of South Georgia that extend from east to west. The Clerke Rocks include The Office Boys at the northeastern end and Nobby at the southeastern end of the group...

, South Georgia, Shag Rocks, Isla de los Estados

Isla de los Estados

Isla de los Estados is an Argentine island that lies off the eastern extremity of the Argentine portion of Tierra del Fuego, from which it is separated by the Le Maire Strait...

, and Burwood Bank http://findarticles.com/p/articles/mi_qa3721/is_199811/ai_n8823602 linking the mountains of Antarctic Peninsula

Antarctic Peninsula

The Antarctic Peninsula is the northernmost part of the mainland of Antarctica. It extends from a line between Cape Adams and a point on the mainland south of Eklund Islands....

 to those of Tierra del Fuego

Tierra del Fuego

Tierra del Fuego is an archipelago off the southernmost tip of the South American mainland, across the Strait of Magellan. The archipelago consists of a main island Isla Grande de Tierra del Fuego divided between Chile and Argentina with an area of , and a group of smaller islands including Cape...

 (specifically the Mitre Peninsula

Mitre Peninsula

Mitre Peninsula is the easternmost part of Isla Grande de Tierra del Fuego, located in the very southeast of the island, with its easternmost point, Cabo San Diego, 29 km northwest of Isla de los Estados, from which it is separated by Le Maire Strait. In the south, the peninsula is bounded by the...

) and the Andes

Andes

The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...

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The arc is related to the subduction

Subduction

In geology, subduction is the process that takes place at convergent boundaries by which one tectonic plate moves under another tectonic plate, sinking into the Earth's mantle, as the plates converge. These 3D regions of mantle downwellings are known as "Subduction Zones"...

 of the South American Plate

South American Plate

The South American Plate is a continental tectonic plate which includes the continent of South America and also a sizeable region of the Atlantic Ocean seabed extending eastward to the Mid-Atlantic Ridge....

 to its east under the South Sandwich Plate

South Sandwich Plate

The South Sandwich Plate or microplate is a tectonic plate bounded by the subducting South American Plate to the east, the Antarctic Plate to the south and the Scotia plate to the west.The South Sandwich Islands are located on this small plate.- References :...

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