Why nowhere in Britain is far from the sea

What the country is made of

The United Kingdom occupies the major part of the British Isles archipelago, comprising the island of Great Britain, the north-eastern part of the island of Ireland, and a large number of smaller islands. Its area is 242,495 square kilometres on the record used here, and it lies off the north-western coast of continental Europe between latitudes 49° and 61° north.

Almost everything about the country follows from the sea. The coastline measures about 12,429 kilometres, and it is indented heavily enough that no location in the United Kingdom is more than 125 kilometres from tidal waters. A population that has never been far from the sea produced a naval and trading history that a continental country of the same size could not have had.

The single land border is between Northern Ireland and the Republic of Ireland and runs 499 kilometres, and Northern Ireland has 650 kilometres of coastline of its own.

Where the high ground is

The physical geography varies sharply between the four countries. England is mostly lowland, with upland or mountainous terrain found only north-west of a line drawn from the Tees to the Exe, and the uplands it does have are the Lake District, the Pennines, the North York Moors, Exmoor and Dartmoor. The lowlands are traversed by ranges of low hills, frequently composed of chalk, and by flat plains.

Scotland is the most mountainous of the four and its geography is organised by a single structural feature. The Highland Boundary Fault runs across the Scottish mainland from Helensburgh to Stonehaven and separates two entirely distinct terrains, the Highlands to the north and west and the Lowlands to the south and east. Almost every generalisation about Scottish land, settlement and history is really a statement about which side of that line something is on.

Each country has its own summit and they descend in a clear order: Ben Nevis in the Grampians at 1,345 metres in Scotland, Snowdon in Eryri at 1,085 metres in Wales, Scafell Pike in the Cumbrian Mountains at 978 metres in England, and Slieve Donard in the Mournes at 852 metres in Northern Ireland.

None of those figures is large by continental standards, and the terrain they describe is harder than the heights suggest, because the weather arrives off the Atlantic and the ground rises straight out of sea level rather than off an already elevated plateau. The named ranges are numerous for a country this size. Scotland alone holds the Cairngorms, the Highlands, the Southern Uplands, the Grampians, the Monadhliath, the Ochils, the Campsie Fells and the Cuillin, and Wales holds Eryri, the Cambrian Mountains, the Brecon Beacons, the Clwydian and Preseli hills and the Black Mountains.

What the ice did

The overall shape of the land was produced by tectonics and by climate, and in the north and west specifically by glaciation. The major changes of the last two million years came from a series of ice ages, and the most severe of them was the Anglian Glaciation, with ice up to 1,000 metres thick reaching as far south as London and Bristol between roughly 478,000 and 424,000 years ago.

That glaciation did something no other event in British physical history matched: it diverted the course of the Thames. A river system was rerouted by ice, and the valley the capital now sits in is a consequence of where the ice stopped.

The rest of the glacial legacy is visible everywhere north and west of the ice limit. The Lake District's valleys, the Scottish lochs, the Welsh cwms and the drowned coastlines of the west are all glacial, and the soils and drainage of the whole northern half of the country were reset by the same process.

South and east of the limit the landscape is older and gentler, which is why the arable farming, the largest cities before the industrial revolution and the earliest settlement are all concentrated there. The ice line is therefore also a settlement line, and it runs roughly where the population density map still changes today.

Why the rock changes so quickly

For a country of this size the geological variety is remarkable, and the reason is that Britain has travelled a long way. By the end of the Carboniferous period the continents had fused into the supercontinent of Pangaea, and Britain sat in its interior under a hot arid desert climate with flash floods that left the beds of red sedimentary rock still visible across the Midlands and the south-west.

The land has since been at almost every latitude and under almost every climate, and each period left a deposit. The result is that the rock beneath the surface changes over distances measured in kilometres rather than in hundreds of them, and the ages represented run from some of the oldest rock in Europe in the north-west of Scotland to comparatively recent deposits in the south-east.

That variety is why the industrial revolution happened here rather than somewhere else. Coal, iron ore, limestone and water power occurred close enough together to be combined without long-distance transport, in a country whose rivers were navigable and whose coast was never far away.

The same variety produced the soils, and through them the agricultural map. The chalk downs of the south, the clay vales, the granite uplands of the south-west and the thin acid soils of the north and west each support a different kind of farming, and the difference between arable England and pastoral Wales and Scotland is a fact about rock before it is a fact about anything else.

How the islands are arranged

Great Britain is the largest island in the archipelago and holds England, Scotland and Wales. Northern Ireland occupies the north-eastern corner of the second island. Everything else is smaller, and there are a great many of them.

The northern and western island groups are the ones that shape Scottish geography and history: the Hebrides along the Atlantic coast, Orkney off the north-east tip and Shetland further north still, closer to Norway than to Edinburgh. They carry Norse place names, a separate settlement history and, in Orkney, the Neolithic monuments inscribed on the World Heritage List.

The Isle of Wight, the Isles of Scilly and Anglesey are the notable southern and western islands, and the Isle of Man and the Channel Islands are not part of the United Kingdom at all but crown dependencies with their own legislatures, which is a constitutional distinction with real practical consequences for law, tax and travel.

The consequence of an archipelago rather than a landmass is that internal transport has always required either a crossing or a long detour, and the ferry networks of western Scotland remain public services rather than tourist operations because there is no alternative for the people who live at the end of them.

Where the water goes

The longest river is the Severn, which rises in Wales and flows into England. The largest lake by surface area is Lough Neagh in Northern Ireland, while Loch Ness in Scotland holds the largest volume of water, which is a useful illustration of the difference between a shallow lowland lake and a deep glacial trench.

The rivers are short by continental standards and were long enough to matter. Every major British city sits on one, because before railways a navigable river was the condition of a port and a port was the condition of a city, and the industrial revolution then attached canals to the same network.

Rainfall is distributed unevenly and the pattern is simple: the west is wetter than the east. Atlantic weather systems arrive from the south-west, rise over the uplands of Wales, north-west England and western Scotland, and drop most of their water there, leaving the eastern side of the country in a rain shadow dry enough that parts of East Anglia need irrigation.

What the climate is and why

The climate is generally temperate, with significant local variation caused mainly by altitude and distance from the coast. Two gradients govern it. The south is warmer than the north, which follows from latitude across almost eight degrees, and the west is wetter than the east, which follows from the prevailing wind.

The reason the country is habitable at all in the way it is comes from the ocean. The warming influence of the Gulf Stream makes the United Kingdom significantly warmer than other places at similar latitudes, and the comparison usually offered is Newfoundland, which sits at roughly the same distance from the equator and has a far harsher climate.

The maritime influence also compresses the range. Winters are cool rather than cold and summers warm rather than hot across most of the country, extremes in either direction are rare, and the day-to-day variability is high because the weather arrives from the Atlantic in a sequence of systems rather than settling into a season.

The practical consequence for anything that depends on weather is that altitude and distance from the coast matter more than latitude. The Cairngorms hold snow when the coast forty kilometres away does not, and the difference between the two is a thousand metres rather than a degree of latitude.

What the sea is worth

The United Kingdom claims jurisdiction over its continental shelf as defined in continental shelf orders or by agreed boundaries, an exclusive fishing zone of 200 nautical miles, and a territorial sea of 12 nautical miles. Its exclusive economic zone in Europe covers 773,676 square kilometres, more than three times the land area.

Including the crown dependencies and the overseas territories the figure becomes 6,805,586 square kilometres, spread across the Atlantic, the Caribbean, the South Atlantic, the Indian Ocean and the Pacific. A country of moderate land area holds maritime rights on a scale that follows entirely from what the empire left behind.

The economic content of that zone has changed twice in living memory. North Sea oil and gas made the country a hydrocarbon producer from the 1970s, and the same shallow shelf seas are now being built out with offshore wind, so the asset has been converted rather than exhausted.

Fisheries are the third use and the most politically charged, because access to the zone was negotiated inside the European Union for four decades and has been renegotiated since departure. A resource that is small in economic terms and large in political ones is a recurring feature of British coastal geography. Fishing employs a small fraction of the workforce and occupies a large share of the argument, because the communities it supports are concentrated in places with few other employers and because the sea has a standing in national self-description that its economics do not justify. United Kingdom: economy covers what the North Sea is now producing and United Kingdom: travel the coasts a visitor would actually go to.