Beaches Flashcards
What (2)
Accumulations of sediment
Represent temporary stores with sediment cell
Where + made of (2+)
Where = between highest point reached by storm waves and lowest tide lines
Made of = sand and shingle
Sand beaches what (2+)
Gentle slope because sand grains are small and easily compacted
Little water percolates through the sand = majority of water returns through backwash = smooths and flattens beach
Shingle beach what (2)
Steeper = larger sediment size
Backwash doesn’t really transport material back down beach = unlikely to be eroded
Top of beaches
Larger sediment = top of beach = high energy storm wave
Top of beach = storm berm?
Wider flatter area of sediment deposited by strong swash during spring tides
What do berms mark (2)
Below the storm berm = series of berms
Mark a series of high tide lines and formed by constructive waves
What are cusps (3+)
Form where waves break directly onto the beach
Both swash and backwash are strong
Form at a junction = sand on lower part of beach meets shingle on the upper
How is cusp shaped (2+)
Curved sides = channel incoming swash into the centre of the cusp
This creates a stronger backwash flowing out of centre of cusp = deepens the cusp
What are ripples (2)
Further down from cusps
Form = due to action of tides moving back and forth across the sand
What are ridges (3)
At the low water mark
Backwash deposits sediment that runs parallel to shore
Broken up by runnels = water runs through to return to sea
Types of beach alignment
Swash aligned
Drift aligned
What is swash aligned (3+)
Tend to firm in low energy environments = bay
Arriving waves are parallel to the shore
Wave refraction in bay = beach forms
What is a drift aligned beach (3++)
Waves approach coast at an angle
Longshore drift moves sediment along beach = often culminates in the form of spit if direction of coast chnages
Finer particles = carried further + become increasingly rounder as moved
