South Uist (, ; ) is the second-largest island of the Outer Hebrides in Scotland. At the 2011 census, it had a usually resident population of 1,754: a decrease of 64 since 2001. The island, in common with the rest of the Hebrides, is one of the last remaining strongholds of the Gaelic language in Scotland. South Uist's inhabitants are known in Gaelic as Deasaich (Southerners). The population is about 90% Roman Catholic.
The island is home to a nature reserve and a number of sites of archaeological interest, including the only location in the British Isles where prehistoric mummies have been found. In the northwest, there is a missile testing range. In 2006 South Uist, together with neighbouring Benbecula and Eriskay, was involved in Scotland's biggest-ever community land buyout by Stòras Uibhist. The group also owns the "biggest community wind farm in Scotland", Lochcarnan, on South Uist which opened in 2013.
Geology
In common with the rest of the Western Isles, South Uist is formed from the oldest rocks in Britain, Lewisian gneiss brought to the surface by old tectonic movements. They bear the scars of the last glaciation which has exposed many of them. The rocks had high-grade regional metamorphism around 2,900 million years ago: in the Archaean eon. Some show granulite facies metamorphism, but most have slightly cooler amphibolite facies. A number of metabasic bodies and metasediments occur locally in the gneiss.
On the east side of the island between Lochboisdale and Ornish – part of the Outer Hebrides Thrust Zone – is the Corodale gneiss, dominated by garnet-pyroxene rock. A narrow zone of pseudotachylyte occurs along its western margin with the regular gneiss. The Usinish peninsula is formed from ‘mashed gneiss’, within which the banding has mainly been destroyed. Between these two gneisses is a band of mylonite (as offshore on Stuley). Mashed gneiss occurs again in the extreme southeast. Small occurrences of Archaean granites are found in the centre of the island.
The island is traversed by many normal faults: E to W, to NNW to SSE, many being NW to SE. Numerous NW to SE dykes cut through the island: quartz-dolerite, camptonite and monchiquite dykes of Permo-Carboniferous age and later Palaeogene tholeiitic dykes. More recent geological deposits include blown sand along the northern and western coasts and peat inland along with some (glacial) till.
Geography
The west is machair (fertile low-lying coastal plain) with a continuous sandy beach, whilst the east coast is mountainous with the peaks of Beinn Mhòr (Gèideabhal) at and Hecla at . The island is linked to Eriskay and Benbecula by causeways.
The landscape is characterised by numerous lochs and lochans, the largest of which is Loch Bì.
The main village on the island is Lochboisdale (Loch Baghasdail), from which Caledonian MacBrayne operates ferries to Mallaig (Malaig) on the Scottish mainland (some sailings to Oban in winter when the only large vessel able to dock at Mallaig, MV Lord of the Isles, is covering elsewhere on the Calmac network for vessels in drydock, or in drydock herself). The company previously operated services to Castlebay (Bàgh a' Chaisteil) on Barra, however as of the 2016 fleet reshuffle these have been removed. There is a separate service to Ardmhòr (Barra) operating from Eriskay numerous times a day. (Smaller settlements include Daliburgh (Dalabrog), Howmore (Tobha Mòr) and Ludag (An Lùdag).
Climate
South Uist has an oceanic climate (Köppen: Cfb).
Etymology
Mac an Tàilleir (2003) suggests that the derivation of Uist may be "corn island". However, whilst noting that the vist ending would have been familiar to speakers of Old Norse as meaning "dwelling", Gammeltoft (2007) says that the word is "of non-Gaelic origin" and that it reveals itself as one of a number of "foreign place-names having undergone adaptation in Old Norse". In contrast, Clancy (2018) has argued that Ívist itself is an Old Norse calque on an earlier Gaelic name, *Ibuid or Ibdaig, which corresponds to Ptolemy’s Eboudai. Coates (2006) linked the names Uist and Ibiza, an island in the Mediterranean, arguing for an origin in Semitic *bšm ("balsam") with the island-naming prefix *’y, acknowledging the possibility of a name transfer and the name being subject to the influence of Norse ívist.