Unit 1: Water Systems on Earths...

transcript

Unit 1: Water Systems on EarthChapter 2

Create a mind map with the driving question, ”Why are Oceans Important?”

Why are oceans so important?

Remember:

• Primary water source for the water cycle

• Major influence on weather and climate

• Support diverse life

• Provides humans with food, minerals, and other resources

5 Major Oceans

What are the 5 major oceans in the world?

5 Major Oceans

• Pacific

• Atlantic

• Indian

• Southern

• Arctic

How were oceans formed?

1.Tectonic Plates

2.Volcanic Action

3.Erosion

4.Glaciation

Tectonic Plates

Tectonic plates: slow moving sections of rock that float over a layer of magma

• The surface of the earth is made up of tectonic plates

• Tectonic plates separating formed the oceans we know today

Tectonic Plates

• At ocean ridges- plates are separating

• At ocean trenches- plates are colliding

Volcanic Action

• Water trapped in volcanic materials was released as vapour, cooled, condensed and fell back to the earth

• This water collected in the lowest parts of the Earth’s surface...the ocean basins

• Volcanic activity continues to occur at ocean ridges, spreading tectonic plates apart and adding new material to the sea floor

Erosion

Erosion: type of weathering in which surface soil and rock are worn away through the action of glaciers, water, and wind

• Has aided the development of continental drainage systems as material is removed and deposited into ocean basins

Glaciation

• Glaciers move materials towards the ocean and cause erosion

What does the seafloor look like?

Components of The Ocean Floor

Continental Margin

• Ocean basins begin many kilometres out to sea

• The area between the basin and the coastline is called the continental margin

Continental Margin

• Ocean basins begin many kilometres out to sea

• The area between the basin and the coastline is called the continental margin

• This is made up of the• Continental shelf

• Continental slope

Continental shelf• the submerged part of the continent between the shoreline and

Continental slope• The slope between the continental shelf and the deep ocean floor

Abyssal Plains

• Wide, open plains (flat areas) on the deep sea floor

• Formed of thick deposits of sediments

Mid-Ocean Ridge• Long, undersea mountain chains formed from volcanic eruptions• They are a result of magma that has oozed up between

plates and then hardened.

Ocean topography off the coast of Newfoundland

Ocean Currents

Ocean current:• A continuous, directional movement of ocean water

Ocean Currents

2 Types of Ocean Currents...

1. Surface currents• Flow in the top 100-200 m

2. Deep currents• Flow below 200 m

Surface Currents

Factors that influence surface currents are:

1.Wind

2.Earth rotation

3.Shape of the Earth’s continents

Deep Water Currents

Factors that influence deep currents are:

1.Differences in Water temperature

• Cold water is more dense- sinks

2. Differences in Salinity

• Water with a higher salinity is more dense – sinks

•ocean currents video

Ocean Currents

Local Ocean Currents...

1. Labrador Current (cold water)

2. Gulf Stream (warm water)• Refer to map p. 54

Ocean Currents

Local Ocean Currents...

1. Labrador Current (cold water)

2. Gulf Stream (warm water)• Refer to map p. 54

• When the cold air above

the Labrador Current

meets the warm air above

the Gulf Stream, the warm

air, cools condenses and

forms fog

Ocean Waves

Waves: a disturbance on the surface of the ocean that transmits energy

•Waves are typically caused by wind

Ocean Waves2 Main Types of Waves:

1. Swells • Smooth waves caused by wind and

storms far out in the ocean

2. Breakers• the tumble of water when a wave

collapses onshore

Ocean Waves

*Tsunamis

• giant waves caused by earthquakes, landslides or volcanic eruptions

• Can be very destructive .

Tides are• The slow rise and fall of the ocean• The upper and lower edges of a beach are determined by

the high and low tide marks.

• Tides are caused by the gravitational pull of the moon and the spinning of the

• The moon exerts a greater force of pull than the sun due to its closer proximity to Earth.

Tidal Range:• The difference in level between a high and a low tide

Tides2 Types of Tides:

1.Spring Tide:

• Occur when the Earth, Sun and Moon are in a line.

• Causes extra high and low tides.

2. Neap Tides:

• Occur when the Sun and the Moon are at right angles to one another.

• Causes the smallest tidal movements. There is little difference between low and high tides

Tides2 Types of Tides:

Shaping our Shorelines• Waves have the power to erode and deposit sediments on the

shore.

• Tides work with waves to determine the range of shoreline that can be affected by wave action.

Factors that affect the interaction of waves and tides on the shorelines are:

1. Slope of the shoreline 2.Shape of the shoreline

3. Type of rock material 4.Wave energy

Shaping our Shorelines

Wave energy is concentrated on headlands and spreads out as it reaches bays

Coastal erosion can lead to many shoreline features

• Headlands

• Sea caves

• Sea Arches

• Sea Stacks

Think-Pair-Share...

•write down two-three points• get together with a partner and discuss• share with the class

How can coastal communities minimize the damage to shoreline property due to waves and tides

Wave energy is concentrated on headlands and spreads out as it reaches bays

Unit 1: Water Systems on Earths...

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