1. Tides and Currents Review sheet Answers

2. 1: draw and label the parts of a wave

3. Crest: it is the highest part of the wave
Trough: it is the lowest part of the wave
Wavelength: the distance from one crest to the next or one trough to the next
Wave height: the vertical distance between the crest and the trough

4. In a wave, only the ENERGY moves forward.
Why would you see breakers in the water?
The waves are near the shore.
How does wind cause a wave to form?
It moves water horizontally at the surface.

5. What is a spring tide and when does it occur?
A spring tide is a tide with the largest daily tidal range.
Spring tides happen when the sun, moon and earth are aligned. This occurs about every 14 days during a new-moon and full-moon phases.

6. What is a neap tide and when does it occur?
A neap tide is a tide with the smallest daily tidal range.
Neap tides happen when the sun, moon and earth form a 90 degree angle.
This occurs half way between the spring tides, which is during the first-quarter and third-quarter phases of the moon.

7. What is a tidal range?
A tidal range is the difference between levels of the ocean water at high tide and low tide.

8. What is a rip current?
It is an ocean current that moves perpendicular to the shore and sometimes can carry swimmers out to sea.

9. What causes high spring tides to occur?
High spring tides occur when the Earth, moon, and sun are aligned.

10. What causes the tides in the Earth’s ocean?
The tides are caused by the earth’s revolution around the sun.

11. How does ocean water differ from fresh water?
Ocean water has a higher level of salinity or sodium chloride.

12. What is the most important function of the ocean?
By giving off water vapor into the atmosphere to aid in the water cycle.

13. How do surface currents move…
In the Northern Hemisphere is moves clockwise
In the Southern Hemisphere is moves counter clockwise

14. What is a upwelling?
A upwelling is a slow moving, cold current that may rise to the surface. It carries food particles to the surface, resulting in areas of good fishing.

15. If there is an increase in salinity, density will also increase
If there is an increase in salinity, density will also increase. This causes a current to form.

16. If you are floating in the Gulf Stream on a raft, then you would travel in the direction of the current.

17. What is caused the by the Earth’s rotation and how does it effect the currents?
The Coriolis Effect is caused by the Earth’s rotation and this causes the currents to move along a curved path.

18. What do surface currents affect?
Surface currents will affect the climates on the continents.

19. Why is a rip current not an undertow or a rip tide?
A rip current will not pull you under the water and it does not change
levels daily.
It is a narrow powerful current that run perpendicular to the beach and out into the ocean along the surface.

20. What type of current produces a sandbar and how
A longshore current will produce or make a sandbar because it carries and deposits sediment as it travels parallel to the shore.