Ocean Water

Most of the water going into and coming from the water cycle is in oceans.

Oceans formed over a period of millions of years as rain filledlow areas of earth (basins).

Today, Earth is approximately 70% ocean water.

Ocean water contains many elements from volcanoes, groundwaterand rivers.

The two most common elements in ocean water are sodium (Na)And chloride (Cl).

Sodium comes from rivers that carry sediment in to the ocean,While chloride comes from underwater volcanoes.

Na and Cl combine to form a salt called halite (NaCl).

Ocean water also contains calcium (C), potassium (K),Sulfur (S) and magnesium (Mg).

On average, ocean water contains 3.5% salt.

Salinity - the measure of the amount of salt in water.

The salinity of the ocean remains relatively stable.

For example, if you have a 100 ml sample of water to which3 g of salt is added, it has a salinity of 3%.

Ocean Currents - water moves from place to place

1. Surface Currents - affect only the upper part of the ocean; usually caused by wind (friction between air and water surface causes movement)

Surface currents affect climate.

They are warm or cold depending on where they originate.

North of the equator, currents tend to move clockwise.South of the equator, currents move counterclockwise.

How might some of the currents above affect the climateof the area they move towards?

2.) Density Currents - caused when denser, cold water mixeswith warmer, less dense water

Upwelling - cold, dense water rises to the surface

How do you think the density of salt water would vary fromthat of fresh water?

Density = Mass/Volume

Unit for density = g/cm3

How do you find the volume of an object?

1.) displacement (used for irregular shaped objects)

2.) Length x width x height (used for regular shaped objects)

Waves - alternate rise and fall of ocean water

Ocean waves are usually caused by wind energy.

In water waves, each particle of water moves in a circularmotion. However, the particles do not actually move forward.The energy moves forward by being passed from one particle to another.

Water waves can also be caused by some underwater disturbance, such as an earthquake.

Tides - long waves resulting in periodic changes in theSurface level of oceans

Tides are caused by the gravitational effect of the moon, sun and Earth.

The moon exerts a strong gravitational pull due to its closeproximity to the Earth. When water bulges on the side of theEarth facing the moon and the side directly opposite, this is high tide.

Each day, there are two high and two low tides.