Waves

Important Pts. To Remember

• The transfer of ENERGY from wind to water makes waves.• The waves move, NOT the water

Wave Parts

• When waves come near the shore, their wave height INCREASES.

2 Types of WavesDeep Water and Surface Waves:• Deep-Water waves move in water deeper

than one-half their wave length. They are denser and slower.

• They become surface waves when they move toward the shore. They affect the climate on continents.

Tides

What are tides?• The periodic rise and fall of ocean

water.• Influenced by the sun and the

moon’s gravitational pull.

High Tides• When part of the ocean is directly facing

the moon, the moon’s gravity is pulling the ocean water into a bulge.

• At the same time, water on the opposite side of the Earth bulges because of the Earth’s rotation and motion of the moon.

Low Tides• When high tides occur, water is drawn away

from the area between the high tides, which causes low tides to form.

Timing of Tides• The moon revolves around the Earth

much more slowly than the Earth rotates.

• High and low tides occur twice a day, approx. every 12 hrs.

• Ex. If the first high tide of the day occurs at 2 a.m. the next high tide will occur at 2 p.m.

Spring TideSun, moon and earth are in a line.Occurs twice every 28 days.

Neap TideThe sun, earth, and moon are at a 90 degree angle.Occurs twice every 28 days.

Currents• Streamlike movements of ocean water, caused

by wind, that follow a pattern.

Surface Currents• Horizontal streamlike movements of

water that is caused by wind and that occur at or near the surface of the ocean.

• Like blowing on hot chocolate: forms ripples

• Affect the climate on continents by moving cold and warm water around the globe.

Deep Currents• Streamlike movements of ocean

water far below the surface.• Denser and slower than surface

currents due to temperature and salinity.