9- Landforms And Landscapes Flashcards
Difference between tides and current
Tides- created due to gravitational pull of moon and change every 6 hours
Currents- movement of water in a particular direction, driven by wind and differences in temperature/ water density
What happens to waves when they reach shallower water
They break
Crest of waves move forward faster than trough as friction happens with trough and sediment on shore so eventually waves plunges
What is hydraulic action
Pressure of sea water forces open cracks in cliff
What is corrosion
Seawater and salt spray from waves reacts with rock minerals dissolving them
Minerals carried away in solution
4 types of deposition all landforms
Tombolos
Cuspate foreland
Bars
Spits
How is a tombolo formed
Bar liking to offshore island
Formed by:
Wave refraction around island creates area of calm water which encourages devotion between island and coast
How is a spit formed
Curves into shallower water due to:
Effects of wave refraction
Secondary winds approaching in opposite direction to prevailing winds
How is a cuspate foreland formed
Growth of 2 spits from opposing longshoreman drift directions, land eventually forms behind
2 factors affecting stability of depotional landforms
Vegetation- plant succession stabilises by binding sediment and encouraging deposition
Human interaction- evacuation of sand and silt for grounds (negative affect)
What is a sediment cell?
Self contained stretches of coast consisting of sources, transfers and sinks
How are salt marshes formed?
Flocculation of sediment in the shallow water of estuaries
Describe effects of sub aerial processes on coastal landscape
Increase recession when combined with marine processes
Accumulation of weathered material act as barrier to marine erosion- barrier to recession
