GEOG 120 Lecture Notes - Lecture 16: Longshore Drift, Fot, Asteroid Family
Document Summary
Coastal environments- wind generated waves and landforms. Arid environments- aeolian processes and landforms. Particles in waves follow an orbital motion that diminishes with depth. See wave diagram in text for wave height, wave length, crests and troughs. These characteristics and their speed of motion are effects of the wind motion. See wave transition with water depth diagram for water and seabed interactions. Surf zone- zone where shallow water waves tend to break, collapse, curl. Demonstrates breakers, swash and backwash flows. Swash- lateral up shore flow. Oblique wave approach sets up sediment transport along the shore see textbook diagram for hopscotch transport of material. Beach drift, longshore drift, littoral (shoreline) drift. Deposits in low energy locations. Depositional features: spits, bars and tombolos. Retrogradation a coastline that is being eaten back in a landward direction. Wave energy high, sediment supply is low. Features include: sea cliffs, marine arches, stacks, wave cut notches/undercutting, abrasion platforms. Progradation- builds out in seaward direction.
