Changing Rates of Recession

Question 1

Rates of recession are not constant
They

Answer 1

Wind direction/fetch
Tides
Seasons
Weather systems
Occurrence of storms

Question 2

Wind direction and fetch
Wind direction at the coast varies and may change every day

The wind can be onshore or offshore
Rates of erosion (and so recession) are greater when winds are blowing onshore

In most areas, wind generally comes from one main direction - this is known as the prevailing wind direction

When prevailing wind direction is also the direction of the largest fetch this can lead to the build-up of large destructive waves causing rapid erosion

Question 3

High tide occurs twice a day
Twice a month the Sun, Moon and Earth are in alignment increasing the gravitational pull; this causes the highest tide known as a

Answer 3

spring tide

Rates of recession are greatest during high tide because this is the time when the water and waves reach the backshore

The waves also have more energy when they reach the backshore leading to more erosion

Question 4

Seasons
Rates of recession are likely to be greater in winter than in summer because

Answer 4

storm events that cause destructive waves are more common in winter months
Weather systems

Question 5

The UK is located between warm tropical air and cold polar air

It experiences periods of both high pressure (anticyclones) and low pressure (depressions)
During anticyclones there are

during depressions

Answer 5

gentle winds and low waves, so rates of recession are low

the winds are much stronger, leading to high waves and greater rates of recession

Question 6

Storms
Storms lead to high energy, destructive waves

These waves increase the rate of erosion and therefore, coastal recession

In Cornwall, over a two-week period, …………..cubic metres of cliff face was eroded along a 300-metre stretch of coastline, as a result of the 2013/14 storms

Answer 6

1350