UK geography

from Wikipedia, the free encyclopedia

The United Kingdom consists of the island of Great Britain with England , Scotland and Wales and the north-eastern sixth of the island of Ireland , which is known as Northern Ireland . The area of ​​the country is 244,820 km².

There are several smaller islands and archipelagos around the main island of the United Kingdom . The most important are Shetland and Orkney in the North Sea north of Scotland, the Hebrides in the Atlantic Ocean west of Scotland, Anglesey in the Irish Sea north of Wales, the Isles of Scilly in the Celtic Sea south-west of England and the Isle of Wight off the English coast South coast. The Channel Islands in the English Channel and the Isle of Man in the Irish Sea are politically not part of the United Kingdom. The only land border is on the island of Ireland with the Republic of Ireland , which is around 360 km long. The Eurotunnel connects Great Britain with France .

The main island lies between the 49th and 59th degrees of north latitude (the Shetland Islands reach almost to the 61st degree of latitude) and between the 8th west and 2nd east longitude. The Royal Greenwich Observatory near London is the definition point for the prime meridian .

British Isles satellite photo

physical geography

The UK's physical geography varies widely. It includes the chalk cliffs of Kent and Dorset , the rolling hills of South East England, the granite cliffs of Cornwall , the mountains of Wales , the low mountain ranges of the Peak District and Pennines , the lakes and mountains of the Lake District , the Lowlands , Highlands and Islands of Scotland and the lakes and hills of Northern Ireland. The main island can be geologically divided into two distinct regions along the Tees-Exe Line between the rivers Tees in Yorkshire and Exe in Devon . The north and west are characterized by low mountain ranges made of metamorphic and igneous rocks, the south and east by lowlands and hills made of sedimentary rocks .

The geomorphology of the United Kingdom has been shaped by the combined forces of tectonics and climate change , mainly glaciation during the ice ages . The position of the exact center of the island of Great Britain was calculated in 2002 by the Ordnance Survey . The place Haltwhistle in Northumberland still claims to be in the exact center of the island, but depending on the calculation this is at Wolfhole Crag at Dunsop Bridge or at Whalley in Lancashire .

geology

Topographic map

The geology of the United Kingdom is very complex and consists of many different rock zones with correspondingly diverse landscapes. This diversity and the leading position of British geologists influenced the naming of many geological concepts. These include several names geological epochs such as that under the strain of Ordovizier named Ordovician , named after the homonymous county in southwest England Devonian period and after the tribe of Silures named Silurian -Zeitalter.

The oldest rocks in the United Kingdom are gneisses , dating back to the Archean 2.7 billion years ago. These can be found in the far north west of Scotland and the Hebrides . South of the gneiss formation is a complex composition of rocks in the north-west of the Highlands and in the Grampian Mountains in Scotland and in the mountains of Connemara , Donegal and Mayo in northern Ireland. These are folded sediments that were deposited over the gneiss around 1 billion years ago. A seven-kilometer-thick layer of sandstone was deposited thereon before 800  mya , followed by debris that was transported here by glaciers before 670 mya during the Günz glacial period .

Remnants of ancient volcanic islands form the basis for most of central England, with the rock emerging in some places. Around 600 mya ago, the English and Welsh landscape was piled up into a mountain range, along with the rest of north-western Europe .

The Welsh Skiddaw schist deposits formed about 500 mya ago during the Ordovician. 425 mya ago, north Wales and south County Mayo in Ireland were volcanically active. The remains of these volcanoes are still visible today. Large amounts of volcanic lava and ash (known as Borrowdale Volcanics ) covered both Wales and the Lake District , recognizable by the shape of individual mountains such as Helvellyn and Scafell Pike .

In the Silurian Age 425 to 400 mya, the Caledonian Mountains (see Caledonian Orogeny ) were formed, which covered most of what is now the United Kingdom and were up to 2500 meters high. Deposits of ash and lava from this period can be found in the Mendip Hills and Pembrokeshire . The Ben Nevis , the highest mountain in the British Isles , was created by volcanic deposits in the Devonian period. The sea level varied greatly, which led to the deposition of numerous sedimentary rocks. The Old Red Sandstone from the county of Devon gave this geological epoch its name

During the Carboniferous , around 360 mya ago, the United Kingdom lay on the equator , covered by the shallow Rheic Ocean . At that time limestone was deposited, which is now mainly found in the Mendip Hills and the Pennines . The formation of coal layers in swamps and rainforests also occurred in this age . Coal can be found in many areas of the UK, from Sutherland in the north to Kent in the south. The largest deposits were found in the Midlands , North England and Wales.

During the Permian and Triassic Ages , most of the United Kingdom was again below sea level. This led to the deposition of slate, sandstone, gravel and marl . The seas retreated, leaving a flat desert with salt plains . At the beginning of the Jura , the land was again under water. Sedimentary rocks that now form the bedrock of most of England were deposited, including clay minerals and oolite . The covering of algae and bacteria under the mud of the sea floor led to the formation of oil and gas deposits in the North Sea .

The United Kingdom was again below sea level during the Cretaceous Period , with chalk and flint depositing. These rocks are most visible in the southern English chalk formation , consisting of Salisbury Plain , Chiltern Hills , South Downs , North Downs and other hills.

The last volcanic rocks formed in the early Tertiary 63 to 52 mya. Mighty eruptions shaped the Antrim Plateau and the basalt columns of the Giant's Causeway . Further deposits take place in southern England, the English Channel was a mudflat . The geological changes persisted during the Quaternary ; Advancing glaciers during the ice ages created the typical trough valleys in the mountains and left fertile (but also stony) soil in southern England.

Mountains and waters

Ben Nevis

The ten highest mountains in the United Kingdom are all in Scotland. The highest mountain (also of the British Isles) is Ben Nevis (1345 m  ASL ). The highest point in Wales is the Snowdon (1085 m), in England the Scafell Pike (978 m) and in Northern Ireland the Slieve Donard (849 m). Portions of the Fens in East Anglia are up to 4.6 meters below sea level.

The longest river in the United Kingdom is the Severn , which has its source in central Wales and flows into the Bristol Channel after 354 km in the English county of Gloucestershire . The longest rivers in each state are the Thames in England (346 km), the Tay in Scotland (193 km), the Bann in Northern Ireland (129 km) and the Tywi in Wales (103 km).

The largest lake in the entire British Isles is Lough Neagh in Northern Ireland with an area of ​​381.74 km². In Scotland this is Loch Lomond (71.12 km²), in England the Windermere (14.74 km²) and in Wales Lake Vyrnwy (8.24 km²). The deepest is Loch Morar with 310 meters, followed by Loch Ness with 226 meters. Reservoirs are mainly used to store drinking water, hydropower plants only contribute 2% to electricity production.

As a result of its industrial history, the UK has an extensive network of canals . These emerged for the most part in the early days of the industrial revolution , before they were supplanted by the cheaper railways .

See also:

coast

Territorial claims in the sea
Green:
Territorial waters Light pink: Continental shelf and fisheries
Dark pink: Continental shelf only
Blue: Fisheries only

The length of the British coast is approximately 12,500 km, almost twice as much as e.g. B. the coast of Italy , but about 1100 km less than the coast of Greece .

The coastline is so long because the British Isles consist of hundreds of different islands and the main island of Great Britain is cut by numerous bays. These include Cardigan Bay , Lyme Bay , Bristol Channel , the Thames Estuary , Morecambe Bay , The Wash , the Humber Estuary , Solway Firth , Firth of Clyde , Firth of Forth , Firth of Tay, and Moray Firth . No point in Britain is further than 125 km from the sea.

The UK claims jurisdiction over the continental shelf , an exclusive fishing zone of 200 nautical miles (370.4 km) and territorial waters of 12 nautical miles (22.2 km).

Severe erosion has affected some sections of the UK coastline , particularly Holderness , Norfolk and Suffolk . Numerous settlements like Dunwich sank into the sea. In other places the land could be wrested from the sea; B. in the Fens , Somerset Levels and Romney Marsh .

Islands

In total, the United Kingdom consists of more than 1000 small islands . Among them are some artificially created crannógs . The most important of these archipelagos and islands are listed below:

See also

swell

  1. ^ Stuck in the middle with ewe BBC News October 20, 2002
  2. ↑ Ordnance MapZone Question: Where is the center of mainland Great Britain?

Web links

Commons : Geography of the United Kingdom  - collection of images, videos and audio files