Tides Tides- rise and fall of water levels in oceans that occur every 12.5 hours Rises for 6 hours, falls for 6 hours Tides are caused mainly by differences in how much the moon’s gravity pulls on different parts of Earth. At any one time, there are two places with high tides and two places with low tides
Spring Tide- both the sun and moon pull on the ocean water (high tide is more extreme) Neap tide- the sun and the moon pull opposite of each other (high tide is less extreme)
Spring Tides During a new or full moon, the gravitational pull of the moon and sun are combined. High tides are very high and the low tides are very low.
Neap Tides During the moon's quarter phases the sun and moon work at right angles, causing the tides to cancel each other. The result is a smaller difference between high and low tides Gravitational forces of the Moon and the Sun are perpendicular to one another (with respect to the Earth).
Look at the following pages to identify these characteristics: Page 26 and review figure 16 Page 27 and review figure 17