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Ocean Water. Chapter 15. Section 1 Properties of Ocean Water. Objectives: List substances that are dissolved in ocean water Explain how a thermocline forms Compare and Contrast properties of ocean water Predict the solubility of salt in water at different temperatures.
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Ocean Water Chapter 15
Section 1 Properties of OceanWater • Objectives: • List substances that are dissolved in ocean water • Explain how a thermocline forms • Compare and Contrast properties of ocean water • Predict the solubility of salt in water at different temperatures
Skills Warm-up • What’s in Water? • Suppose that you have a glass of pure water, a glass of fresh water, and a glass of salt water. • If you evaporated the water, what would be left behind in each glass?
Origin of Ocean Water • When earth first formed, it was very ________ • Active volcanoes sent ________ ________and ___________ out • One of the gasses was _________________ • The released gasses gathered in a layer to become the __________________
Origin of Ocean Water • After earth’s surface cooled, the water vapor ________________ into droplets of water • Water droplets combined and fell to earth as _________ • Rainwater flowed over earth’s surface and formed _________ and __________ • Water then pooled in large connected basins – the _____________
Our Oceans • 4 Oceans • ___________ • ___________ • ___________ • ___________ • Pacific Ocean – largest ocean • covers ______ of the earth • contains _______ of earth’s salt water
Chemical Properties of Ocean Water • Ocean water is a mixture of dissolved • __________ • __________ • tiny amounts of many __________ • As rivers flow across earth, these substances are picked up • When rivers reach the ocean, the substances are deposited as _________ ______ or used by _______ _____________
Chemical Properties of Ocean Water • Major dissolved gasses • ________ ________ ____________ • Major dissolved salts
Salinity • The number of _______ __ ______ in 1 kg of water • Average salinity of ocean water is _________ • Salinity varies from one part of the ocean to another • What causes high salinity: • High _______________ • Low _______________ • ________________ • What causes low salinity: • High _______________ • Melting ____________ • Where fresh water meets salt water (___________)
Physical Properties of Ocean Water • _______________ • Top of water column directly heated by ______ – depth of 100 to 400 meters • Summer surface temps are _________ than winter • Temp varies from place to place – water is warmer near the __________ and cooler near the __________
Physical Properties of Ocean Water • Just beneath the surface water is a zone where water temp decreases rapidly - ______________ • Thermocline forms because warm surface water ______ __ ____ ___ colder water • Depth of thermocline changes with the __________ and with ___________ • Below the thermocline, water temp decreases only _____________
Ocean Water and Living Things • Organisms that live in the ocean use substances dissolved in ocean water to survive • _________ – use dissolved nitrate for growth • _____ __________– use calcium to build tough, thick shells • _________ – use silica to build tiny, intricate shells
Ocean Water and Living Things • Many organisms depend on __________ • For what???? • Sunlight can’t _______________ too far into ocean water • These organisms must live in _______ ________ near the shore or _________ on top of the water • Examples – algae and diatoms
Ocean Water and Living Things • Some organisms move up and down in the water column by changing their ________ • Fish have a _________ ____________ • Fill with gas from bloodstream – fish is less dense – fish rises • Empty swim bladder – fish is more dense – fish sinks deeper • Organisms that live in deep ocean water must withstand great _____________
Drinkable Ocean Water • You shouldn’t drink ocean water – it has too much _________ for your body to process • You will actually get more ___________! • Some areas of the world don’t have enough fresh water • They drink ocean water by removing the salt - ________________
Desalination • Ocean water is pumped into a chamber and __________ • Water turns to __________ • Steam is sent to another chamber where it cools and _____________ • Salt is too __________ and is left behind • Water from condensed steam is fresh and ________________ • But fossil fuels need to be used to heat the water
Check and Explain • 1. What substances are dissolved in ocean water? • 2. What is a thermocline? Explain how it forms. • 3. Explain the following properties of ocean water: composition, temperature, salinity, and density. • 4. Imagine you have a glass of water at room temperature. You mix salt into the water until no more will dissolve. Then you put the glass in the refrigerator. What will happen to the salt in the water?
Lab – “How Do Temperature and Salinity Affect Density?” • Text page 344
Section 2 Ocean Currents • Objectives: • Describe the major ocean current patterns in the Pacific and Atlantic oceans • Identify two factors that drive ocean currents • Compare and Contrast surface currents and deep currents • Predict the effects of the Coriolis force
Skills Warm-up • At the Edge • Imagine that you are riding in the center of a merry-go-round. • You want to throw a ball to a friend at the edge of the merry-go-round. • Where would your friend have to sit to be able to catch the ball?
Ocean Currents • If you were on a boat adrift in the ocean near Antarctica, the boat would travel in a _____________ direction. • It would be carried along in a flow of water called a ____________ • Current – a flow of water moving through the ocean • A strong current flows in a clockwise direction around _____________
Ocean Currents • Currents flow through all parts of the ocean • _______ __________ – flow horizontally at or near the top of the ocean • _______ __________ – flow horizontally far beneath the surface • Ocean water also flows _____________ • Ocean water can flow down toward the ocean floor or up toward the surface
Surface Currents • Surface currents are driven by _______ that blow for long distances over the ocean’s surface • The winds blow in a ________ ______ because of the Coriolis effect • __________ __________ – caused by the earth’s rotation, bends the earth’s winds and ocean currents
Surface Currents and Wind Patterns • Earth rotates in an ___________ direction • Earth’s motion makes winds blowing toward the equator curve ____________ • Winds blowing toward the poles curve ____________ • Surface currents in the ocean form similar patterns • If winds change direction, so do surface currents
Surface Currents in the World Ocean • ________ currents flow from the equator • ________ currents flow from the poles • Surface currents form a circular pattern called a ________ • Gyres in the northern hemisphere flow ________________ • Gyres in the southern hemisphere flow ________________
Deep Currents • The movement of surface currents has little effect on _______ ________ __________ • Deep currents are kept in motion by __________ differences • Cold water is the most dense and is at the ____________ • This deep cold water flows toward the ___________, but the Coriolis effect bends them ______________
Deep Currents • Where winds blow in a constant direction parallel to the coast, surface currents and deep currents can mix • Wind pushes warm surface water _______ _____ ____ ________ • ______ _______ _________ moves up to take its place • _____________– the upward movement of deep water • Upwelling brings ___________ up from the ocean floor – attracts marine animals
Shoreline Currents • Near shoreline, _______ currents form that travel only __________ ______________ • ____________ _________ – when waves approach the shore at an angle and create a zigzag pattern parallel to shore
Shoreline Currents • If there is a __________ or ___________, longshore currents can be trapped • Once it finds an opening, the longshore current breaks out forcefully • A narrow, powerful stream of water flows at a right angle to the shore – ______ __________ • Very _______________ – swim parallel to shore
Shoreline Currents • ____________ – forms when water carried to the shore in waves pulls __________ toward the ocean • Usually it is not strong enough to be dangerous • But, if wave action is _________ or ocean bottom _______ _________ sharply, it can pull swimmers out to deeper water
Upwelling and Fisheries • In areas of ___________, winds blow warm surface water away from the coast • Cold, deep water moves in to fill the space • This cold, deep water contains large amounts of _____________ that support _________ and feed _________ • These are the areas of the world’s most __________ fishing grounds
Upwelling and Fisheries • Usually the upwelling area along the ________ coast of S. A. is very productive • But, when ____ _________ comes, upwelling stops • El Nino is a disturbance of ocean currents and winds that occurs every _______ _______ • It warms coastal waters, not allowing the nutrient rich colder waters up • No nutrients – no fish!
Check and Explain • 1. Describe the surface currents in the North Pacific Ocean and the North Atlantic Ocean. • 2. What two factors cause ocean currents to form? • 3. How do surface currents and deep currents differ? How are they similar? • 4. What direction would a plane have to travel to reach a city directly south of its starting point if winds were blowing to the east? Why?
Section 3 Ocean Waves • Objectives: • Explain how waves form • Identify the parts of an ocean wave • Explain how to measure wave motion • Define how a water particle moves as a wave passes
Waves • Ocean waves form when _________ pushes against the ocean’s surface • _________ from the wind pushing makes ripples form • __________ is transferred from the wind to the water, making a wave • The _________ a wave surface becomes, the more energy it can absorb from the wind
Mechanics of Wave Motion • When you watch a wave move, the water appears to _______ __________ • But, the water barely moves at all • It is ______ ___________ that moves forward, not the water particles • Water particles actually move in a circular __________________ motion http://www.teachersdomain.org/ext/ess05_int_wavemotion/index.html
Characteristics of Waves • Ocean waves form _____ _______ ________ • Wind blows over open water causing unevenly space, ragged ______ ___ _________ to form • As the wave energy continues to travel, the waves form an even series of smooth, low hills of water called ____________