Britain is a maritime nation, surrounded by the sea. We have a coastline more than 3000km long.
Even so, there are many pressures from competing and conflicting interests:

• ports and terminals
• port-related industry
• towns
• recreation
• fishing
• energy generation
• wildlife and conservation

In all of these, coastal erosion, deposition and changes in sea level have played their part.

COASTAL EROSION

To add to the problem of pressure on land use, some of this precious coastal land is disappearing as a result of coastal erosion.

How does the sea erode the coast? Can it be prevented? How much of this erosion is natural, and how much is our fault? If we try to stop erosion, how does the sea respond? It is very expensive trying to hold back the sea. Is it worth the cost? Is it better to live with, and plan for, the consequences of erosion?

COASTAL DEPOSITION

Compared with erosion, the effects of coastal deposition are not so widely reported. Deposition is more gradual and less dramatic - there are no pictures to be had of buildings perched precariously on the edge of a cliff - or even half way down it! On balance, however, it is suggested that we are gaining more land by deposition than we lose to erosion.

What happens if we interfere with the processes of deposition? What are the consequences of extracting sand from the beach? The sea needs the sand as much as we do; how does the sea respond if we dig it up?

As an alternative view, consider the land areas which were added to Britain by glacial deposition, for example, Holderness on the coast of East Yorkshire. The sea is now merely taking away the land which was added to the coastline by glaciers, restoring it to the earlier pre-glacial shape.

CHANGES IN SEA LEVEL

Land can also be lost by a (relative) rise in sea level which may be due to

• more water in the oceans (from melting ice caps)
• subsidence of the land (which is still affecting south eastern England).

Any future rise in sea level will affect all coastal settlements, particularly as the town centres (and administrative hubs) tend to be in the lower lying areas.

Change in sea level is nothing new. The limestones which now form hills in Derbyshire and Yorkshire were deposited under the sea and have been uplifted since then (probably more than once).

More recently, fluctuations in sea level during and since the Ice Age have left their mark:

raised beaches provide areas of flat, coastal land in otherwise hilly areas estuaries and fjords provide sheltered, natural harbours

What effect will human interference have on these natural changes, for example as a result of global warming? What plans do we need to make to take these changes into account?

THE WORK OF THE SEA

The energy required for erosion of the cliffs and the transport of eroded material comes from the sea. The origin of the energy may be winds hundreds of kilometres away, transferred across the ocean by waves which then break on our coastline.

The work of the sea mainly involves waves, which transfer the energy (the water particles stay in the same average position) breakers (or breaking waves), which transfer the water itself, causing erosion and transport. but also currents and tides.

THE COAST OF BRITAIN

With such a long coastline, it is not surprising that the coast of Britain displays a wealth of landforms and other features associated with marine erosion and deposition.

But don’t forget - if you have recently bought an Ordnance Survey map of any of these coastal areas, it is already out of date - the coast is always changing!

The Study Topics

• Marine Erosion
• Marine Deposition
• Changes in Sea Level
• The Work of the Sea
• The Coast of Britain

are included in the Geopix "Coasts" Study Guide.

To order the "Coasts" Study Guide please visit the Geopix Online Store