Processes Flashcards
What is a tide? (Processes coasts)
Variation in sea level caused by the gravitational pull of the sun and the moon
Why does a neap tide occur? (Processes coasts)
When the Earth, moon and sun form a right angle, distorting gravitational pulls
What are the characteristics of a neap tide? (Processes coasts)
Lowest high tides
Highest low tides
Why does a spring tide occur? (Processes coasts)
When the Earth, moon and sun are all in line
What are the characteristics of a spring tide? (Processes coasts)
Highest high tides
Lowest low tides
What are the erosional processes? (Processes coasts)
Hydraulic action
Attrition
Abrasion
Solution
What is hydraulic action? (Processes coasts)
Waves break at the foot of a cliff causing air to be blasted into cracks, loose rocks are dislodged and the cliff becomes undercut and retreats
What is attrition? (Processes coasts)
Bits of rock in the water smash against each other and break into smaller bits
What is abrasion? (Processes coasts)
When rocks carried by sea water bash against the cliffs and wear down (sandpaper effect)
What is solution? (Processes coasts)
Pebbles and sediment are dissolved
How can material be transported? (Processes coasts)
Traction
Saltation
Solution
Suspension
What is traction? (Processes coasts)
Large and heavy rocks are rolled along the sea bed
What is saltation? (Processes coasts)
Small/light rocks adopt a bouncing motion along the river bed
What is solution? (Processes coasts)
Sediment that has dissolved completely
What is suspension? (Processes coasts)
Light sediment is carried within the water, accounting for the murky appearance of the sea
What is LSD? (Processes coasts)
The process whereby waves hit the beach at a slight angle
Swash dies away
Backwash falls straight back (90 degrees to the beach)
What is deposition? (Processes coasts)
When sand is deposited on a beach, it dries and may be taken away by wind
occurs in low energy environments
What are the types of weathering? (Processes coasts)
Sub-arial Freeze thaw Salt weathering Wetting and drying Carbonation Biological
What is sub-arial weathering? (Processes coasts)
The gradual breakdown of rocks in their original place (in-situ)
What is freeze-thaw? (Processes coasts)
With regular freezing and thawing, some fragments of rock break away and collect at the base of the river
What is salt weathering? (Processes coasts)
When salt evaporates from the rocks it leaves behind salt crystals that crack the rock apart
What is wetting and drying? (Processes coasts)
Clay rich rocks expand when they get wet and contract when dry causing them to crack and break up
What is carbonation? (Processes coasts)
the slow dissolving of calcium carbonate
What is biological weathering? (Processes coasts)
Plants prising apart rocks on cliffs
What is mass movement? (Processes coasts)
the downhill movement of rock and soil in response to the force of gravity
What ways can mass movement be seen? (Processes coasts)
Soil creep Mud flow Rational slip Landslides Rockfall
What is soil creep? (Processes coasts)
Very slow downhill movement of individual rock particles
What is mud flow? (Processes coasts)
Saturated soil flows downhill, often triggered by heavy rain
What is rational slip? (Processes coasts)
Common coastal landslides in weak rock e.g clay
What are landslides? (Processes coasts)
Rapid movement of detached slabs of rock
What is rockfall? (Processes coasts)
individual rock fragments fall due to freeze-thaw
What is a sediment cell? (Processes coasts)
A stretch of coastline, usually bordered
by two prominent headlands, where the movement of
sediment tends to be contained
