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Unit 1: Water Systems on Earth Chapter 2
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:
Why are oceans so important?
• Primary water source for the water cycle
Why are oceans so important?
• Primary water source for the water cycle
• Major influence on weather and climate
Why are oceans so important?
• Primary water source for the water cycle
• Major influence on weather and climate
• Support diverse life
Why are oceans so important?
• 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?
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
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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
• This is made up of the• Continental shelf
• Continental slope
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Components of The Ocean Floor
Continental shelf• the submerged part of the continent between the shoreline and
slope
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Components of The Ocean Floor
Continental slope• The slope between the continental shelf and the deep ocean floor
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Components of The Ocean Floor
Abyssal Plains
• Wide, open plains (flat areas) on the deep sea floor
• Formed of thick deposits of sediments
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Components of The Ocean Floor
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.
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Ocean topography off the coast of Newfoundland
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Ocean Currents
Ocean current:• A continuous, directional movement of ocean water
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Ocean Currents
2 Types of Ocean Currents...
1. Surface currents• Flow in the top 100-200 m
2. Deep currents• Flow below 200 m
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Surface Currents
Factors that influence surface currents are:
1.Wind
2.Earth rotation
3.Shape of the Earth’s continents
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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
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Ocean Currents
Local Ocean Currents...
1. Labrador Current (cold water)
2. Gulf Stream (warm water)• Refer to map p. 54
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Ocean Currents
Local Ocean Currents...
1. Labrador Current (cold water)
2. Gulf Stream (warm water)• Refer to map p. 54
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• 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
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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
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Ocean Waves
*Tsunamis
• giant waves caused by earthquakes, landslides or volcanic eruptions
• Can be very destructive .
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Tides
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.
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Tides
• Tides are caused by the gravitational pull of the moon and the spinning of the
Earth
• The moon exerts a greater force of pull than the sun due to its closer proximity to Earth.
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Tides
Tidal Range:• The difference in level between a high and a low tide
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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
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Tides2 Types of Tides:
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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
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Shaping our Shorelines
Wave energy is concentrated on headlands and spreads out as it reaches bays
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Shaping our Shorelines
Coastal erosion can lead to many shoreline features
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• Headlands
• Sea caves
• Sea Arches
• Sea Stacks
Shaping our Shorelines
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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
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Shaping our Shorelines
Wave energy is concentrated on headlands and spreads out as it reaches bays
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