Erosion by wind, ice and thermal

• Waves and wind move sand and small bits of the Earth.
• Wind forms sand dunes, changing their shape and blowing soil off farmland.
• Wind-carried sand and soil slowly change the shape of rocks.

Erosion by Ice

• Ice, mainly in glaciers, erodes the earth, creating landforms.
• Glaciers move downhill in cold areas and mountaintops.
• They transport everything, from tiny grains to giant boulders.
• Rocks carried by glaciers scrape the ground, eroding both the ground and rocks.
• Glaciers grind rocks and scrape away soil.

Thermal Erosion

• Thermal erosion affects permafrost along rivers or coastlines.
• Warm temperatures cause ice-rich permafrost to break off coastlines in huge chunks.
• Topsoil and vegetation are also carried with the ice.
• These eroded "floating islands" can disintegrate in the ocean or crash into other land.
• This disintegration assists the growth of life in different landscapes.

Coastlines

• A coastline marks where land meets sea (oceans).
• Coastlines have beaches, cliffs, capes, caves, bays, and estuaries.

Coastal Features

• Beach: An accumulation of sand or pebbles along the coast.
• Cliff: A steep rock face shaped by the sea.
• Cave: Natural underground cavity formed by water slowly dissolving and eroding rock.
• Dune: Accumulation of sand shaped by the wind.
• Headland: Tapering strip of land jutting into the sea.
• Lagoon: Shallow expanse of seawater separated from the sea by a sand ridge or barrier island.
• Natural Arch: Arch hollowed out of a headland by the sea.
• River Estuary: Formed by the mouth of a river that is influenced by the tides; the indentation in the coastline varies in width and depth.
• Rocky Islet: Small island made of rock.
• Skerry: A small rocky island.
• Spit: Elongated ridge of sand or pebbles extending into the water.
• Stack: Needle-shaped column resulting from the collapse of an arch.
• Tombolo: Ridge of sand that joins an island to the shoreline.

Coastlines

• The coast is the land along a sea; the boundary between land and water is the coastline.
• Waves, tides, and currents shape coastlines.
• Eroding water wears away at the land.
• Little parts of the sea like shells, sand dollars, seaweeds, and hermit crabs remain.
• Hard materials like granite make coasts stable for centuries.
• Tides (ocean rise and fall) deposit sediment on the coast.
• Large tidal ranges are where waves deposit shells and hermit crabs further inland.
• Small tidal ranges see smaller waves that place material closer to shore.
• High energy in larger waves move more sediment.
• Larger beaches allow waves to spread their energy and deposits.
• Smaller, narrow beaches concentrate wave energy, making them look tattered and weathered; sandy beaches are washed away, and rocky coastlines are cracked by strong waves.

Changing Coastlines

• Coasts indicate natural events like weather and changing sea levels.
• Coasts are the first to flood during storms.
• Some coasts have coastal plains (flat, low-lying land visible when sea levels drop).
• Coasts can be rough due to pollution, oil spills, and garbage.
• Pollution affects their appearance.
• Pollution damages marine life.