- Slides: 6
TIDES • Tides: the daily rise and fall of ocean water. • What Causes Tides? • The force of gravity pulls the moon and Earth toward each other. • Gravity: the attractive force between 2 objects. • Tides occur mainly because of difference in how much the moon pulls on different parts of Earth. • As Earth rotates, the moon’s gravity pulls water toward the point on Earth’s surface closest to the moon.
HIGH TIDES A C D B
THE TIDE CYCLE • As Earth rotates, one high tide stays on the side of Earth closest to the moon and on the side opposite the moon. • Every location on Earth sweeps through those two high tides and two low tides in a daily tide cycle.
SPRING AND NEAP TIDES • The sun’s gravity also pulls on Earth’s waters. • When the sun, moon, and Earth are all in a line, Earth has a spring tide. • Spring Tide: a tide with the greatest difference between low and high tide. • Occurs twice a month during the following 2 moon phases: • New Moon • Full Moon
SPRING AND NEAP TIDES • When the sun and moon are at right angles to the Earth, Earth has a neap tide. • Neap Tide: a tide with the least difference between low and high tide. • Occurs twice a month during the following 2 moon phases: • First Quarter • Third Quarter