Waves, Rips and Currents Flashcards
How are waves formed?
They are created from wind blowing over the surface of the water.
when will a wave break?
Waves break on shore when the shape of the wave becomes too steep and this usually happens as waves travel from deep water to shallow water. This causes the waves to slow down, increase in height and become steeper until they break.
What are the three main types of waves?
Plunging, Spilling, Surging
More infö on spilling waves
Spilling- Where the beach is relatively flat and wide, spilling breakers will form.
More infø on Plunging waves?
Plunging- With a slightly steeper beach slope, the crest curls over and creates a plunging breaker.
More infø on surging waves
Surging- These waves do not plunge or spill, but bulge up near the shoreline and then rush up the beach very quickly.
What is an offshore breeze
In the day, when the sun is up, the land heats up very quickly and the air above it warms up a lot more than the air over the water. The warm air over the land is less dense and begins to rise. Low pressure is created.
The air pressure over the water is higher with cold dense air, which moves to occupy the space created over the land. The cool air that comes along is called a sea breeze.
What is an onshore breeze
The land quickly loses its’ heat whiles the water retains its’ warmth. This means the air over the water is warmer, less dense and begins to rise. Low pressure is created over the water. Cold and dense air over the land begins to move to the water surface to replace the warmer rising air. The cool breeze from the land is called a land breeze.
What is a rip
Rips occur when large sets of waves break on the beach and a build up of water is rushing back out to sea.
This water hurries to find the quickest way back out to sea, creating a strong current out past the surf zone.
What are the types of rips
Fixed, Flash and headland rips
What is an ocean current
An ocean current is a continuous movement of ocean water from one place to another
What does the currents speed and direction depend on?
depends on the shoreline and the ocean floor
Which way do surface currents travel in the NH and SH
Northern Hemisphere: Clockwise
Southern Hemisphere: Anti-Clockwise
What are the factors influence deep water currents?
changes in water density, temperature and salinity (salt content)
