Waves Flashcards
(30 cards)
What are waves>
Waves are the oscillation (back and forth movement) of the water surface
What shapes waves?
Wind blowing over a smooth sea surface causing ripples which grow into waves
What else could control waves?
Tides and earthquakes (tsunamis)
What controls the wave energy and size?
Wind strength and duration
Fetch
Depth of seabed
Once created, what direction do waves move in?
The direction of the wind
What happens to water particles when a wave passes through?
Water particles simply rotate in a circular or elliptical movement as the wave passes through. It is the energy of the wave that moves towards the shore, not the water in the wave
When does the movement of the wave energy translate into movement of water towards the shore?
When a wave breaks
What are waves reaching the shore known as?
Waves of translation
What happens when wave base comes into contact with the seabed?
Friction slows down the wave advance which causes the wave front to crowd together
What happens after the wave front crowds together?
The shortening of the wave causes an increase in wave height
What is a spilling wave?
- Wave crest becomes unstable and spills down while introducing air bubbles inside
- Foamy water
- High-steepness waves over mild slopes
What is a plunging wave?
- Wave shoreward face becomes first vertical, curls over and finally plunges into the water ahead
- Air can be trapped inside the curl
- Medium steepness waves over intermediate slopes
What is a collapsing wave?
- Wave crest becomes vertical, until the base collapses arriving to the shoreline as a thin water layer
- Low steepness waves over steep slopes
What is a surging wave?
- Wave crest remains unbroken, and the wave arrives to the shoreline with small shape changes
- Low steepness waves over very steep slopes
What are all the characteristics that need to be labelled in the cross section of a wave?
Trough, crest, wave length, circular motion, wave height, still water level
What makes waves?
Waves are created by energy passing through water, causing it to move in to a circular motion. However, water does not actually travel in waves
Do waves pass water across the ocean?
No, waves pass energy across the ocean
What does wave refraction do?
Reduces wave velocity and, if complete, causes wave fronts to break parallel to the shore. Concentrates energy onto the sides of headlands and dissipates energy in bays
What is a constructive wave?
What is a destructive wave?
What are the characteristics of constructive waves?
What are the characteristics of destructive waves?
What type of waves erode the coastline?
Destructive
What type of waves create wide, flat beaches?
Constructive
