GEOGRAPHY IGCSE: THE HOLDERNESS COASTLINE. It contains: main facts, eroding coast Europe, long shore drift, features of the Holderness coastline, management, coastline defense.

1. IGCSE GEOGRAPHY
EXTRA WORK
THE HOLDERNESS COASTLINE

2. The Holderness Coastline is
located in the North of
England, between the Humber
Estuary in the south and a
headland at Flamborough.
It has the reputation as the
number one place in Europe
for coastal erosion, and in a
stormy year waves from the
North sea can remove
between 7-10m of coastline.

3. It is one of the fastest eroding
coastlines in Europe as a result
of it’s geology.
The coastline starts with
blowholes, stacks and stumps
at Flamborough, and
culminates with Spurn head, a
very large spit that runs across
part of Humber Estuary.

4. The Holderness coastline suffers the
highest rate of coastal erosion in Europe:
1.5 m a year on average or 2 million
tonnes of material a year.
Some of this is transported by longshore
drift with 3% of material being deposited
at Spurn Point spit, to the south.
The growth of Spurn Point is
demonstrated by a series of lighthouses
that have been built on the point.
5 km of land has been lost since the
Roman era, including at least 23
towns/villages, including Ravenspurn.

5. The Holderness coastline is
susceptible to erosion due
to the long north-easterly
fetch, allowing for powerful
waves, and the softness of
the geology that make up
the cliffs.
Holderness is also a former
bay that was filled in during
the last ice age and is now
made up of chalk/glacial
compounds that are easily
eroded such as boulder
clay.

6. The geology runs in bands, with a chalk layer at Flamborough in
the North, Boulder clay or till (laid down in the last ice age)
south of that and finally river deposits in the Humber Estuary.
Because the clay is an unconsolidated WEAK mass of clay
particles and boulders it erodes more rapidly than the more
resistant rock of chalk in the north.
The processes of erosion and weathering occurring are
numerous but include hydraulic action, freeze thaw, abrasion,
solution and carbonation.

8. This has left a bay where the clay is and a headland jutting out
to sea at Flamborough head.
Wave refraction focuses the waves energy on the layered and
faulted rocks of Flamborough head, eroding the calk, the
incredibly weak nature of the clay still means that it erodes
faster than the chalk.
The chalk headland has stumps and blowholes.

9. The coastline today is around 4km inland from where it was in
Roman times, and there are many lost villages of the
Holderness coastline that have long disappeared into the sea.
Farmland, tourist sites such as caravan parks and villages
remain under threat.
The weak clay, stormy nature of the North Sea, and rising sea
levels of 4mm per year mean that the future is bleak for parts
of this coastline.
In addition to the clay being vulnerable to erosion, it is also
prone to slumping (lean, sit).
This is because water enters cracks and pore spaces in the rock,
adding weight and making it slump.

11. There is a debate about whether or not human beings should
attempt to defend coastlines.
In the case of the Holderness coastline, its geology (weak clays)
waves (destructive during North Sea storms) and
geomorphology (the shape of the coastline allows the waves to
break at the base of the cliffs) make erosion almost inevitable.

12. Mappleton is a small village that could
become village number 30 lost to the sea.
The road running through it, the B1242 links
towns along the coastline and would have
been lost to coastal erosion if protection
measures were not put into place.
It was decided that the cost of coastal
defence for a village of only 100 people was
less than the cost of building a new road. So,
blocks of granite were brought in and placed
along the cliff base and 2 rock groynes were
put into place to trap sediment moving
because of longshore drift.

13. PROMENADE AT BRIDLINGTON
At Bridlington, the town is protected by a 4m high stone sea-wall. The purpose of this is to reflect the waves and
prevent them from eroding the soft material of the cliffs. This is also an attraction to tourists who can walk along the
sea-front, and gain access to the beach. The beach is protected by groynes - wooden barriers which prevent long-shore
drift from moving the sand along the coast.

14. CLIFF EROSION AT BARMSTON
Near Barmston the cliffs are formed of soft glacial till - mainly sandy beds. They are easily eroded by wave action, and
slope process like gullying and mass movement. The cliff is retreating at a rapid rate - up to 6m per year.

15. VIEW SOUTH AT BARMSTON
Near Barmston the cliffs are formed of soft glacial till - mainly sandy beds. The narrow beach means that they are
easily eroded by wave action. Mass movement contributes many tons of soft material onto the beach, and it is washed
southwards by longshore drift. The cliff is retreating at a rapid rate - up to 6m per year.

16. SEA DEFENCE AT HORNSEA
At Hornsea, the town is protected by a concrete sea-wall. The purpose of this is to reflect the waves and prevent them
from eroding the soft material of the cliffs. The beach is protected by groynes - wooden barriers which prevent long-
shore drift from moving the sand along the coast.

17. SEA DEFENCE AT MAPPLETON
The sea defence at Mappleton was designed to cut down the erosion. This would protect the village of Mappleton and
the main coastal road which passes within 20 metres of the cliff top. The profile of the cliff was made gentler, and
large boulders (called 'rock armour') were placed along the foot of the cliff, to break the waves.

18. SEA DEFENCE AT MAPPLETON
The sea defence at Mappleton was designed to cut down the erosion. Large boulders (called 'rock armour') were
placed along the foot of the cliff, and built out into the sea to form a groyne. The plan was to create an obstruction
which would lead to the deposition of a beach - which would absorb the power of the waves and protect the cliff. To
the left of this photograph we see the success of the groyne in developing the beach.

19. CLIFFS AT MAPPLETON
The cliffs at Mappleton are being eroded at several metres per year. This fence was only a few months old by the time
the sea had undermined its posts. The soft glacial deposits can be undercut by even the smallest waves.

20. Cliffs at Great Cowden
The success of the cliff defence at Mappleton was at the expense of the cliffs at Great Cowden, 3km to the
south. Deprived of the sediment source, the beach here has been eroded by long-shore drift. As a result, the cliff is
eroded by almost every high tide and the cliff-line has receded rapidly. It seems that the cost of protecting the cliffs
in one area is to accelerate erosion in another.

21. The local authorities are endeavouring to prevent the effects
of erosion.
Hard defences in the form of a concrete seawall and timber
groynes have given some protection.
It has been suggested that a large underwater reef made of
tyres could be built off the Holderness coast to mitigate this
erosion but it would be costly to build.

22. Other defences include sea walls, groynes, and gabions but
business people say that if the erosion is not stopped then
there will be millions of pounds of damage.
One or more such groynes has had a detrimental effect further
along the coast, in some areas resulting in erosion of up to
twenty metres per year initially, though over the long term
erosion rates have been seen to revert to their original yearly
average of closer to two metres a year.