Caves, arches and stacks - Gcse Flashcards
What are waves particularly good at?
Exploiting any weakness in a rock such as a joint.
What can any vertical line of weakness be turned into?
From hydraulic action and abrasion they can turn into caves.
But it has to be hard or resistant otherwise it will collapse.
What happens when a wave has formed?
When a wave breaks it blocks off the face of the cave and traps air within it.
What happens when air becomes trapped inside the cave?
Air becomes compressed inside the cave which increases the pressure on the roof, back and sides.
What happens when the cave is open at both sides?
The cave then becomes a natural arch.
What happens to the arch?
The base it attacked by waves putting more and more pressure on the top of the arch.
After more erosion the arch will eventually become a stack.
What is a stack?
Its a piece of rock isolated from the coastline.
