Coastal Landforms Created by Sea Waves: Erosion & Deposition Features

Wave action sculpts coastlines through erosion (wearing away) and deposition (building up). Here are the key features formed:

Erosional Features (Rock Removal)

• Headlands — resistant rock promontories left after softer rock erodes.
• Sea Cliffs — steep rock faces from undercutting at base; retreat inland over time.
• Wave-Cut Platforms — flat, submerged rock benches at cliff base; exposed at low tide.
• Sea Caves — hollows carved by hydraulic action/compression in fractures.
• Sea Arches — caves cut through headlands; roof may collapse.
• Sea Stacks — isolated pillars after arch collapse (e.g., Old Man of Hoy).
• Blowholes — vertical shafts where waves force water/air upward.

Depositional Features (Sediment Buildup)

• Beaches — sand/pebble accumulations in sheltered bays; dynamic, seasonal.
• Spits — longshore drift deposits extending across bay mouths (e.g., Spurn Head).
• Bars — submerged or emergent ridges across estuaries/bays.
• Tombolos — spits connecting island to mainland (e.g., Chesil Beach).
• Barrier Islands — long, narrow sand islands parallel to shore (e.g., Outer Banks).
• Dunes — wind-blown sand behind beaches; stabilized by vegetation.

Bays & Headlands: The Classic Pair

Discordant coastlines (alternating hard/soft rock) erode into headlands (hard) and bays (soft). Over time, headlands take the brunt of wave energy, while bays accumulate sediment — a self-reinforcing cycle.

These features are dynamic — storms, sea-level rise, and human intervention constantly reshape them.