Enquiry question 1: Why are coastal landscapes different and what processes cause these differences?
2B.1 Key idea: The coast, and wider littoral zone, has distinctive features and landscapes.
a. The littoral zone consists of backshore, nearshore, and offshore zones, including a wide variety of coastal types and
is a dynamic zone of rapid change.
The Littoral Zone
A coast is a strip of land where the sea meets the
land. It is divided into zones depending on what the
conditions are like on different sections of a coast.
These are dynamic places that experience constant
and rapid change.
Backshore: above high tide level. It is only
affected by waves during exceptionally high tides
(called max spring tides) and during major storms.
Foreshore: this is the area lying between the high tide mark and the low tide mark. This is where wave
processes will occur.
Nearshore: these are shallow waters. This zone is often one for intense marine activity, such as fishing and
leisure. Also forms part of the physical system of the coastline through transfers of sediment by currents
close to the shore.
Offshore: the area beyond the point where waves cease to impact the sea bed and in which activity is
limited to the deposition of sediments (sediment is dropped by waves because they have less energy).
The littoral zone varies because of short term factors, such as wave type, daily tides and seasonal storms, and long
term factors such as changes to sea levels and climate change.
b. Coasts can be classified by using longer term criteria such as geology and changes of sea level or shorter term
processes such as inputs from rivers, waves and tides.
The coastline as a system
Inputs Processes Outputs
People – human activity, coastal Erosion – wearing away of material Erosional landforms – arch, stack,
management Mass movement – movement of headland
Marine – waves, tides, storm surges surface material Different types of coast –sandy
Atmospheric – weather/climate, climate Transport – movement of beaches, coastal wetlands
change, solar energy sediment Depositional landforms – spits,
Land – rock type and structure, tectonic Deposition tombolos, beaches
activity Weathering
Ways of classifying coasts
Geology Can create rocky, sandy and estuarine coasts, as well as concordant and discordant coasts
Relative sea Emergent coasts: where coasts are rising relative to sea level.
level change Submerging coasts: where the coast is being flooded by the sea.
Wave energy Low energy sheltered coasts with limited fetch and low wind speeds resulting in small waves.
High energy exposed coasts, facing prevailing winds with long fetches resulting in powerful waves.
Balance… …between erosion and deposition – creating either erosional or depositional coasts and their
associated features.
But no classification system is definitive. E.g. Cornwall’s high-energy coast is mainly rocky, but also has long stretches
of sand and some estuaries.
, c. Rocky coasts (high and low relief) result from resistant geology, often in high-energy environment, whereas coastal
plain landscapes (sandy and estuarine coasts) are found near areas of low relief and result from supply of sediment
from different terrestrial and offshore sources, often in low energy environment.
Resistant rock coastlines
Rocky coastlines can withstand frequent winter storms without suffering rapid erosion e.g. Cornwall. Much of
Cornwall’s coastline consists of older resistant geology such as igneous rocks (basalt and granite) and metamorphic
rocks (such as slates and schists).
Rocky coasts are generally found in high-energy environments. In the UK, these tend to be Atlantic facing coasts
where waves are powerful due to a large fetch. Thus, the rate of erosion exceeds the rate of deposition. Erosional
landforms such as headlands, cliffs and wave-cut platforms tend to be found in these environments.
Rocky coasts can be found at high and low relief. Where marine erosion by wave action dominates, cliffs tend to be
steep (high relief) and there is little in the way of rock debris at the base of the cliff because it is quickly broken down
by erosion and carried away by waves. Cliffs which are not actively eroded at their base by waves have shallower
curved profiles and lower relief – sub-aerial processes of surface run off erosion and mass movement move rock and
sediment downslope.
Coastal plain landscapes
Estuarine coasts: e.g. The Wash estuary is an area of low, flat relief – referred to as a coastal plain. The estuary is
shaped when the four rivers mix with the sea water to form mud-flats, salt marshes and lagoons.
Sandy beaches: e.g. Bamburgh beach.
Estuarine and sandy coastlines are generally found in low-energy environments and at low relief (south-east side of
the Tees-Exe Line). This is because the waves tend to be less powerful due to smaller fetches, or where the coast is
sheltered from large waves. This results in the rate of deposition exceeding the rate of erosion, leading to landforms
such as beaches, spits and salt marshes.
Coastal plain landscapes result from the supply of sediment from different terrestrial and offshore sources. For
example, The Wash has multiple sources if sediment. For example, the erosion from the Holderness coastline
provides sediment which travels southwards in suspension and some sediment comes from tidal currents, which pick
up glacial deposits from the shallow sea floor. The fact that sediment comes from two different directions – from the
north and east – illustrates what are known as sediment cells. The Wash and the Norfolk coastline form part of one
of 11 sediment cells around the English and Welsh coasts.
2B.2 Key idea: Geological structure influences the development of coastal landscapes at a variety of scales.
a. Geological structure is responsible for the formation of concordant and discordant coasts.
Concordant and discordant coasts
Concordant Discordant
These are generated when rock strata run parallel to the When different rock strata intersects the coast at an
coastline. angle, usually perpendicular.
Erosional landforms: coves and wave cut platforms Erosional landforms: headlands and bays
