Ocean Tides

1
Ocean Tides
2
Tides

• The tides on Earth are created by the
  gravitational pull of the moon and the sun on the
  Earth.
• The moon is much closer to the Earth than the
  sun, therefore the moon has a greater affect on
  the tides.

3
How many tides in a day

• Every place on Earth experiences two high and two
  low tides a day.

4
Tides

• High tide is always occurring in two places on
  the Earth, and low tide on two places also.
• The moons gravity pulls on the Earths surface.
  Since water is a liquid it can stretch.
• Gravity from the moon stretches the water causing
  it to pile up creating a tidal bulge.

5
High and low tides
6
(No Transcript)
7
Two Special Tides

• Two types of tides occur twice a lunar cycle.
• Spring Tides and Neap tides each occur twice a
  lunar cycle.
• Spring and Neap tides are described on the
  following slides.

8
Special tides

• Neap tides occur when the sun, earth and moon
  create a right angle.
• There are two neap tides every lunar cycle.
• Neap tides create the lowest high tides and the
  highest low tides. In other words the tidal
  range is small across the Earths surface.

9
Tidal Range

• The difference between sea level at high and low
  tide.

10
Neap tides
11
Neap Tides

• During what lunar phases do neap tides occur?

12
Neap Tides

• Neap tides occur on the first and third quarter
  moon phases.

13
Special tides

• Spring tides occur when the sun earth and moon
  are aligned.
• The gravitational pull of the moon and sun add up
  to have a greater affect on the tide.
• Spring tides occur twice every lunar cycle.
• Spring tides create the highest high tides and
  the lowest low tides.
• Spring tides have the greatest tidal range.

14
Spring Tides

• During which lunar phases do spring tides occur?

15
Spring Tides

• Spring tides occur on the full and new moon.

16
Spring tides
17
(No Transcript)