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The Holderness Coastline Case study - Coggle Diagram
The Holderness Coastline Case study
Coastal Management
The SMP aims to protect the key settlements of Bridlington, Hornsea and Withernsea along with the important coastal roads such as B1242 at Mappleton and gas pipeline landfall and gas processing facility at Easington.
Hornsea has an old revetment at the south end of the beach,
There are all protected using Hold the line: Brislington, Withernsea and Hornsea have a sea wall, groynes and rip rap.
Mappleton has approx 50 propertie but also te vital but also the vital B!242 access road. In 1991 a decision was made to spend £2 million on rack armour and two rock groynes.
Soft engineering methods of cliff regrading, stabilisation with vegetation and cliff drainage to prevent saturation and reduce the chance of rotational slumping have also been used at Mappleton.
To protect the gas terminal at easington, rock armour has been used and cliff angle has been reduced.
Flamborough Head
Formed from chalk- resistant sedimentary rock
The strata in the rock is roughly horizontal, the lines between each layer is referred to as bedding planes.
Vertical cracks (joints) form lines of weakness which are attacked by marine erosion processes creating a number of erosional landforms.
Faults in the chalk have resulted in the displacement e sections of chalk though weathering and erosion, forming small bays.
Waves are refracted as they approach the headland resulting in greater erosion of the exposed headland and deposition of a beach in the bay where there is low energy.
The North Sea
It has been formed due to the eustatic change during the Holocene period.
During the last ice age, sea levels were much lower as more of the Earth's store of water was locked up in the cryosphere.
Temperatures have warmed over the last 10, 000 years due to natural change, much of this ice has melted causing rising sea levels,
In the last 100 years, eustatic change has been increased as a result of anthropogenic activity leading to the enhanced greenhouse effect and thermal expansion.
Geology
Boulder clays which was left behind when the ice sheet covering the north of the Uk, the area that now forms the North Sea and Scandinavia melted at the end of the last ice age around 18,000 years ago.
It is bounded by the chalk headland of Flamborough Head to the north. The chalk dips below the boulder clay just north of Bridlington.
Erosion
The Holderness Coast is often quoted as being Europe's fastest eroding coastline, although rates do vary.
Cliff have retreated between 3 and 5 km since Roman times. Rates of erosion are above 1 m per year and are up to 10 km per year in certain places.
The sediment eroded is an important input into the coastal system and is deposited as beaches (negative feedback) further south along the coasts as well as at Spurn Head.
The rate of erosion is mainly down to the weak and unconsolidated geology but is high due to: long fetch (3000 miles) from the NE, powerful destructive waves, rotational slumping and narrow beaches.
The North Sea suffers from areas of extremely low pressure which funnel water and create storm surges severa; metres high. Although rare, these events can lead to significant erosion. In 1953 more than 300 people lost their lives in such an event.
Spurn Head
A spit which formed across the Humber estuary and protects towns such as Hull from the effects of storm waves and flooding.
It provided a temporary sediment store and is made from material transported south from the Holderness coast via longshore drift, caused by the NE prevailing winds in the North Sea.
The spit first formed 8000 years ago at the stat of the Holocene inter-glacial period.
The spit is now owned by the Yorkshire Naturalists'' Trust who do not maintain defences. In 2013 the largest tidal surge in 60 years breached Spur Head, destroying buildings and access road.
Eustatic change and sea defences along the Holderness Coast may also be playing a part n increasing the vulnerability of Spurn Head.