South Sandwich Islands

The South Sandwich Islands (Islas Sandwich del Sur) are a chain of uninhabited volcanic islands in the South Atlantic Ocean. They are administered as part of the British Overseas Territory of South Georgia and the South Sandwich Islands. The chain lies in the sub-Antarctic region, about 700 km southeast of South Georgia and 1700 km northeast from the tip of the Antarctic Peninsula.

The archipelago comprises 11 main islands forming an island arc running north–south, the largest being Montagu at 110 km2. It is divided into four groups, from north to south: The Traversay, Candlemas and Central Islands (Saunders, Montagu, and Bristol), and Southern Thule.

The archipelago is prone to violent earthquakes. Over the previous century, nine M 7+ earthquakes have occurred here, the most recent being the M 8.1 in August 2021. None of these earthquakes are known to have caused fatalities due to their remote location.

History
The southern eight islands of the Sandwich Islands Group were discovered by James Cook in 1775. The northern three were discovered by Fabian Gottlieb von Bellingshausen in 1819.

Departing from South Georgia, Captain Cook sailed to the southeast to discover Clerke Rocks and a group of islands which he named "Sandwich Land" in honour of Lord Sandwich, then First Lord of the Admiralty. The word "South" was later added to distinguish them from the "Sandwich Islands", now known as Hawai'i.

The Traversay Islands (Zavodovski, Leskov and Visokoi) were discovered by the Imperial Russian Navy expedition of Bellingshausen and Lazarev in the ships Vostok and Mirny in 1819.

The United Kingdom formally annexed the South Sandwich Islands through letters patent in 1908, grouping them with other British-held territory in Antarctica as the Falkland Islands Dependencies.

Argentina claimed the South Sandwich Islands in 1938 and challenged British sovereignty in the islands on several occasions. From 25 January 1955 through the summer of 1956 Argentina maintained the summer station Teniente Esquivel at Ferguson Bay on the southeastern coast of Thule Island. From 1976 to 1982, Argentina maintained a naval base named Corbeta Uruguay in the lee (southern east coast) of the same island. Although the British discovered the presence of the Argentine base in 1976, protested, and tried to resolve the issue by diplomatic means, no effort was made to remove them by force until after the Falklands War. The base was eventually removed on 20 June 1982 and the installations were demolished in December of that year.

Since 1995, the South African Weather Bureau has maintained two automatic weather stations on the islands of Zavodovski and Thule.

The territory of "South Georgia and the South Sandwich Islands" was formed in 1985; previously, both archipelagos had been governed as part of the Falkland Islands Dependencies.

On 10 February 2008, an earthquake of magnitude 6.5 on the Richter Scale had its epicenter 205 km south-southeast of Bristol Island. On 30 June 2008, an earthquake of magnitude 7.0 struck the region. Its epicenter was at 283 km east-northeast (73 degrees) of Bristol Island.

Geography
The northernmost of the South Sandwich Islands form the Traversay Islands and Candlemas Islands groups, while the southernmost make up Southern Thule. The three largest islands – Saunders, Montagu, and Bristol – lie between the two. The Islands' highest point is Mount Belinda (1370 m) on Montagu Island. The fourth highest peak, Mount Michael (990 m) on Saunders Island has a persistent lava lake, known to occur at only eight volcanoes in the world.

The South Sandwich Islands are uninhabited, though a permanently staffed Argentine research station was located on Thule Island from 1976 to 1982 (for details, see above). Automatic weather stations are on Thule Island and Zavodovski. To the northwest of Zavodovski Island is the Protector Shoal, a submarine volcano.

The South Sandwich Islands from north to south are:

A series of six passages separates each of the islands or island groups in the chain. They are, from north to south: Zavodovski Isl., Traverse passage, Visokoi Isl., Brown's passage, Candlemas Isl., Shackleton's passage, Saunders Isl., Larsen's passage, Montagu Isl., Biscoe's passage, Bristol Isl., Forsters Passage, Southern Thule. Nelson Channel is the passage between Candlemas and Vindication islands.