1. Ocean Motion

2. Wave They obtain their energy and motion from wind. Crest
The tops of the waves
Trough
The bottom of the waves

3. Anatomy of a Wave Picture

4. Wave Characteristics Wave height
The vertical distance between the trough and crest
Wavelength
The horizontal distance between two successive crests OR two successive troughs
Wave period
The time it takes one full wave (wavelength) to pass a fixed position

5. Wave characteristics are dependent on three factors:
Wind speed
Length of time wind has blown
Fetch
Distance the wind traveled across open water

6. Wave Motion
The water does not travel the entire distance, but the wave does.
Consider the following: a floating object on the water such as a rubber duck
What motion does the duck exhibit? (Forward motion or up and down or both – Explain)

7. Particle Motion
Circular orbital motion allows energy to travel forward yet the individual water particles only move in a circle

8. Breaking Waves As the original wave advances toward shore:
It begins to “feel bottom” at a water depth = ½ of its wavelength

9. Tides Daily change in the elevation of the ocean surface.
Ocean tides result from the change in the gravitational attraction exerted upon Earth by the moon and the sun.

10. Ocean Tides The moon is the primary body influencing ocean tides
It takes the moon 29 ½ days to make one revolution around the Earth
The sun is farther away so it has a much smaller affect on ocean tides.

11. Gravitational force
The moon pulls the ocean water creating a bulge on the side closest to the moon
Therefore, the side farthest from the moon has less pull

12. Tidal Cycle The sun has some influence on tidal bulges
Its influence is most noticed at full and new moons as they sun and moon are aligned
Alignment = combined forces pulling on the Earth’s water
Larger tidal bulges (higher hide tides) are created as are larger tidal troughs (lower low tides)

13. Tidal range
Difference in height between successive high and low tides
Spring tides
Tides having the greatest tidal range due to the alignment of the Earth, moon & sun
Experienced during full and new moons
2 per month
Neap tides
When the daily tidal range is the least
Experienced at the first and third quarters of the moon (when the moon and sun act on Earth at right angles)

14. Tidal Cycle

15. Tidal Patterns Three main tidal patterns: Diurnal tides
Semidiurnal tides
Mixed tides

16. Diurnal tides
A single high tide & a single low tide each day
Gulf of Mexico
Semidiurnal tides each day
Two high and two low tides
Both high or low tides are at the same height
Atlantic coast of U. S.
Mixed tides (Diurnal and semidiurnal each day)
Large inequality in high water heights and/or low water heights
Pacific Coast of U. S.