EQ2 4.3 B Flashcards
What three factors affect wave energy?
Wind speed
Wind duration
The distance over water that the wind blows in a single direction.
Characteristics of a destructive wave?
Created from powerful waves and when the wind has been blowing for a while. They erode the coast. They have a stronger backwash then swash.
Compare freeze thaw, biological and chemical weathering
Freeze thaw is when water melts and freezes in the cracks of rocks and then expands the cracks. Biological is when roots get into rocks and break down the structure and put pressure on the rocks and larger cracks are formed. Chemical is when the carbonic acid reacts with the rocks and it dissolves and washes away.
Define abrasion
When waves break, the sediment (rock) is thrown and rubbed against the cliff.
Define attrition
Waves cause rocks and pebbles to smash into each other and become smaller and more rounded.
Define hydraulic action
When a wave breaks against a cliff, air and water is forced into cracks in the cliffs and increases pressure, causing rocks to break off.
Define mass movement
Its when the surface material moves because of gravity. For example Landslides.
Gove the process of rotational slumping
- Sand is permeable and allows water to pass through it.
- rain falls and accumulates at the boundary between sand and clay which lubricates the boundary.
- clay is impermeable and prevents the water moving through it.
- the sand becomes saturated and will dramatically slump in a rotational shape.
Give the process of rock slides
- the rock falls in a straight diagonal line down the cliff. The rock falling often stays in one piece.
- joints or bedding planes are aligned diagonally to the sea.
- erosion at the base, or weathering at the top of the cliff weakens the cliff.
- the cliff becomes unsupported and sometimes lubricated by rain.
What is sub aerial process?
It is weathering that decays and disintegrates the rock. Chemical and biological are types of weathering.
