Landform Case Study: Holderness Coast

Question 1

The Holderness coast is a well-know stretch of coastline in

Answer 1

eastern England

Question 2

The Holderness coast forms a subcell in sediment cell

Answer 2

2

Question 3

Holderness coast essentially comprises 3 distinct coastal units:

Answer 3

• Flamborough Head in the North- a chalk promontory that exhibits many typical landforms associated with coastal erosion (headland)
• Bridlington Bay to Spurn head- an extensive zone of erosion and sediment transfer characterised by a very rapid rate of cliff retreat
• Spurn Head- a classic spit formed at the estuary of the river Humber

Question 4

Within the subcell (Holderness coast), the main input is

Answer 4

• erosion of the weak and unconsolidated till cliffs
• some of the other sediment is washed offshore to form an output from the system while the slightly coarser material is moved southwards as a transfer involving LSD
• some sediment is deposited to form Spurn Head, while a significant amount continues south towards East Anglia

Question 5

Explain the location and formation of Flamborough Head

Answer 5

• jutting into the North Sea from the east coast of England, Flamborough Head is one of the most recognisable features on a map of the uk
• the main reason for the formation of the headland is because it is made of chalk- a resistant sedimentary rock
• vertical cracks run through the chalk (joints)
• in some places whole sections of chalk which are readily exploited by the processes of weathering and erosion to form narrow clefts in the coastline- one major faultline has been exploited to form Selwick’s Bay

Question 6

Discuss rates of erosion from Bridlington Bay to Spurn Head

Answer 6

• the stretch of coast has retreated by up to 5km since Roman times, which accounts for the loss of several settlements and ports by erosion
• with rates of erosion in excess of 1m per year, the Holderness coast has one of the most rapid rates of erosion in Europe

Question 7

Although erosion along the coastline does not generate threats, it does generate

Answer 7

• a vast amount of sediment that feeds the sediment cell
• much of the finer sediment is carried offshore but a great deal of coarse sediment is transferred by LSD to the south, building up beaches and reducing erosion (NEGATIVE FEEDBACK FOR SYSTEM)
• Spurn Head itself is nourished by this sediment transfer and it has an important role in protecting the towns and land bordering the River Humber from the effect of storm waves and flooding
• there is evidence that some sediment from the Holderness ends up on the coast of the Netherlands, helping to protect it from flooding
  = this is massive planning conundrum as- should erosion be hanged to protect a few houses and agricultural land or should it be allowed to continue, as it is a vital source sediment?

Question 8

Several factors account for the rapid rate of erosion on the Holderness coast:

Answer 8

• long fetch and powerful waves from the north-east
• weak and unconsolidated till cliffs
• extensive mass movement, especially slumping caused by undercutting and saturation of clay within the cliffs
• narrow beach making cliffs vulnerable to wave attack and undercutting
• lack of coastal defences

Question 9

Explain the formation of Spurn point

Answer 9

• Spurn head represents a temporary sediment store/sink. Much of the material that forms the spot is derived from the Holderness coast and transferred south by LSD
• on reaching the River Humber estuary, the deposited sediment grows out to form a narrow finger of new land (spit)- its curved tip resulting primarily from direct wave action
• Spurn Head is extremely narrow for much of its length and has frequently been breached and destroyed by major storms
• sea is actively eroding and undercutting the base of the cliffs leading to frequent rockfalls- over time the cliff retreats forming wave-cut platforms and stacks
• when waves approach the coastline they are refracted by the shape of the coast = waves therefore have low energy in the bay = deposited beach
• the more exposed headlands bear the full force of the incoming waves; this is why they are often characterised by steep cliffs and other features of coastal erosion

Question 10

When did Spurn Head first form?

Answer 10

first formed 8000 years ago at the end of the last glacial period and evidence suggests that the feature has gone through a number of cycles of growth and decline, lasting on average 250 years

Question 11

Following a massive breach before 1900s, groynes and revetments were erected to stabilise

Answer 11

The spit

Question 12

What happened after 1849 when groynes and revetments were erected?

Answer 12

• in subsequent years, when military forts were established at Spurn point, the Royal Engineering took over the task of maintaining coastal defences
• in 1950s, the military left and in 1960 the spit was bought by Yorkshire Naturalists’ Trust unable to afford the maintenance costs of the spot- trust had to allow some of the sea defences to fall into despair
• when the largest tidal surge in 60 years hit Spurn point in 2013, the defences could not cope= buildings were destroyed and the access road swept away

Question 13

What are factors that affect Holderness’ (coastal) system?

Answer 13

• geology
• wind
• hard engineering/lack of defences in areas

Question 14

How does geology affect the coastal system?

Answer 14

• important factor affecting the processes and landforms here e.g. Flamborough head comprised of chalk
• the eastern edge of the chalk outcrop formed the preglacial coastline and that the great sweep of the present day coastal zone is the result of sediment carried and dumped by ice sheets originating from Scandinavian
• as sea levels rose at the end of the last glacial period, the North Sea took shape and started to erode the thick till deposits to form the present-day cliffs

Question 15

How does wind affect the coastal system?

Answer 15

• when the wind is blowing from the north-east (direction of the greatest fetch), it can drive powerful waves towards the Holderness coast
• occasionally, areas of extremely low pressure move down the North Sea, funnelling water and creating storm surges several metres high
• these low-frequency, high-magnitude events can lead to significant erosion and flooding
• in 1953 more than 300 people lost their lives along the east coast of England during such an event
• as a result of these powerful north-east waves, LSD operates from north to south along the Holderness coast

Question 16

How does hard engineering affect the coastal system?

Answer 16

• in response to rapid rate of erosion and the threat of settlements and infrastructure, parts of the coastline have been protected with hard-engineering
• structures such as sea walls, rock armour and groynes have been implemented
• although these interventions have helped protect specific localities such as Mappleton, they have deprived areas further south of sediment, thereby exacerbating coastal erosion
• the lack of beach renders cliffs much vulnerable to undercutting and collapse
• in contrast, no intervention from Bridlington Bay to Spurn Head as Spurn head formed from southwards LSD