SALT WATER ON EARTH

Hydrosphere:Is all the water on Earth, wherever it is found and whatever state it is in, is called the hydrosphere.

Salt water: Over 97% of the Earth’s water is salt water and is located in oceans and seas.

Fresh water: Over 3% of the Earth’s water is freshwater and is located in ice caps and glaciers in the form of ice, and in rivers, lakes and groundwater in liquid state. There is also water in the atmosphere, in the form of clouds.

Oceans:Oceans are huge, deep bodies of salt water located between continents. In order of size, the five oceans are the Pacific, Atlantic, Indian, Antarctic, and Arctic

Seas:Seas are usually smaller parts of oceans and are normally close to/or enclosed by land. They are not as deep or as big as oceans.

WATER CYCLE:

The water cycle is the change in the state and the circulation of water on Earth.

1. Evaporation: Water is heated and transformed into water vapour, which disperses into the atmosphere.

2. Condensation: Water vapour cools and condenses into water droplets. Clouds form.

3. Precipitation: the water falls as rain, snow or hail.

4. Solidification: Liquid water gets colder and becomes ice.

5. Fusion: Water in a solid state heats up and melts.

6. Surface run-off: Liquid water falls from the mountains in rivers and streams. It eventually returns to the sea.

7. Infiltration: Some water infiltrates the ground and becomes groundwater. It eventually returns to the sea.

TYPES OF SEAS:

Continental seas:

They are connected to the ocean by a strait. The Mediterranean Sea is an example of this: it is connected to the Atlantic Ocean through the Strait of Gibraltar.

coastal seas:

are a part of the ocean and cover the area of the continental shelf. The Cantabrian Sea, China Sea and Caribbean seas are examples of this type of sea.

Closed seas:

are found on continents. They aren’t connected to other seas or oceans. Closed seas are not considered lakes because of their large size and salt water. The Caspian Sea and Dead Sea are examples of this type of sea.

OCEANS CURRENTS:

Ocean currents flow like vast rivers, travelling along predictable paths. Some ocean currents flow at the surface; others flow deep within the water. Some currents flow for short distances; others cross entire oceans and even circle the globe. Ocean currents are caused by wind, temperature changes and salinity in different water masses. They can be warm or cold:

Warm currents come from areas with warm climates. The water moves westward until it meets a continent, which makes it turn in the opposite direction.

Cold currents come from polar areas, and travel towards tropical areas. They cool down the coasts they pass and can bring icebergs with them.

WAVES:

Waves are movements on the surface of the sea. Wind usually forms them.Wind carries them towards the shore.

Oscillating movement:Out to sea, away from the shore, waves move up and down oscillating, but they don’t move forward.

Drag movement: When they arrive, they crash onto the land and produce the drag movements we see on the shore.

TIDES:

Tides are the daily increases and decreases in the level of the sea. When sea level is at its greatest height, it is high tide. When it drops to its lowest height, it is low tide. Tides happen because of the power of gravity that the Moon and (to a

lesser extent) the Sun, have on Earth.