4.3-4.5 Flashcards
(28 cards)
What is the rock type like on a concordant coastline
The rock type is alternating bands of hard and soft rock parallel to the coast
What is the rock type like on a discordant coastline
An alternating band of soft and hard rocks that are at a right angle to the coast
What are joints
Joints are small usually vertical cracks found in many rocks
What are faults
Faults are large cracks caused by past tectonic movement
How do joints and faults effect erosion
Speeds it up as water can get in and freeze thaw and the rock becomes weaker
What is the difference between hard and soft rocks
hard rock doesn’t erode as easily
What are the characteristics of headlands and bays
Headlands pertrude forward while bays are eroded down and and form beeches
Describe the characteristics of a wave cut platform
At the end of a headland there are flat and wide platforms with rock pools and a very steep cliff going parallel to the platform
How is a wave cut platform formed
Hydraulic action and abrasion start to erode. A wave cut notch starts to form in the inter tidal zone. This causes the cliff to overhang and be unsupported .when the cliff collapses a rocky platform is left underneath. This process is then repeated
What are the characteristics of an arch stack and stump
At the end of a headlands with joints and faults erosion takes place eroding the base with hydraulic action and abrasion leading to a cave. The back of the cave will then be eroded leading to an arch. Then the roof collapses causing a stack to be formed which then is eroded at the base until it collapses leaving a stump. This process is repeated.
Where in the UK has the biggest waves
The SW coast has the biggest waves as the have lots of space to travel and have very strong winds in the same direction
Compare constructive and destructive waves
Destructive waves have high energy, strong backwash, weak wash, high frequency and high wave length while constructive waves are the opposite. Destructive waves are erosion while constructive waves are depositional
Explain rotational slumping
Rotational slumps occur when a slump block, composed of sediment or rock, slides along a concave-upward slip surface with rotation about an axis parallel to the slope.
Define abrasion
the process of scraping or wearing something away.
Define hydraulic action
Hydraulic action is the erosion that occurs when the motion of water against a rock surface produces mechanical weathering. Most generally, it is the ability of moving water to dislodge and transport rock particles.
Define attrition
the process of reducing something’s strength or effectiveness through sustained attack or pressure.
Define solution
The acidity in the water starts to erode rocks
Define traction
The rolling of large rocks on the surface of sea bed
Define saltation
The hopping of a medium pebble on the seabed
Define suspension
The suspension of small particles in water
Define solution
Soluble materials that have been dissolved in the water and are carried along
Describe long shore drift
Prevailing wind direction
Causes waves to approach the coast at the same direction. Swash moves sediment up the beach in the direction of the wind. Backwash moves sediment down the beach due to gravity. The next wave picks up the sediment. The sediment moves along the coastline
How is a split formed
When there is a sudden change in the coastline causing long shore drift to drop sediment off the shore. After a while a wind from another angle causes the split to curve. This creates shelter causing salt marsh. The split cannot travel to far as it cannot travel through deep water
Characteristics of a split
A split is a shallow long and thin body with 1 or more curves. The edges are all sand while the middle is grass.
