AY Honors/Oceans/Answer Key

Oceans

Skill Level

2

Year

2022

Version

26.12.2024

Approval authority

North American Division

1

Answer the following:

1a

What is an ocean?

An ocean is a continuous body of saltwater covering a large portion of the Earth.

1b

What is the difference between an ocean and a sea?

Seas are much smaller and shallower than oceans. Seas are partially enclosed by the land of one or more continents and usually connected to an ocean.

1c

What percentage of the Earth is covered in ocean?

71%

2

Complete the following regarding salinity:

2a

Define salinity.

The concentration of salt in a given volume of water.

2b

What is the salinity of the ocean?

The salinity of the ocean is, on average, around 35 parts per thousand(ppt). This means that for every liter of water there are 35 grams of salt.

2c

Mix a solution representing the salinity of the ocean. Take a drop of your solution and taste it.

Add 35 grams (2½ tablespoons) of salt to a beaker or bowl. Next, add 1000 grams (4 cups) of water (preferably tap water) to the beaker or bowl. Stir the mixture until the salt is completely dissolved in the water. When the salt is completely dissolved in the water you have seawater.

Lesson plan from the Surfing Scientist

i

Why does the salinity of the ocean make it less viable as potable water?

ii

Sprout seven beans in a container and another seven in another container. Water one with fresh water and the other with saltwater solution you have mixed. Evaluate the growth after seven days.

3

Label on a blank map the Pacific Ocean, Atlantic Ocean, Arctic Ocean, Indian Ocean, Southern Ocean, Mediterranean Sea, Chukchi Sea, Philippine Sea and the East China Sea. Which ocean is the largest? Which sea is the largest?

The Pacific Ocean is the largest ocean (approx. 60 million square miles). The Philippine Sea is the largest sea (approx. 2 million square miles).

4

Complete the following regarding ocean zones:

4a

Draw a cross section of the ocean and label the following oceanic zones: intertidal zone, neritic zone, oceanic zone, benthic zone, abyssal zone, pelagic zone, aphotic zone, photic zone and the continental shelf.

4b

Explain the difference between the photic zone and the aphotic zone.

The photic zone is the uppermost layer of the ocean. Here the sun can penetrate, allowing photosynthesis to occur. The aphotic zone is below the photic zone and receives little to no sunlight.

5

Complete the following regarding wind:

5a

Describe what causes wind.

Wind is caused by air flowing from a high pressure to a lower pressure.

5b

Explain what causes global wind patterns.

The differences in temperature between the equator and the poles and the rotation of the earth. At the equator the sun warms the air more than any other place causing the air to rise and flow towards the poles. The colder, denser air moves towards the equator at the same time to replace the heated air.

5c

Define the Coriolis Effect.

When the rotation of the earth causes the winds in the northern hemisphere to appear to be curving to the right and the winds in the southern hemisphere to appear to curve to the left.

5d

Label the following wind currents on a diagram of the globe: polar easterlies, westerlies, trade winds, and doldrums. Identify the wind currents in the hemisphere where you live.

Polar Easterlies: Dry, cold winds that originate at the poles and flow to the subpolar regions where the pressure is lower.

Westerlies: Come from the west at midlatitudes and are sustained by polar easterlies. They are strongest in the winter when the pressure at the poles is low.

Trade Winds: Strong winds that blow east across the tropics. These winds are very predictable. Most tropical storms originate as a trade wind.

Doldrums: The place where the trade winds from both hemispheres meet (the intertropical convergence zone). The winds here are very weak to nonexistent and the weather is usually calm.

6

Complete the following about tides:

6a

What causes tides?

The gravitational pull of the sun or the moon.

6b

Describe the following types of tides: neap tides, spring tides, high tide, and low tide.

Neap tides: Occur when the gravitational pulls from the sun and moon are working against each other causing a weak tide. Neap tides occur at quarter moons.

Spring tides: Occur when the gravitational pulls from the sun and moon are reinforcing each other causing a strong tide. Spring tides occur during full and new moons.

High tide: The moon’s gravitational pull causes the water to bulge on the side closest to the moon. These bulges are high tide.

Low tide: The oceans on the other side from the moon’s gravitational pull experiences low tide.

6c

What dangers do tides present?

7

Complete the following about ocean currents:

7a

What are surface currents?

Surface currents occur at 328 feet deep or above. They are driven primarily by winds. There are two different types of surface currents. These are coastal currents and surface ocean currents.

Coastal currents are divided into different types as well. Longshore currents, rip currents, upwelling and downwelling are all coastal currents because they are all driven by local or coastal winds and typically occur near the shoreline. Longshore currents occur when a wave hits the beach at an angle instead of head on. Part of the wave’s energy runs parallel to the shore creating the longshore current. Barrier Islands and land formations called spits are formed by these currents. Rip currents are caused when underwater land formations block the waves from flowing directly back to the ocean. When the waves that have already crashed flow through a narrow passage it creates a lot of force and creates a rip current. Upwelling and downwelling occur when the wind blows the surface water away causing the deeper water to replace it or the opposite when the wind blows the surface water towards a barrier and the force of the wind causes it to sink. These currents are important to the cycling of nutrients, oxygen, and other gasses in the ocean. Surface oceans currents are driven by global wind patterns.

7b

What are deep ocean currents?

Deep ocean currents (the global conveyor belt) are driven by the density of the water. The more salt in the water the denser it becomes. When water freezes at the poles it leaves the salt behind creating a large amount of dense, cold water that eventually sinks allowing more water to replace it. This causes a current that eventually goes around the entire world.

These deep-water currents move a lot slower than surface currents, about a few centimeters per second. The deep-water currents distribute nutrients and help regulate temperatures. Some ocean animals use these currents to migrate.

7c

What is a rip current? How can you survive being caught in a rip current?

When the rotation of the earth causes the winds in the northern hemisphere to appear to be curving to the right and the winds in the southern hemisphere to appear to curve to the left.

7d

On a blank world map, sketch the global conveyor belt.

i. Use a blue writing utensil to represent the cold dense currents.

ii. Use a red writing utensil to represent the warm less dense currents.

iii. Label the oceans that the global conveyor belt passes through.

The global conveyor belt on a continuous-ocean map (animation)

The current begins near the North Pole getting warmer as it travels south around South America eventually coming to Antarctica where it picks up cold water again. It then splits, one part traveling to the Indian Ocean and the other to the Pacific Ocean. As these currents reach the equator, they get warmer and eventually make their way back around South America and up in the North Atlantic Ocean where the cycle starts again. The water moves quite slowly at about 10 cm per second. It can take up to 1000 years for water in the North Atlantic to end up in the North Pacific!

7e

Conduct an experiment of your choosing that demonstrates how the global conveyor belt works.

Materials Needed:

• Pyrex® baking dish, 2-qt. or 1.5-qt. in size.
  • Alternatively, other similarly sized, heat-resistant glass baking ware that can safely withstand the hot temperatures of being placed just above a flame for several minutes could be used instead.
• Thyme, dried (2 tsp.)
  • Alternatively, any other dried leaf spice could be used.
• Teaspoon
• Vegetable oil (about 4 cups)
• Measuring cup
• Spoon
• Ceramic coffee mugs (2). These should be equal in height.
• Small candles or cans of Sterno® (4). These should be much shorter than the coffee mugs so that the flame does not get too close to the bottom of the glass baking dish.
• Lighter or matches
• Thermometer
• Notebook/Pencil or Pen

Experiment:

1. On a surface that is safe to spill some vegetable oil, fill the baking dish about half to three-quarters full of vegetable oil. (Depending on the exact size of baking dish you are using, this may be about 4 cups of vegetable oil or less.)
2. Mix the 2 teaspoons of thyme in with the vegetable oil in the baking dish. Stir thoroughly to distribute the flakes of thyme. The flakes of thyme will flow with the liquid, showing the direction and velocity of any fluid flow.
3. Place the baking dish on top of the two ceramic mugs.
4. Observe the oil and spice mixture. With no heat (energy) being added to the system, there should be little or no movement of the liquid, once it has settled.
5. Place a candle underneath the baking dish, directly in the middle. Make sure the mugs still stably support the baking dish.
6. Light the candle and let the liquid heat up for at least one minute. Your setup should look like the picture below. You can also use a can of Sterno instead of a candle. Sterno cans produce more heat than candles do.
7. As the oil heats and begins to flow, observe the pattern of fluid flow (circulation) by noting the location of individual flakes of thyme over time. Write down all of your observations in your lab notebook. This type of energy movement is called thermal convection, because added heat causes the fluid flow (circulation by convection) by lowering the density of the liquid.
8. Be sure to view the model several times during the experiment, both from above the dish and from the side of the dish.
9. Draw a sketch of the circulation in your lab notebook.
10. Measure the temperature of the oil in different parts of the model.
11. What is the biggest temperature difference you can find?
12. Record the temperature in your notebook.

7f

What are tidal currents?

Tidal currents are caused by tides. They are a horizontal movement that accompanies a rise and fall in the water level caused by a tide. The two different types of tidal currents are: flood current and ebb current.

Flood current: Occurs when the tide is rising, and the current is going towards the shore.

Ebb current: Occurs when the tide is falling, and the current is going to back towards the ocean.

7g

Explain why the part of the ocean along western Europe is warmer than other areas at the same latitude.

In the Atlantic Ocean there is a strong current called the Gulf Stream. The Gulf Stream carries warm water from the Gulf of Mexico to western Europe. This makes western Europe much warmer than other places at the same latitude.

8

How do oceans affect humans since we live on land?

Weather: The evaporation of ocean water causes an increase in humidity and temperature in the surrounding land. This evaporation leads to the making of clouds in the atmosphere which can bring rain and storms. These clouds can be blown long distances by winds (nearly all rain originates from the ocean).

Temperature: Most of the heat from the sun is stored in the ocean. The heat is then distributed around the earth helping to regulate the earth’s temperature.

Breathing: More than half of the oxygen we breathe comes from photo-synthesizers in the ocean such as algae, kelp, and phytoplankton.

9

Complete the following regarding threats to the oceans:

9a

Brainstorm a list of at least five of the greatest threats to our oceans. Compare your list with another reliable source.

• Climate change/global warming
• Plastic pollution
• Overfishing
• Acidification
• Habitat destruction

9b

Research the cause of each of these threats and list 10 actions you can take to help.

1. Conserve water – less wastewater and runoff go into the ocean.
2. Reduce pollutants – choose nontoxic chemicals and dispose of them properly
3. Reduce waste – cut down on what you throw away by reusing and recycling
4. Cut down on the amount of plastic you use and purchase – use reusable bags, water bottles etc.
5. Use energy efficient light bulbs – using less electricity means less pollution
6. Turn down your thermostat – the less fossil fuels and electricity used means less carbon in the air (extra carbon in the air traps too much heat causing greenhouse gas emissions)
7. Fish responsibly – “catch and release,” only fish in areas where it is allowed, only catch what you need
8. Practice safe boating – follow “no wake” zones, anchor your boat away from coral reefs and sea grasses
9. Pick up trash around beaches and your community
10. Reduce vehicle emissions – ride your bike, walk, carpool, use fuel efficient vehicles.

9c

Write a plan for how you are going to act on one of your ideas. Implement your plan and report back to your instructor.

10

Be able to identify at least two organisms from each kingdom (Animal, Plant, Fungi, Bacteria, Archaea, and Algae) that live in the ocean.

Animal:

• 

  Bottlenose Dolphin

• 

  Sea Krait

Plant:

• 

  Turtlegrass

• 

  Eel Grass

Fungi:

• 

  Marine fungi

• 

  The shell of this sea snail, Littoraria irrorata, is covered with the lichen Pyrenocollema halodytes

Bacteria:

• 

  Nostoc

• 

  Sea Sawdust

Archaea:

• 

  Picoplankton

• 

  Halophiles

Algae:

• 

  Bladder Wrack

• 

  Sea Lettuce

11

Do one of the following:

11a

Tell a Bible story that involves an ocean (or sea).

Some examples include: The crossing of the Red Sea (Exodus 14), Jonah and the Whale (Jonah 1-3), and Jesus calms the storm (Matthew 8, Mark 4, and Luke 8)

11b

Write a song or poem comparing an aspect that you learned about oceans with a spiritual lesson.

11c

Memorize two Bible verses pertaining to oceans (or seas).

Psalm 89:9, Micah 7:19, Psalm 93:4, Psalm 104:25-26

12

Do at least two of the following activities:

12a

Watch a video about oceans or the organisms that live in the ocean.

12b

Visit a zoo or aquarium that has an ocean exhibit. Think about which oceanic zones the creatures you see would live in.

12c

Put together a short video or slide presentation about what others are doing to help protect the oceans and its inhabitants from pollution. Include a few of your own ideas for helping the oceans.

12d

Draw or paint a picture of something that you enjoyed learning while studying about oceans.

12e

Visit an ocean or sea. Observe what you have studied regarding tides, currents, wind and wildlife.

References