Jurassic Coast Case Study

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Important locations on Jurassic Coast

* Chesil Beach - tombolo
* The Fleet Lagoon (behind Chesil Beach)
* Chalk headland - Old Harry stack
* Sandbanks spit

How does GEOLOGY affect geomorphic processes here?

* Made of bands of **harder** (chalk + limestone) **and softer rock** (clay) → headlands and bays
* Has both **concordant** + **discordant** coastlines

Temperature’s effects

* **Warm, dry** summers
* **Freeze-thaw rare** due to mild winters

Wind’s effects

* South west **prevailing winds** can bring **storms** from Atlantic
* High energy **destructive waves** can increase erosion - eroding base of cliffs
* Unstable cliffs → mass movement

Rainfall’s effects

* **Relatively low annual rain (but heavy rain in winter)**
* Soils can **saturate** in winter - slumping of cliffs
* **Chemical weathering** of chalk (**carbonation)**

**Quarrying** impacts

* Limestone (building material) quarried on Isle of Portland
* Quarries **expose** large areas of rock, making them vulnerable to **chemical erosion**

**Tourism** impacts

* Major tourist attraction
* Coastal footpaths **eroded by walkers**
* This **exposes soil and rock** to **weathering and erosion** by wind and rain

Swanage coastal management

* 1.8km coastal defence works - mainly **stone sea walls** and **timber groynes**
* 90,000m^3 **sand deposited →** dissipate wave energy

Positives of defences

Lots of **hard + soft defences →** __holistic__

Negatives of defences

* Beach nourishment needs **recharging**
* Groynes **starved** the north region of **sediment** → narrower beach, less __dissipation of wave energy__