Primary and Secondary Coasts

• A coast is the land or area next to the ocean (seashore)
• Marine coasts, also called the seashore, are dynamic regions that constantly change
• Marine coasts are classified into primary and secondary coasts

Primary Coasts

• Formed by land-based processes
• Can include: erosion, sediment deposition, tectonic activity (earthquakes, volcanoes), and sea level changes
• Delta: deposit of sand and soil at a river's mouth
• Drowned River Valley: eroded by water or glaciers
• Fault Coast: created by tectonic movement in the Earth's crust
• Lava Coast: formed by volcanic eruptions

Secondary Coasts

• Formed by ocean-based processes
• Include wave erosion, water chemistry, and marine life
• Reef: ridge of rock, sand, or coral rising toward the water's surface (e.g., Great Barrier Reef)
• Mangrove Swamp: tropical evergreens growing along tidal shores with above-ground roots
• Salt Marsh: marshy grassland often flooded by seawater
• Sea Stacks: durable coastal formations left after erosion removes loose sediment

Primary Coast Features

• Shaped by land-driven processes
• Include: volcanic activity, earthquake activity, land-driven processes and sea level rise
• Other features: glacier erosion, drowned river mouths, deltas, estuaries, and mangrove swamps

Secondary Coast Features

• Shaped by ocean-driven processes
• Include: sea stacks, barrier islands, kelp forests and sand bars
• Other features: coral reefs, sand spits, ocean-driven processes, salt marshes, and wave erosion

Landform Processes

• Coastal deposition occurs when material being transported is dropped by constructive waves
• Coastal erosion is the process by which coastal waters wear or tear down soil, rocks, and sand along the coast

Rocky Coast Characteristics

• High energy and high erosion
• All types of rocks, faults, folds, and igneous intrusions are present
• They have a resistant bedrock profile, high-energy winds and waves

Rocky Coast Landforms

• Fjords: Glaciers carved deep valleys that were eventually filled with seawater
• Headlands: small beaches that are isolated with little to no exchange of sediment (capes)
• Sea Caves: large, hollow chambers caused by sea erosion from waves
• Sea Arches: natural bridge or rock formation caused when waves wear away the bottom of a rock
• Sea Cliffs: steep faces of rock and soil formed by destructive waves
• Tidewater Glacier: glacier that descends into the sea and typically forms icebergs

Sandy Shore Landforms

• Characterized by low energy and high deposition
• They feature highly complex landforms that experience constant change due to wave action and sediment transport
• Sandy shores are obstacles to wave activity

More Sandy Shore Landforms

• Barrier Island: constantly changing deposit of sand that forms parallel to the coast
• Barrier Spit: narrow strips of sandy landforms connected to the mainland but stretching out into the sea
• Beach: narrow strip of land separating a body of water from inland areas, made up of tiny rocks and minerals
• Dune: ridge or hill of loose sand that acts as a buffer from the effects of storm waves
• Tombolo: piece of land or sand that connects a previous island to the mainland

Summer Coastal Landforms

• Well-developed berms
• Higher water maintained and gently sloped
• Typically calmer waves

Winter Coastal Landforms

• May or may not have a berm
• Lower water that is steep-sloped
• Characterized by intense waves

Summer vs. Winter Causes

• There is potentially less erosion and calmer waters in Summer than in Winter
• Conversely, there is potentially more erosion and intense waters in Winter than in Summer
• There is more deposition and lower energy in the Summer in comparison to Winter
• There is less deposition and higher energy in the winter compared to Summer

Seasons

• Summers typically have less intense storms and therefore smaller waves
• Winters typically have more intense storms and therefore larger waves

Explore marine coasts and their classifications. Primary coasts are formed by land-based processes like erosion, sediment deposition, and tectonic activity. Secondary coasts are shaped by ocean-based processes, including wave erosion and marine life.