The Falkland Islands are located in the South Atlantic Ocean between 51°S and 53°S on a projection of the Patagonian Shelf, part of the South American continental shelf. In ancient geological time this shelf was part of Gondwana, and around 400 million years ago split from what is now Africa and drifted westwards from it. Today the islands are subjected to the Roaring Forties, winds that shape both their geography and climate.

The Falklands comprise two main islands, West Falkland and East Falkland, and about 776 small islands.^[1]

The geological history of the Falkland Islands began during the Precambrian era more than 1 billion years ago, when Proterozoic granites and gneisses were laid down in Gondwana. These rocks became part of the Cape Meredith/ formation and outcrop at the Cape.^[2] During the Siluro-Devonian era, these rocks were overlain with quartzose and subarkosic sandstones with some siltstone and mudstone, rocks that are particularly erosion- and weather-resistant, giving these parts of the islands a rugged landscape and coastline.^[3]

Tectonic forces continued to form the region: a mountain chain formed, part of which now creates Wickham Heights on East Falkland Island and extends westwards through West Falkland into the Jason Islands. A basin developed and was filled with land-based, or terrigenous, sediments. These layers of sand and mud filled the basin as it sank and as they hardened they produced the rocks of the sedimentary Lafonia Group of the Falklands. These rocks are similar to those in southern Africa's Karoo basin.^[4]

About 290 million years ago, in the Carboniferous period, an ice age engulfed the area as glaciers advanced from the polar region eroding and transporting rocks. These rocks were deposited as extensive moraines and glacial till, or they sank in the sea while the glacier floated in a layer of ice. When the glacial sediments were turned into stone they formed the rocks that now make up the Fitzroy Tillite Formation in the Falklands. Identical rocks are found in southern Africa.^[2]

During the break-up of Gondwana and the formation of the Atlantic Ocean some 200 million years ago, minor crustal fragments that were to become the Falkland Islands detached themselves from the nascent African continent and drifted westwards, dividing and rotating as they did so before settling on the Patagonian Shelf.^[3] Most of the layers of West Falkland and its surrounding islands are slightly inclined from the horizontal. This inclination shows different types of rocks in different places. The quartzites of Port Stephens and Stanley are more resistant than the arenaceous sediments of the formation at Fox Bay. The Hornby Mountains, near Falkland Sound have experienced tectonic forces of uplift and folding which has inclined the quartzite beds of Stanley to the vertical.

Rocks from more recent geological periods such as the Jurassic, Cretaceous, and Tertiary periods usually contain lime-rich rocks. The absence of such rocks has led to an acidic substrate which manifests itself in the nature of the soil.^[3]

The Falkland Islands are an archipelago of 778 islands with an area of 12,173 km² (4,700 sq mi) located in the South Atlantic Ocean on a projection of the Patagonian Shelf. The two principal islands, East Falkland and West Falkland, account for 91% of the land area. These two islands, which have a combined distance of 220 km (140 mi) from east to west and 140 km (87 mi) from north to south, are separated by the Falkland Sound, a channel that averages 20 km (12 mi) in width and has a typical depth of 40 metres (22 fathoms).^[5][6][7] Cape Meredith on West Falkland is about 400 km (250 mi) north-west of the tip of Tierra del Fuego and Westpoint, also on West Falkland and adjacent to West Point Island, is about 500 km (310 mi) from the Patagonian coast. It is believed that at times during the Pleistocene epoch, relative sea level was some 46 metres (151 ft) lower than the present time–sufficient for the sound to be bridged.^[8]

The Falkland Islands have a maritime climate in the transition region between the tundra and subarctic zones (Köppen classifications ET and Cfc respectively) which is characterised by both low seasonal and diurnal temperature ranges and no marked wet and dry season while in the sub-arctic zone the average monthly maximum temperature exceeds 10 °C (50 °F) for no more than four months of the year and the average monthly minimum does not drop below −3 °C (27 °F).^[19] The Falkland Islands climate is very much influenced by both the cool ocean currents and the shielding effect of the Andes.

The cold Antarctic Coastal Current^[20] flows in an easterly direction around Cape Horn where part of it is diverted northwards as the Falklands Current. Subsurface temperatures in the vicinity of the Falklands are of the order of 6 °C. The Falklands Current meets the warm South Brazilian Current at about 40°S (see Brazil–Falkland Confluence), some 1,000 km (620 mi) north of the islands.^[21] The prevailing winds at the Falklands' latitude are the westerlies that gather moisture across the Pacific Ocean, but the Andes form a 4,000 m (13,000 ft) barrier causing a rain shadow across Patagonia and to a lesser extent, the Falkland Islands.^[5]

The January average maximum temperature is about 13 °C (55 °F), and the July maximum average temperature is about 4 °C (39 °F).^{[Note 1]} The rainfall varies between 300 mm in parts of Lafonia to 1400 mm in the mountain ranges^[22] with an average annual rainfall of 573 mm.^[23] Humidity and winds, however, are constantly high. Snow is rare but can occur at almost any time of year. Gales are very frequent, particularly in winter.^[24]

In addition to parts of the Falklands, a maritime subarctic climatic zone is found in parts of coastal Iceland, Faroe Islands, north western coastal Norway, southern islands of Alaska and parts of the Alaskan Panhandle, the southern tip of South America and mountainous areas of Europe including the Scottish Highlands and south-western Norway.^[25]

Biogeographically, the Falkland Islands are classified as part of the Antarctic ecozone^[27] and Antarctic Floristic Kingdom.^[28] Strong connections exist with the flora and fauna of Patagonia in South America.^[15] The only terrestrial mammal upon the arrival of Europeans was the warrah, the loup-renard of Louis Antoine de Bougainville, a kind of fox found on both major islands that became extinct in the mid-19th century.^{[29][30][31][32]} Slater suggests that the warrah was introduced into the Falkland Islands either by rafting or by dispersal of glacial ice during one of the glaciations of the late Pleistocene epoch (2.5 million and 15,000 years ago).^[33]

A total of 14 species of marine mammals have been identified in the surrounding waters:^[34] elephant seal, fur seal and sea lions all breed on the islands with the largest elephant seal breeding site has over 500 animals.^[35] A total of 227 bird species have been seen on the islands,^[15] over 60 of which are known to breed on the islands.^[35] There are two endemic species and 14 endemic subspecies of bird.^[15] Five penguin species including the Magellanic penguin breed on the islands as do over 60% of the global black-browed albatross population.^[34][36]

There are no native reptiles or amphibians on the islands. Over 200 species of insects have been recorded, along with 43 spider species and 12 worm species. Only 13 terrestrial invertebrates are recognised as endemic, although information on many species is lacking and it is suspected up to two thirds of species found are actually endemic. Due to the island environment, many insect species have developed reduced or absent wings. There are around 129 freshwater invertebrates, the majority being rotifer; however, the identification of some species remains in dispute.^[15] Six species of fish are found in freshwater areas, including zebra trout and falklands minnows.^[15]

The islands claim a territorial sea of 12 nautical miles (22 km) and an exclusive fishing zone of 200 nautical miles (370 km), which has been a source of disagreement with Argentina. Different species of krill are found in Falkland waters, with Lobster Krill inhabiting the warmer waters in the north.^[37] The waters around the Falkland Islands are part of the Patagonian Shelf Large Marine Environment. Fin fish that are harvested in the Falkland waters include southern blue whiting (Micromesistius australis), rock cod (Patagonotothen), Blue grenadier or Hoki (Macruronus magellanicus) and the principal species of squid that are harvested are the Illex squid (Illex argentinus) and the Patagonian squid (Loligo gahi).^[38] The squid spawn in the mouth of the Río de la Plata close to the confluence of the cold Falklands current and the warm Brazilian current, migrate southwards along the Patagonian Shelf into the Falklands waters and then return to their spawning grounds along that lies off the continental shelf.^[39]

There are no native tree species on the archipelago, although two species of bushes, fachine and native box are found. Other vegetation consists of grasses and ferns.^[29] Around 363 species of vascular plants, 21 species of ferns and clubmosses and 278 species of flowering plants have been recorded on the islands. Of the vascular plants, 171 are believed to be native and 13 to be endemic.^[15] Some bogs and fens exist, freshwater plants include the soft-camp bog, Astelia pumila (Asteliaceae) dwarf marigold Caltha appendiculata (Ranunculaceae) and gaimardia Gaimardia australis (Centrolepidaceae) and the carnivorous sundew Drosera uniflora (Droseraceae).^[40] Tussac grass, which averages 2 m (6.6 ft) in height but can reach up to 4 m (13 ft), is found within 300 m (1,000 ft) of the coast where it forms bands around larger islands. The dense canopies formed create an insulated micro-climate suitable for many birds and invertebrates.^[41] The pale maiden (Olsynium filifolium) is the islands' proposed national flower.^[35]

Prior to 1812, various colonial powers had small settlements on the Falkland Islands. In that year the islands were abandoned but within twenty years the British had re-established a settlement. In the 1851 census, the settlement's population was recorded as 287, increasing to 2,043 in 1901 and 2,563 in 2012.^{[42][Note 2]}

• Northernmost point – West Jason Cay
• Southernmost point – Beauchene Island
• Westernmost point – West Jason Cay
• Easternmost point – Cape Pembroke
• Highest point – Mount Usborne: 705 m
• Lowest point – Atlantic Ocean: 0 m