Surf Environment

Question 1

What is a wave and how is it formed?

Answer 1

A body of water moving along the surface of the ocean.

Question 2

What factors can affect the size of waves?

Answer 2

1. How hard the wind blows - Velocity
2. The length of time it blows - Duration
3. The distance it blows - Fetch

Question 3

What is a tide?

Answer 3

The alternating rise and fall of the surface of the sea caused by the attraction of the moon and the sun twice in 24 hours.

Question 4

What is a flood tide?

Answer 4

When a tidal current moves towards the land and away from the sea.

Question 5

Explain how changes in the tide can affect surf conditions?

Answer 5

1. The tide can change the wave types by exposing sand bars and holes.
2. Change current directions
3. Rip currents are stronger on outgoing tides

Question 6

Does the tide affect waves on your beach, if so how?

Answer 6

There is a Rip tide at Orewa estuary between the second and third hours.

Question 7

What is a Rip?

Answer 7

A narrow body of water moving out to sea when large quantities of water need to find a way back out to sea.

Question 8

Name 4 identifying features of a Rip.

Answer 8

1. Calm patches in the surf with waves breaking each side.
2. Rippled or Criss-crossed water
3. Discoloured, sandy water
4. Foamy water

Question 9

If you need to escape from a current.

What are the 3 Rs?

Answer 9

Relax
Raise your hand
Ride the rip

Question 10

Describe a Boundry Rip.

Answer 10

Stationary all year round

Question 11

Describe a Channel Rip

Answer 11

Occupies deep holes or gullies on the ocean floor with sand ad it’s primary base.

Question 12

Describe a Flash Rip Current

Answer 12

Temporary Rips generated by increased volumes of water brought on to the shore.

They occur without warning and stop rapidly.

Question 13

How are holes formed?

Answer 13

Where waves, tides and currents scour out a deeper area on the sea floor.

Question 14

How can you be sure where holes are located?

Answer 14

Observation.

Observe at low tide - easier to see where holes are.

Question 15

There are two main types of winds you may experience at the beach.

What are they and how do they affect the surf conditions?

Answer 15

1. Offshore winds - when the wind blowing from the land out to sea.

It causes cleaner surf conditions with regular waves.

2. Onshore winds - when the blows from the sea towards the land.

It causes the surf to be choppy and irregular waves.