The Sea Flashcards
What does the size of a wave depend on
The wind and the fetch
Explain swash
The frothy water that rushes onto the shore after a wave breaks
Explain backwash
The water that runs back out to sea from the shore
Give the characteristics of a destructive wave
They have a lot of energy and have a strong backwash and weak swash. They erode the coastline
Give the characteristics of a constructive wave
They have a strong swash and a weak back wash. It deposits material and builds up the coastline.
Explain hydraulic action
The force of the water hitting the coastline causing it to erode
Explain air compression
The waves trap air in the cracks of rocks and as the waves retreat the trapped air expands and can crack the rock.
Explain abrasion
Eosin caused by the small rocks carried by the sea hitting against the coastline.
Explain attrition
Erosion caused by small rocks hitting each other and breaking themselves into smaller pieces.
Explain how a cliff is formed
The waves cut a notch in the rock creating an overhang. The notch then gets deeper and the overhang collapses leaving a wave cut platform. This continues and the coastline retreats inland.
Ex. Cliffs of moher. Co. Clare.
Explain how a bays and headlands are formed
A bay is a wide opening in the coastline and a headland is a pice of land jutting out to sea.
Soft rock erodes quickly and hard rock erodes slowly. A bay is formed when soft rock is eroded in between two pieces of hard rock and the headlands are the hard rock.,
Give and example of a bay and headland
Dublin bay and howth head
What is a sea cave and how is it formed
This is a tunnel at the base of a cliff but it doesn’t cut right through the cliff/headland.
The waves erode a weak point into the rock called a cave
Explain what and how a sea arch is formed
A sea arch is a passage that runs completely through a headland. T his can happen when a cave is eroded further or two caves meet in the middle to form a complete passage through a headland called a sea arch
Explain what and how a sea stack is formed
A sea stack is a pillar of rock standing I. The water near the coast.
When sea arches erode further a sea stack is formed. The roof of the arch collapse forming a pillar of rock isolated from the land.