Erosional Coastal Landforms
Sea Cliff
The most widespread landforms of erosional coasts are sea cliffs. These very steep to vertical bedrock cliffs range from only a few metres high to hundreds of metres above sea level. Sea cliffs are created by waves crashing directly on a steeply inclined slope. Hydraulic action, abrasion, and chemical solution all work to cut a notch at the high water level near the base of the cliff. Constant undercutting and erosion causes the cliffs to retreat landward.
Wave-cut Platform
A wave-cut platform, shore platform, coastal bench, or wave-cut cliff is the narrow flat area often found at the base of a sea cliff or along the shoreline of a lake, bay, or sea. A wave-cut platform is formed when the sea attacks the base of the cliff between the high and low water mark. A dent in the cliff is then formed, usually at the level of high tide. As the dent increases in size, the cliff becomes unstable and collapses, leading to the retreat of the cliff face. The backwash carries away the eroded material, leaving a wave-cut platform. The process repeats and the cliff continues to retreat.
Caves, arches, stacks, and stumps
Headlands can be vulnerable to erosion because they stand out from the rest of the coast. Over time, other features may develop on a headland, including caves, arches, stacks, and stumps.
Karst
A karst landscape is formed when easily dissolvable bedrock (the rock below the surface of the land) such as limestone is worn away slightly acidic water, from an underground source or a source on the Earth's surface. These flows of water form unique features such as caves, stalactites, springs and sinkholes. Karst landscapes are extremely unstable areas of land. Sinkholes are formed when rock beneath the Earth's surface has eroded away and sections of land on the surface collapse.
