Describe the process of cliff (scarp) retreat and the landforms that result from it.

Cliff retreat, also called scarp retreat, is a natural process of erosion in which a cliff, typically found along seacoasts or other bodies of water, gradually erodes and recedes inland. This process usually occurs when waves or other natural forces undermine the base of the cliff, causing the overlying materials to weaken and collapse.

The main cause of cliff retreat is coastal erosion, which results from several mechanisms: 1. Hydraulic action: Waves crash against the base of the cliff, compressing the trapped air in the cracks of rocks, causing additional pressure and ultimately causing the rocks to break apart. 2. Abrasion: Waves transport sand, pebbles, and other materials that hit the cliffs, causing them to erode over time in a process similar to sandpapering. 3. Attrition: Rocks and pebbles carried by waves collide with each other, breaking into smaller fragments and becoming rounder in shape, which contributes to abrasion. 4. Solution: Minerals in the rocks of the cliff dissolve in seawater, which weakens the cliff structure, and may eventually lead to collapse.

The process of cliff retreat consists of several stages: 1. Wave action erodes the base of the cliff through mechanisms mentioned in step 2. 2. Over time, this causes the cliff to weaken and a notch to form at the base where the erosion is strongest. 3. The weight of the overlying cliff material becomes unsupported, causing the cliff's structure to weaken further. 4. Eventually, the unsupported weight causes the cliff to collapse and break away. 5. The eroded materials are carried away from the shore by currents and tides, resulting in the cliff line receding inland.

Several landforms result from the process of cliff retreat: 1. Wave-cut platforms: These flat, horizontal surfaces develop at the base of the cliff as the waves erode and retreat the shoreline. These platforms gradually get wider as the cliff retreats inland. 2. Caves, arches, and stacks: Persistent erosion at the base of the cliff may cause a cave to form. If a cave on either side of a headland erodes through the headland, it may create a natural arch. When an arch collapses, it can leave an isolated pillar of rock called a stack. 3. Bays and headlands: Cliff retreat also causes the formation of bays and headlands. Bays are formed when a softer, more erodible rock is eroded at a quicker pace than the harder, more resistant rock surrounding it. Headlands are created as these harder rocks remain intact and jut out to sea.

Cliff retreat is a natural process in which the shoreline erodes and recedes due to the mechanisms of coastal erosion, creating various landforms such as wave-cut platforms, caves, arches, stacks, bays, and headlands. The process can be summarized in five steps: 1. Waves erode the base of the cliff 2. A notch forms at the base of the cliff 3. The cliff weakens and collapses under its unsupported weight 4. Eroded materials are carried away from the shore 5. New landforms, such as wave-cut platforms, caves, arches, stacks, bays, and headlands, are formed as a result of the erosion process.