lecture 7 Flashcards
What is the difference between “coast,” “coastline,” “shore,” and “shoreline”?
Coast is the zone inland to where ocean-made features are found. Coastline is the boundary between coast and shore. Shore is the zone between low tide and storm wave base depth. Shoreline is the intersection of water and shore
What materials are beaches usually composed of?
Beaches are composed of local materials like sand, silt, clay (mud), shells, and sometimes larger materials like grits, granules, pebbles, cobbles, boulders (collectively: gravel), and rocks (igneous, sedimentary, metamorphic).
What distinguishes erosional shores from depositional shores?
Erosional shores are dominated by processes that remove more material than they deposit. Depositional shores are dominated by processes that deposit more material than they remove.
How is beach material moved perpendicular and parallel to the shoreline?
Perpendicular to the shoreline, material is moved by rivers, waves, tides, rip tides, and local erosion. Parallel to the shoreline, material is moved by upcoast and downcoast processes, mainly through longshore drift
What are rip currents?
Rip currents are strong, narrow, fast-flowing surface currents flowing seaward from the shore, nearly perpendicular to it, which can travel hundreds of meters from shore before breaking up.
How do sea levels change at shores?
Sea levels change due to plate tectonics, glaciation, and lithospheric adjustments. This can result in emerging shorelines, marine terraces, submerging shorelines, and drowned beaches.
What defines the extent of coastal water?
The shape of the continental shelf defines the extent of coastal water, exhibiting unique properties such as variations in salinity and temperature.
What are the different types of deltas?
Types of deltas include sediment-dominated deltas (e.g., Mississippi River delta), wave-dominated deltas (e.g., Nile River delta), and tide-dominated deltas (e.g., Chesapeake Bay).
What are some common coastal environments
Common coastal environments include deltas, estuaries, lagoons, and wetlands. Each has distinct features and plays a crucial role in the coastal ecosystem
How do human activities impact coasts?
Humans build structures like groins, jetties, breakwaters, and seawalls to ‘protect’ beaches from erosion, but these interfere with natural shoreline processes and can have negative impacts on the coast.
