Holderness Coast Yorkshire

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The Holderness coast lies next to the North Sea, stretching between the Flamborough Head in the North and Spurn Head in the South. It is the fastest eroding coastline in Europe. Most of the coastline consists of cliffs until it meets the Humber estuary at Spurn Point. The area is mainly made up of soft boulder clay and is therefore easily eroded by waves. 1.5m tonnes is carried away by the sea each year. 4km has been lost since Romanian times.

Erosion is a problem because of;

Geology

Fetch

Longshore Drift

Geology:

The Holderness coast has two rock types; chalk and boulder clay. The chalk at Flamborough Head is fairly resistant and produces features such as cliffs, caves, arches and stacks. The rest of the coast is boulder clay which has little resistance to erosion, especially when wet. Boulder clay produces shallow sloping cliffs which erode by about 2metres a year

Fetch:

Holderness is exposed to waves that have a small fetch of 500-800km. The size of the waves attacking Holderness coast is increased by four other factors;

Currents/swell - the Atlantic fetch is 5000km or more and its currents add energy to waves in the North Sea. Therefore there are often powerful destructive waves along this coastline eroding the cliffs

Low pressure weather systems passing over the North Sea are often intense and locally produce strong winds and waves

Small enclosed seas like the North Sea often generate huge waves during storms. Waves move within the sea but can't disperse their energy

The sea floor is deep along the Holderness coast, therefore the waves reach the cliff without being weakened first

Longshore Drift:

Boulder clay erodes to produce mainly clay particles which are easily transported out to sea rather than accumulating close to the cliffs as beach sand. The sand that is produced is taken southwards by longshore drift, leaving the cliffs unprotected from wave attacks.

Protecting the Holderness Coast:

Hard engineering techniques;

Groynes

Revetments

Sea walls

Soft engineering techniques;

Beach nourishment

Coastal zoning - managed retreat