Ocean Waves and Tides Objectives Define a wave

Ocean Waves and Tides Objectives: Define a wave and explain the difference between the movement of water particles and wave energy

Waves • A wave is a rhythmic • • motion that carries energy through matter or space. Crest: highest point of a wave. Trough: lowest point of a wave

Wave Movement • Each molecule of water • stays in about the same place as the wave energy passes through. When a wave nears the shore, the friction of the ocean bottom causes water there to slow down while the top molecules are still moving quickly. This causes a breaker.

Waves caused by wind • When wind blows across the surface of the water, the friction of the air molecules against the water molecules creates a pile up of water. • The height of these waves depends on speed, distance and length of time the wind blows.

Tides • Tides are the rise and fall • • in sea level Tides are caused by a giant wave that is only 12 meters high but thousands of kilometers long. This giant wave is caused by the moons gravitational pull along with some pull from the sun.

The Gravitational Effect of the Moon • A daily cycle of two low-tides and two high-tides takes 24 hours and 50 minutes, this is the time it takes the moon to circle the Earth!

The Gravitational Effect of the Sun • The sun can • • strengthen and combine with the moon’s gravitational pull or it can work against it Spring tides: Sun in line with moon Neap tides: Sun at right angle to moon