PRESENTATION OUTLINE
Waves are formed by wind blowing against them. Waves start very small and grow more and more as more wind pushes against them. The size of the wave is controlled by how fast the wind blows and how long the wind blows
Plunging waves are waves that are in the shape of a tube or barrel. They are often called dumping waves. Plunging waves happen when waves travel from deep to shallow water quickly and have to slow down very fast.
Spilling waves are the safest waves to swim in. They are much gentler because the crest of the wave gently spills down the front face as it breaks. They happen when waves go from deep to shallow water not too quickly.
Surging waves are waves that do not plunge or spill. They build up near the shore and then crash. They happen on most beaches usually during smaller swell.
A tsunami is a giant wave that is caused by undersea earthquakes, volcanic eruptions, or landslides. They are sometimes called tidal waves but tidal waves and tsunamis are not the same.
Dissipative beaches are also called high energy beaches. The water at these beaches flows back seaward so there are no rips. These beaches never really change much at all. In Australia, they are most common in South Australia because the waves are large and the sand is smaller.
Another kind of beach is a reflective beach. They are also known as low energy beaches because they have smaller waves and more sand. They tend to be steep and narrow beaches with no rips or currents. The waves are plunging waves that crash at the shoreline.
There is also another kind of beach called bar and rip beaches. They are also called intermediate beaches. These beaches have medium size waves and sand. They have lots of sand bars and rip currents. They also change all the time! You can find a lot of these beaches in NSW.
The tide is the rising and falling of the sea, usually twice a day. The rip currents flow the fastest at low tide which makes the beach more unsafe. It flows the slowest at high tide and the rips can even stop at high tide.
Onshore winds are winds that are blowing onshore. When it's onshore, the surf isn't very good. Offshore winds are winds blowing away from the beach towards the water. That makes the waves better and bigger.
