Coastlines and Coastal Features

• A coastline marks the meeting point of land and sea.
• Coastlines feature beaches, cliffs, capes, caves, bays, and estuaries.
• Smaller landforms line up along a coast.

Coastal Features

• Natural arches are arches hollowed out of a headland by the sea.
• Rocky islets are small islands made of rock.
• A skerry is a rock tip that is just above the water's surface.
• Spits are elongated ridges of sand or pebbles that extend into the water.
• Cliffs are steep rock faces shaped by the sea.
• Sand islands are summits of sand deposits that are exposed near or far from a shoreline.
• Tombolos are ridges of sand that join an island to the shoreline.
• Beaches are accumulations of sand or pebbles along a coast.
• Dunes are accumulations of sand shaped by the wind.
• River estuaries are mouths of rivers influenced by tides and form indentations in the coastline.
• Caves are natural underground cavities that result from the slow dissolution and erosion of rock by water.
• Lagoons are shallow expanses of seawater that are separated from the sea by a ridge of sand or barrier island.
• Stacks are needle-shaped columns resulting from the collapse of an arch.
• Headlands are tapering strips of land that jut into the sea.

Weathering and Cliffs

• Freeze-thaw weathering can cause cliffs to break down.
• Solution (chemical weathering) breaks down calcium carbonate (limestone) cliffs.
• Plants can cause cliffs to break down.

Changing Coastlines

• The coast is the land along a sea, and the coastline is the boundary where land meets water.
• Waves, tides, and currents play a role in shaping coastlines.
• Waves erode the land and leave behind sediment.
• Coastal changes can take hundreds of years.
• The way coasts are formed depends on the material in the land and water.
• Harder material in the land is more resistant to erosion.
• Coastlines of granite are stable for centuries.
• Tides affect where sediment is deposited on the coast.
• Tidal range impacts the distance material is deposited inland.
• Larger waves carry more energy and can move more sediment.
• Coastlines with big beaches have more room for waves to spread their energy and deposits.
• Small, narrow beaches focus wave energy, giving them a tattered look.
• Sandy beaches are washed away, and rocky coastlines get cracked by strong waves.
• Coasts reveal information about weather and changing sea levels.
• Coasts are the first places to be flooded during storms.
• Coastal plains are flat, low-lying land that can become visible when sea levels decrease.
• Coasts are affected by pollution, oil spills, and garbage, damaging marine life.