Marine Patterns and Processes Flashcards
Name 2 wave types and the characteristics of each
-Destructive waves: Powerful swash, weak backwash
-Constructive waves: Weak swash, Strong backwash
What are the types of marine erosion?
-Hydraulic action
-Abrasion
-Erosion by compressed air
Explain erosion by compressed air
-Air is forced into the strata of the soft rock in the headland by waves
-When the wave retreats, the air escapes quickly.
-The rocks in the headland contract and shatter
What is the process of marine deposition/transportation?
Longshore drift
Explain longshore drift
-Constructive waves hit the beach at an angle
-Waves then retreat at a straight angle
-Sediment is pushed along the beach
What are the features of marine erosion?
-Cave
-Sea Arch
-Sea stack
-Sea stump
What are the features of marine deposition?
-Sand spit
-Sand bar
-Tombolo
-Beach
How does human interaction affect marine erosion?
It slows down the processes of erosion
Name 3 human interactions that slow down marine erosion
-Sea wall
-Rock armour
-Gabions
Name a human interaction that slows down marine transportation
Groynes
What is a sea wall?
-Stone wall built to stop destructive waves
e.g. Bray, Co. Wicklow
What is rock armour?
-Giant boulders placed in front of breaking waves to weaken the waves energy
e.g. Strandhill, Co. Sligo
What is a gabion?
-Steel metal cages full of rocks that break the force of the wave
e.g. Lahinch, Co. Clare
What is a groyne?
-Concrete or wooden walls that are built perpendicular to the coast, in order to trap sediment carried by the waves
e.g. Rosslare, Co. Wexford
How is a sand spit formed?
Constructive waves push sediment lower down the beach by process of longshore drift
This causes a sand spit to form at the end of the beach
