What is meant by an erosional coast? What are the expected features of such a coast?

Coastal geography is the study of the constantly changing region where land meets the sea. This includes understanding the physical features such as beaches, cliffs, and dunes, as well as the dynamic processes that shape these features over time. Erosional coasts, a key focus of coastal geography, are areas where wave and current action predominates, leading to the gradual wearing away of the shoreline.

It's important for students to visualize these areas not as static scenes but as lively stages of natural drama where landforms are actors subject to the whims of the sea's erosive forces. Coastal geography also takes into account human activities that affect coastal landscapes, like development or protective measures such as sea walls. Understanding how natural and human-induced activities intertwine can extend a student's comprehension beyond textbook definitions.

Marine erosion processes are the set of natural mechanisms through which coastal landscapes are worn down and reshaped. These processes include:

• Hydraulic action - When waves crash against the shore, water is forced into cracks, causing rock fragments to break off.
• Abrasion - As waves retreat, they drag sediment and pebbles across the rock face, functioning like sandpaper.
• Attrition - Rock fragments carried by the sea knock against each other, breaking into smaller, smoother pieces.
• Wave-cutting - Waves cutting at the base of cliffs or landforms can create undercuts, leading to instability and collapse.

To reinforce these concepts, students might find it helpful to compare these natural processes to familiar tasks such as using a hammer to chip away at a surface (hydraulic action), sanding wood (abrasion), tumbling rocks to polish them (attrition), or undercutting a cake to remove a slice without toppling the rest (wave-cutting).

Erosional coastal features are dramatic and striking landforms created by the relentless work of marine erosion processes. Some distinctive features include:

Cliffs and Steep Slopes

Formed by the continued erosion of land by the sea, cliffs are steep rock faces that can be found along many erosional coasts. Residential development or public access at the top of cliffs is often limited due to the potential instability of these features.

Wave-cut Platforms

A flat area that remains after a cliff has retreated is known as a wave-cut platform. This shelf of rock is usually visible at low tide, extending out from the base of the cliff.

Sea Arches and Stacks

These features often start as caves carved into headlands until they become arches. Over time, the ceilings of these arches collapse due to their weight and the continuous battering by waves, leaving pillars of rock known as sea stacks.

Headlands and Bays

Headlands are protrusions of the coast into the sea, often composed of harder rock that resists erosion and forms a protective boundary for softer rock, resulting in recessed areas called bays.

By recognizing these features, not just as scenic elements but as signs of the powerful forces shaping our planet, students can deepen their understanding of Earth's dynamic nature.