Ocean Water Characteristics

Depth, Salinity and
Temperature of the

Ocean Water

Learning Targets

SCI.4.7.1 Construct a model of the ocean floor and label and describe each of the major features.
SCI.4.7.2 Compare and contrast the formation of ocean water movements as related to currents, waves,
and tides. (SOL 4.7b)

Physical Features

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● As the depth of ocean water increases, the temperature decreases.

● As the depth of ocean water increases, the amount of light decreases.

(The deeper you go the colder the water will be)

(The deeper you go the darker it will be)

● Light from the sun warms the ocean

• The warmest temperature is near the surface of the ocean

• The deeper one travels in the ocean, the greater the pressure

Salinity =

the amount of dissolved salt in water

●Salinity is dependent upon the balance of precipitation and evaporation.

●Salinity is highest in places where precipitation is low and evaporation is high.

●Salinity is also dependent on the amount of run-off from land as well as the

melting of icebergs.

●Both salinity and temperature determine the density of water

Ocean Water

Movement

WAVES

●Waves are a moving ridge on the surface of the ocean caused by the wind.

●Waves are defined as the movement of water that occurs on the surface of water.

●The faster the wind, the longer it blows the bigger the waves.

TIDES

●Tides are the rise and fall of sea level caused primarily by the gravitational pull
between the Earth and moon.

●The gravity of the Moon causes a high tide on the sides of the Earth directly below
the Moon. The level of the ocean rises and water covers the shore.

●Low tides are on the sides of the Earth away from the Moon.the level of seawater
falls. The seashore is uncovered.

CURRENTS

●Currents are continuous, directed movements of a large body of water caused by
wind patterns and differences in salinity and temperature.

●Currents can be near the surface or in the deep ocean.
◆

Surface currents are usually caused by the wind. As the wind changes, the
current may change as well.

◆

Deep ocean currents are caused by a number of things including changes in
the temperature and salinity of the water.

CURRENT EXAMPLE

The Gulf Stream is a warm Atlantic Ocean current. It moves north along the coast of
Florida and then turns eastward off of North Carolina, flowing northeast across the
Atlantic.

Name of ocean movement

Cause

Effect

Directions: Complete cause and effect sort in Science Notebook

Waves

Currents

Tides

Caused by wind

Caused by the moon's

gravitational pull

Caused by wind,

different in temperature

and salinity

Mixes ocean water

Crest- highest point of the wave
Trough- lowest point of the wave

Causes measurable changes
in the levels of ocean water

High tide- the side closest to the moon
Low tide- the side away from the moon

Raises temperature of

ocean water

Surface currents- caused by wind.

Deep currents- caused by temp and salinity levels.

Multiple Choice

Which ocean movement is the rise and fall of sea level?

• Tides

• Waves

• Currents

• Streams

Multiple Choice

What ocean movement is a circular continuous, directed movement of a large body of water?

• Slopes

• Currents

• Waves

• Tides

Multiple Choice

Which of the following is a warm Atlantic Ocean current?

• The Equator

• The North Stream

• The Gulf Stream

• The Abyssal Plain

• The Continental Rise

Multiple Choice

As the depth of the ocean water increases, the pressure __________________.

• Doesn't matter

• Decreases

• Stays the same

• Increases

Multiple Choice

What causes waves in the ocean?

• wind

• the gravitational pull of the moon

• differences in salinity and temperature

• people

Multiple Choice

What happens to the amount of light as the depth of water increases?

• Increases

• Decreases

• Remains the same

Multiple Choice

What causes tides?

• wind

• the gravitational pull of the moon

• differences in salinity and temperature

• people

Multiple Choice

Salinity is -

• the amount of sand in the ocean

• the amount of animals in the ocean

• the amount of water in the ocean

• The amount of salt in the ocean

Multiple Choice

As you go deeper into the ocean, the water gets

• warmer and salty

• colder and salty

• colder and less salty

• freezing and salty

Multiple Choice

What are two types of currents?

• local and global

• coastal and inland

• deep and surface

• deep and swift

Multiple Select

The three basic movements of the ocean that cause ocean water to mix are -

• currents

• waves

• swimming and surfing

• tides

Multiple Choice

True or False Salinity increases as ocean depth increases.

• True

• False