List of Shetland islands
This is a list of Shetland islands in Scotland. The Shetland archipelago is located 100 kilometres (62 mi) north of mainland Scotland and the capital Lerwick is almost equidistant from Bergen in Norway and Aberdeen in Scotland. The Shetland archipelago comprises about 300 islands and skerries, of which 16 are inhabited. In addition to the Shetland Mainland the larger islands are Unst, Yell and Fetlar.
The definition of an island used in this list is that it is land that is surrounded by seawater on a daily basis, but not necessarily at all stages of the tide, excluding human devices such as bridges and causeways. There are four islands joined to the Shetland Mainland by bridges, East Burra, West Burra, Trondra, and Muckle Roe. There is also a bridge from Housay to Bruray. Nowhere in Shetland is more than three miles (5 km) from the sea. Mavis Grind (Old Norse for "gate of the narrow isthmus") is a narrow neck of land little more than 100 metres (328 feet) wide separating St. Magnus Bay and the Atlantic in the west from Sullom Voe and the North Sea in the east.
The geology of Shetland is complex with numerous faults and fold axes. These islands are the northern outpost of the Caledonian orogeny and there are outcrops of Lewisian, Dalradian and Moine metamorphic rocks with similar histories to their equivalents on the Scottish mainland. Similarly, there are also Old Red Sandstone deposits and granite intrusions. The most distinctive feature is the ultrabasic ophiolite, peridotite and gabbro on Unst and Fetlar, which is a remnant of the Iapetus Ocean floor. Much of the island's economy depends on the oil-bearing sediments in the surrounding seas. In the post-glacial epoch, c. 6200 BC, the islands experienced a tsunami up to 20 metres high caused by the Storegga Slides, an immense underwater landslip off the coast of Norway.
The islands all fall within the Shetland Islands Council local authority. They have been continuously inhabited since Neolithic times and experienced Norse rule for several centuries, the first written records being the Norse sagas. The excavations at Jarlshof near the southern end of the Mainland have provided archaeological evidence of life in Shetland since Bronze Age times and the annual Up Helly Aa fire festivals are a living reminder of Shetland's Viking past. The archipelago is exposed to wind and tide and there are numerous lighthouses as an aid to navigation. A small wind farm in Shetland recently achieved a world record of 58% capacity over the course of a year. The indigenous Shetland ponies are reputed for their strength and hardiness.