They are created from big, strong waves
when the wind is powerful and has been blowing for a long time
. They occur when wave energy is high and the wave has travelled over a long fetch. They tend to erode the coast.
What do destructive waves have?
Destructive waves have a
large wave height and short wavelength
. They have tall breakers that have a high downward force and a strong backwash. Their frequency is high with between 13 and 15 waves per minute. Their strong downward energy helps erode beach material and cliffs.
How is a constructive wave formed?
Constructive waves predominate in calmer weather conditions when less energy is being transferred to the water. Each wave is low. As the
wave breaks it carries material up the beach in its swash
. The beach material will then be deposited as the backwash soaks into the sand or slowly drains away.
Where are destructive waves?
Destructive waves are usually found in
more exposed bays
, where they build pebble beaches. Although a destructive wave’s swash is much stronger than that of a constructive wave, its swash is much weaker than its backwash.
Why do destructive waves cause erosion?
Destructive waves have
stronger backwashes than swashes
. This strong backwash pulls material away from the shoreline and into the sea resulting in erosion.
Do destructive waves have a strong swash?
Destructive waves
weak swash
and strong backwash. the strong backwash removes sediment from the beach.
Where do the biggest waves start?
The waves that surfers ride originate in
distant storms far across the ocean
. For instance, the wave that Gabeira surfed at Nazaré was likely generated by a storm somewhere between Greenland and Newfoundland a few days earlier.
Why do destructive waves have a weak swash?
| Characteristic Constructive Destructive | Swash Strong Weak | Backwash Weak Strong | Wave height Low High |
|---|
What does a destructive wave look like?
Destructive waves
They occur when wave energy is high and the wave has travelled over a long fetch. They have a stronger backwash than swash. They have
a short wave length and are high and steep
.
What causes high energy waves?
Waves are most commonly caused by
wind
. Wind-driven waves, or surface waves, are created by the friction between wind and surface water. As wind blows across the surface of the ocean or a lake, the continual disturbance creates a wave crest.
Are destructive waves tall?
Destructive waves have a
large wave height and short wave length
. They have tall breakers that have a high downward force and a strong backwash. Their frequency is high with between 13 and 15 waves per minute. Their strong downward energy helps erode beach material and cliffs.
Is a destructive wave plunging or spilling?
| Constructive waves Destructive waves | Swells and spilling breakers* Plunging and surging breakers* | Occurs on sheltered coasts Occurs on exposed coasts. |
|---|
Where in the UK has the largest fetch?
The South West of Britain is affected by waves that have an incredibly long fetch, as the South Westerly winds which blow the sea there travel uninterrupted for thousands of miles across the Atlantic Ocean. It is for this reason that the waves are large in
Cornwall
and generally great for surfing!
What are 4 types of erosion?
Rain, rivers, floods, lakes, and the ocean carry away bits of soil and sand and slowly wash away the sediment. Rainfall produces four types of soil erosion:
splash erosion, sheet erosion, rill erosion, and gully erosion
.
How do waves affect erosion?
When a
wave breaks, the trapped air is compressed which weakens the
cliff and causes erosion. Abrasion: Bits of rock and sand in waves grind down cliff surfaces like sandpaper. Attrition: Waves smash rocks and pebbles on the shore into each other, and they break and become smoother.
What can we do to stop coastal erosion?
Present beach erosion prevention methods include
sand dunes, vegetation, seawalls, sandbags, and sand fences
. Based on the research conducted, it is evident that new ways to prevent erosion must be obtained. Each way that is currently used has extensive negative effects on beaches and their natural tendencies.
