OCEANOGRAPHY - Stemnova...Lecture Transcript (Core Curriculum) Plate Tectonics We tend to think of...

v vOCEANOGRAPHYTEACHER GUIDE AND CURRICULUM HANDBOOK

CREATED BY: ISHA SANGHVI | ALICE MA | RYAN LEE

v vEPIDEMIOLOGYTEACHER GUIDE AND CURRICULUM HANDBOOKStemnova is a 501(c)(3) nonprofit founded in California with the mission to increase educational equity across the community. Our fundamental belief is that every child is deserving of a hands-on, experimental, enriching curriculum to help immerse them into the vast field of STEM. Stemnova has volunteered at local elementary schools and low-income housing centers, mentored middle school budding Science OlympiadTM teams, hosted science competitions drawing students from all across the state of California, and created an open-source curriculum to ensure our mission of educational equity will be achieved. With this curriculum, we hope teachers will be empowered with ample resources to inspire the next generation of scientists.

The teaching guide is filled with lesson transcripts that coincide with corresponding presentations for teachers to use with their students. The lesson transcript has been perfected after years of actual implementation in classrooms and schools. This handbook is also filled with activities, experiments, and worksheets to ensure that students are able to apply the knowledge learnt in lessons into actual real-world simulations.

The following curriculum guide is for Epidemiology or the study of diseases. Students will be exposed to the different types of diseases, the biological and environmental causes of epidemics, the functions of the immune system, statistical measures scientists use themselves to analyze epidemics, and current experimental solutions to some of the world’s biggest diseases. Not only will students be able to intertwine math and biology into one subject, they will also be able to better understand the world around them.

We thank you for your vested interest in sparking a love for science in the next generation.

v v

For more information about Stemnova, please check out our website: stemnova.education. At Stemnova, we believe it takes a community to create change, and we hope you join our community of dedicated students, educators, and leaders hoping to spread love and opportunity for STEM to students everywhere.

https://stemnova.weebly.com/

Lesson 1 Geology

Summary

1. Subject(s): Plate tectonics, Wilson cycle, where land meets sea, types of sediment

2. Topic or Unit of Study: Oceanography

3. Grade/Level: 4-6 grades

4. Objective: Students should learn a basic understanding of geology associated

with oceanography.

Key Skills: Students should be able to explain plate tectonics, the Wilson cycle, the

way that land and sea meet, and types of sediment.

5. Time Allotment: 2-3 hours

Powerpoint

Core Curriculum:

https://docs.google.com/presentation/d/1IDSokU09nyt8kebInwSv-Nk2_vAwAMJa_GJZZ1QrHAg/

edit?usp=sharing

Supplement Curriculum:

https://docs.google.com/presentation/d/1zujUzeJdPxl5HGXM5C2k0tCsAeP9sh1-KUf6-ALZ7oE/ed

it?usp=sharing

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives

4.0 International License .

https://docs.google.com/presentation/d/1IDSokU09nyt8kebInwSv-Nk2_vAwAMJa_GJZZ1QrHAg/edit?usp=sharing

https://docs.google.com/presentation/d/1IDSokU09nyt8kebInwSv-Nk2_vAwAMJa_GJZZ1QrHAg/edit?usp=sharing

https://docs.google.com/presentation/d/1zujUzeJdPxl5HGXM5C2k0tCsAeP9sh1-KUf6-ALZ7oE/edit?usp=sharing

https://docs.google.com/presentation/d/1zujUzeJdPxl5HGXM5C2k0tCsAeP9sh1-KUf6-ALZ7oE/edit?usp=sharing

http://creativecommons.org/licenses/by-nc-nd/4.0/


Lecture Transcript (Core Curriculum)

Plate Tectonics

We tend to think of land on Earth as being fixed and unmoving, however, the land does move.

The movement is very, very slow, only about 1 to 5 inches per year. It takes over millions of years

for the movement to be noticable.

The part of the land that moves is called the lithosphere. The lithosphere is made up of the

Earth’s crust and a little more further down into the Earth. The lithosphere moves in big chunks

called plate tectonics. The plate tectonics are a little bit like giant puzzle pieces. There are 2

types of plates, continental and oceanic plates. Continental plates are the ones that form

continents, like the African Plate, Australian Plate, and South American Plate. Oceanic plates are

beneath oceans, like the Pacific Plate. The main difference between these 2 types of plates that

you need to know is that oceanic plates are denser.

There are three types of movements that the plates experience — convergent, divergent, and

transform.

Convergent

In the convergent type of plate movement, the plates move towards one another and give rise to

geographical structures like mountain ranges and volcanoes.

India and Asia collided into each other about 55 million years ago, which led to the formation of

the Himalayas, the highest mountain range on the earth.

Similarly, when the oceanic plates crash into each other deep trenches like the Mariana Trench in

the North Pacific Ocean and underwater volcanoes are formed.

Divergent





In the divergent type of plate movement, the plates move apart.

The magma from the interior of the Earth surges toward the surface and pushes the tectonic

plates away from each other. Between oceanic plates, divergent boundaries are called

mid-ocean ridges. Between continental plates, divergent boundaries are called rift valleys.

One famous mid-ocean ridge is the Atlantic Mid-Ocean Ridge. This is the longest divergent

boundary in the world at 10,000 miles and occurs where the North and South American Plates

are moving away from the Eurasian and African Plates. Along this ridge, there are many

volcanoes and earthquake epicenters.

Additionally, scientists believe that millions of years from now, Eastern Africa will split apart from

the continent and form a new landmass. This divergent boundary is called the East African Rift

Valley, and it is one of the most volcanically active places in the world.

Transform

In the transform type of plate movement, two plates move sideways with respect to each other.

When the two plates rub against each other, a lot of energy is built up, and this energy is

sometimes released as earthquakes.

These movements do not produce spectacular geographical features like mountains or

oceans

Hotspots

Very different from the boundaries mentioned above, hotspots are found in the middle of

tectonic plates. Hotspots are regions where a lot of magma is rising to the surface, and

this magma often breaks through the plate, leading to volcanoes. A great example is

Yellowstone National Park. Right in the middle of the United States, Yellowstone National

Park is nowhere near a plate boundary, but there are still many signs of volcanic activity,

geysers, hot springs, minor earthquakes, and a humongous volcanic crater. This is





because right below Yellowstone is a column of magma rising to the surface. This magma

brings heat and may eventually poke through.

The Wilson Cycle

The Wilson cycle is the cyclical opening and closing of ocean basins caused by movement of the

Earth’s plates. The Wilson cycle begins with a rising plume of magma and the thinning of the

overlying crust. As the crust continues to thin due to extensional tectonic forces, an ocean basin

forms and sediments accumulate along its margins. Subsequently subduction is initiated on one

of the ocean basin’s margins and the ocean basin closes up. When the crust begins to thin again,

another cycle begins.

The Wilson cycle comes in four stages:

Stage A — begins with a stable continental craton. A craton is a part of the lithosphere that is old

and stable. A hot spot rises up under the craton, heating it, causing it to swell upward, stretch and

thin like taffy, crack, and finally split into two pieces. This process not only splits a continent in

two it also creates a new divergent plate boundary.

Stage B – the one continent has been separated into two continents, east and west, and a new

ocean basin is generated between them. As the ocean basin widens the stretched and thinned

edges where the two continents used to be joined cool, become denser, and sink below sea

level. Wedges of divergent continental margins sediments accumulate on both new continental

edges.

Stage C – the ocean basin widens, sometimes to thousands of miles; this is comparable to the

Atlantic ocean today. As long as the ocean basin is opening we are still in the opening phase of

the Wilson cycle.





Stage D – the closing phase of the Wilson Cycle begins when a subduction zone (new

convergent plate boundary) forms. The subduction zone may form anywhere in the ocean basin,

and may face in any direction.Once the subduction zone is active the ocean basin is doomed; it

will all eventually subduct and disappear.

Types of Sediment

There are three types of sediment — clastic, chemical, and biochemical sediments.

Clastic

Clastic sediments are composed of fragments or grains (or clasts) of other rocks and minerals.

We classify clastic sediments based on their grain size. Grain Size reflects the amount of bumping

and grinding that has occurred. For example, the largest clasts are generally found close to the

source of the sediment, since they are harder to transport. The farther away you go from the

source, the more grinding occurs between the clasts, and they become smaller and smoother

from the transportation process.

Chemical

Chemical sediments are not formed from the weathering and erosion of other rocks. They form

from the precipitation of minerals out of a solution. Most commonly, the solution is sea water, and

the precipitates are called evaporites.

Biochemical

At the end of the Cambrian era, marine organisms obtained the ability to form protective shells.

When these organisms die, their shells fall to the sea floor forming biochemical sediment. Much

of this material comes from microorganisms (organisms of microscopic size). The primary

biochemical rock is limestone. If the shells are not ground finely, the material may be called

bioclastic.





Lesson Transcript (Supplement Curriculum)

The Rock Cycle

The rock cycle is a series of changes that circle around three types of rocks — igneous,

sedimentary, and metamorphic. These three types of rocks can change into one another through

the processes of the rock cycle. Before we jump into the specifics, let’s actually examine what the

three types of rocks are.

Igneous Rock

Igneous rock is formed from magma. Magma is lava that has come out of a volcano, it is an

extremely hot liquid that is made out of melted minerals. When magma cools, it forms igneous

rocks. Igneous rock can form above or below ground. Above ground, the magma cools very

quickly or suddenly, such as when it touches water. However, underground, the magma will cool

much slower. Igneous rocks that form from magma cooling above ground are called extrusive

rocks; igneous rocks that form from magma cooling below ground are called intrusive rocks.

Sedimentary Rock

Sedimentary rock is formed when sediments, small tiny pieces of rock, are packed together. Over

time, these sediments become cemented together and create sedimentary rock. If you look at

the picture at the left of conglomerate, a type of sedimentary rock, you can actually see the

smaller rock pieces packed together.

Metamorphic Rock

Metamorphic rock forms when rocks are heated to extremely high temperatures. When rocks

become buried deep underground, the temperature is very very high. The high temperature will

cause the rock to form crystals and become metamorphic rock. If you look at the picture at the

left, you will see that the rock has neat stripes across from left to right. If you see these stripes, it’s

usually a sign the rock is metamorphic since high pressures cause these patterns to form.





How Does One Type of Rock Change Into A Different Type?

Igneous or sedimentary rock can change into metamorphic rock if they undergo extreme heat

and pressure underground. To get to igneous rock, both sedimentary rocks and metamorphic

rocks can be melted into magma. This magma then cools underground or above ground and

forms igneous rock. To get to sedimentary rock, both igneous rocks and metamorphic rocks can

be eroded into smaller pieces called sediments by wind, water, plants, and other natural forces.

Over time, these small sediments are packed together and cement to form new sedimentary

rock.

Dating Rocks

Today, scientists have plenty of ways to determine the ages of rock layers and fossils. There are

two general categories of rock and fossil dating - relative dating and absolute dating.

Relative Dating

Geological Principles

In relative dating, the general age of a rock layer or fossil is determined. Relative dating is the

method used most often to date fossils. One key principle to remember is the Law of

Superposition. This law basically states that in undisturbed rock layers, younger rock layers are

always on top of older ones. Sounds pretty obvious right? Based on the picture and the Law of

Superposition, one can safely assume that the yellow, lighter rock layers on top are older than

the redder rock layers on the bottom.

Relative Dating: The Process & Multiple Index Fossils

Simply put, relative dating is a method that compares a unknown rock layer or fossil’s age with

one that scientists already know. Scientists use index fossils to help determine the time frame of

other fossils and rock layers. Index fossils are fossils that are only known to occur in a certain

time period.

Now, relative dating can be used to date fossils or rock layers. For example, let’s say you have a

layer of sandstone you are trying to figure out the age of. In the layer of sandstone, you find a





specific tree fossil, and you know that species of tree lived 3 million years ago. Based on this

information, you can probably guess safely that the mysterious sandstone is approximately 3

million years old. Here’s another example. Let’s say you discover a mysterious insect fossil in

clay. Based on previous studies, you know the clay is 20 million years old, so thus, the insect is

also probably around 20 million years old.

Sometimes multiple index fossils can be used. In a hypothetical example, a rock formation

contains fossils of a type of brachiopod known to occur between 410 and 420 million years. The

same rock formation also contains a type of trilobite that was known to live 415 to 425 million

years ago. Since the rock formation contains both types of fossils the ago of the rock formation

must be in the overlapping date range of 415 to 420 million years.

Absolute Dating

Half Life

Before we jump into absolute dating, it is important to understand the concept of the half life.

Essentially, as time passes, radioactive elements such as Uranium or Carbon-14 (a type of

carbon), break down into simpler elements through a process called radioactive decay. The

half-life of a radioactive element is the time it takes for half of the substance to decay. For

example, let’s say you have 100 grams of Element A, and you know Element A’s half-life is 500

years. That means that after 500 years, you will only have 50 grams of Element A. A more

realistic example is Carbon-14. Carbon-14 slowly decays into Nitrogen-14, a simpler element, and

its half-life is 5700 years. This means that if you have 100 grams of Carbon-14, after 5700 years,

you will only have 50 grams left.

Absolute Dating

Absolute dating uses radioactive dating to determine the exact time period of a fossil. It uses

radioactive materials, like elements we mentioned before, found in the fossil as a geological

clock. Again, certain radioactive elements leave traces of themselves over time and will decay

over time. By seeing how much of the element is remaining and how much has decayed to a

different element, scientists can determine the exact time period of a fossil.





For example, we already know Carbon-14 decays into Nitrogen-14 over 5700 years. If I take an

old tree fossil and discover there are 2 grams of Carbon-14 and 2 grams of Nitrogen-14, I know

the ratio of Carbon to Nitrogen is 1 to 1. This means that half the total amount of substance is

Carbon and the other half is Nitrogen. Because I know Carbon-14’s half-life is 5700 years, this 1 to

1 ratio tells me the tree fossil is most likely 5700 years old. (Teacher’s Note: To better illustrate

this example, it might be best to draw a diagram on the board or utilize the slide as a visual

reference.)

Activity

Modeling Plate Tectonics

Teaching Note: The purpose of this activity is to give students a better conceptual

understanding of the structure of the Earth. Using common food items, students will

create a model of the Earth’s surface and then enjoy their masterpiece after.

Materials Needed: Different colored candies (M&Ms), crackers, white frosting (dye red if

possible), paper plates, plastic knives, marshmallows, and chocolate frosting/Nutella

1. To conserve materials, organize the students into pairs or groups of three. Each

group needs one paper plate, one spoonful of chocolate frosting, one spoonful of

vanilla frosting, a pack of M&Ms, one marshmallow, two graham crackers, and two

plastic knives.

2. Read the following prompt aloud: “You are a geologist hired by the kingdom of

Candyland to better understand the planet’s geography. Candyland has a very

similar structure to Earth except everything is edible. Use the following pieces of

information to construct a model of Planet Candyland”

3. Have each group spread the white frosting across the plate. Ask them what layer

of the planet the frosting represents and why? - Sample Answer: The frosting

represents the mantle beneath the crust. Like the mantle, the frosting is not rigid,

able to move around, and sticky.





4. Have each group break the crackers into at least four pieces and lay them on top

of the frosting; two of the crackers should be spread with brown frosting. Let the

students know that each of the cracker pieces represent a plate, and ask them

what they the frosted crackers represent and why? - Sample Answer: The brown

crackers are oceanic plates since they are heavier and denser that the

non-frosted ones.

5. Have each group identify convergent, divergent, and transform boundaries - this

can be up to their choice. Students should line convergent boundaries with blue

candies, transform boundaries with yellow candies, and divergent boundaries with

red candies. Ask them, “Is it possible for a boundary between a frosted and

non-frosted cracker to be lined with red or yellow candies?” - Sample Answer: No;

because the oceanic plate is denser, it always sinks beneath the continental one,

creating a convergent boundary that should be lined with blue candies.

6. Read the following aloud: “Now we have the basic map of Planet Candyland.

However, we just got new data that there is a hotspot beneath one of the oceanic

plates.” Ask the students what a hotspot is, and have them represent the hotspot

with one marshmallow passed out.

7. With the orange M&Ms, have the students map out where they think volcanoes

should be. There should be orange candies near the marshmallow and along the

convergent and divergent boundaries. Ask them why there shouldn’t be

volcanoes allow the yellow transform boundaries and why there are volcanoes

near the hotspot.

8. Now, assign the following words to each group: friction, earthquakes and

tsunamis, land formation, and the Wilson Cycle. Groups should present their plates

and explain how the term they’ve been assigned relates to their map.





Lesson 2 Ocean Movements

Summary

1. Subject(s): Ocean temperature, salinity, and density



4. Objective: Students will learn about factors of temperature, salinity, and density in

the ocean

Key Skills: Students should be able to explain the ocean in relation to temperature,

salinity, and density.


Powerpoint

https://docs.google.com/presentation/d/18XFUJ53k8AE1MpdMKJ-EMlKrKf9Btewg5qpgkKkKvz8/e

dit?usp=sharing

Lecture Transcript

Ocean Movements

The ocean is not a uniform body of water. The ocean is made up of many water masses that flow past each other. These distinct masses of water each have a characteristic density. Density is the relative heaviness of a substance; it is mass per unit volume. Dense water masses will sink while



https://docs.google.com/presentation/d/18XFUJ53k8AE1MpdMKJ-EMlKrKf9Btewg5qpgkKkKvz8/edit?usp=sharing

https://docs.google.com/presentation/d/18XFUJ53k8AE1MpdMKJ-EMlKrKf9Btewg5qpgkKkKvz8/edit?usp=sharing



less dense ones will float above them. It is similar to density differences that lead to oil floating on top of water in a bottle of salad dressing. Water masses of different densities will similarly layer out. This layering is known as stratification in the ocean. There is no single perfect example of a "typical" stratification, though the link below is a neat graphic.

Density

Density of seawater is primarily determined by two factors: temperature and salinity. Warmer water is less dense than colder water. Therefore, warm water floats near the surface while cold water will sink toward the bottom. Salinity also affects density. Higher salinity (more salts in the water) leads to higher density. So salty water sinks while fresh water floats at the surface.

Anywhere in the ocean where water masses of different salinity and/or different temperature meet, the ocean will be stratified. There will be distinct layers of water found at different depths. The layer of the ocean where density increases the fastest is called the pycnocline.

Temperature

The major source of heat for the ocean is the sun. Therefore, it is only surface waters that get heated. Deep-ocean water is cold with temperatures hovering around 40C. The sun does not heat the surface of the ocean evenly. Polar regions receive very little, diffuse sunlight and even surface waters are cold there. Therefore the entire column of water from the surface to the bottom is cold; there is no thermal stratification. Tropical regions receive the most solar energy and tropical surface waters are warm. The warmer surface waters, with their low density, float on top of the colder deep water and the ocean is thermally stratified in the tropics. Temperate surface waters are cold in the winter but warm up in the spring and summer. Therefore, in these regions, there is no thermal stratification in the winter. It builds up as the seasons change and there is strong stratification in the summer months.

Plotting the change in temperature with depth, in the tropics for example, clearly shows that temperature does not just decrease uniformly with depth. Instead, there are three distinct layers or zones. The warm upper zone, known as the mixed or surface zone, is kept uniformly warm as waves and currents distribute the solar energy from the sun. The middle zone is a region where temperature decreases with depth; this is known as a thermocline. Within the thermocline, warm surface water mixes with cold deeper water. Below the thermocline is the deep layer, which is uniformly cold.





Salinity

Salinity is a measure of the total amount of dissolved solids (salts) in the ocean. The average salinity in the ocean varies from about 33 – 37 parts per thousand (ppt or o/oo). Salinity can approach 0 (fresh water) where rivers enter the ocean and may be very high in areas where there is little rain and an excess of evaporation. The amount of rainfall, input from rivers and streams and the level of evaporation will all affect the salinity of the ocean in any area. Therefore, most salinity variation take place near the surface where these environmental influences occur.

Diffusion is the slow mixing that occurs due to random motion of molecules. The salts and water molecules in seawater are vibrating and this vibration causes them to bounce off each other and mix. Salts will slowly spread away from areas of high salinity and toward areas of low salinity due to diffusion and the salinity of those areas will change.

The salts dissolved in seawater are heavier than the water molecules themselves. Therefore increasing the salinity of water increases its density. Water with low salinity will float on top of water with a high salinity, as happens when river water flows into the ocean. Salinity, as temperature, does not increase uniformly with depth. A plot of salinity versus depth shows three distinct zones. The upper mixed zone is characterized by lower salinity. The middle zone is a zone where salinity increases with depth; this is known as a halocline. Below the halocline, the deep zone contains water of fairly uniform higher salinity.

Activity

Density Demonstration

Teaching Note: The purpose of this demonstration is to show how water masses of

differing densities interact with each other. Students will also receive a more in-depth look

of the thermocline.

Materials Needed: two 500-600 mL beakers per group (any large glass container works

as well as long as it is transparent), sea salt (NaCl), Epsom salt (MgSO4), hot water, cold

water, room temperature water, red food coloring, blue food coloring, one sheet of binder

paper per group, one thermometer per group





Demonstration 1: Freshwater and Saltwater

1. Distribute two beakers to each group. In both beakers, pour room temperature

water. Dissolve sea salt and add blue food coloring to one of the beakers.

2. Have the students combine the contents of the two beakers and record their

observations on the binder paper.

3. Give the students 5 minutes to discuss and write down where this phenomenon

may occur - Sample Answer: Sea ice melting, rainfall, and river runoff all lead to

situations in which freshwater interacts with salt water.

Teaching Note: Between demonstrations, it is suggested to rinse the beakers of coloring.

Demonstration 2: Saltwater and Saltwater

1. Distribute two beakers to each group. In both beakers, pour room temperature

water. Dissolve sea salt in one and add blue food coloring. Dissolve Epsom salt in

the other and add red food coloring.

2. Have the students combine the contents of the two beakers and record their

observations on the binder paper.

3. Give the students 7 minutes to discuss and write down why this phenomenon

occurs and where this phenomenon may occur - Sample Answer: Epsom salt is

heavier than sea salt; thus, water with dissolved Epsom salt is denser and sinks to

the bottom. This may occur near underwater volcanoes that eject denser salts

and minerals into the ocean.

Demonstration 3: Warm Water and Cold Water

1. Distribute two beakers to each group. In one beaker, pour the cold water and dye

it blue. In the other beaker, pour the warm water and dye it red.

2. In the cold water beaker, have the students measure the temperature per

centimeter above the table. Plot this data in a table similar to the one below:

Centimeters from Bottom of Temperature of Water Layer





Beaker

1 cm X degrees Celsius

2 cm Y degrees Celsius

... ...

3. Slowly add the warm water to the cold water beaker. Every centimeter of water

increase, remind the students to record the temperature and plot the data in the

data table on the binder paper.

4. When all the warm water has been added, record observations on the paper as

well as the water surface temperature.

5. Give the students ten minutes to plot the data from the table on a chart. The X-axis

should be Centimeters from Bottom of Beaker while the Y-axis is Temperature of

Water Layer. Afterwards, have the students circle the thermocline based on the

graph. If there is no visible thermocline, have students discuss and record 2

reasons why the experiment does not accurately represent what happens in the

oceans - Sample Answer: Ocean water masses are larger & this demonstration

does not account for salinity of water





Lesson 3 Ocean Currents

Summary

1. Subject(s): thermohaline circulation, surface and coastal currents, and tides



4. Objective: Students will learn about ocean currents, including thermohaline

circulation, surface currents, coastal currents, and tides

Key Skills: Students should be able to explain the differences between surface

and coastal currents, explain tides, and briefly explain thermohaline circulation.


Powerpoint

https://docs.google.com/presentation/d/1mVMzADn93rJiExvX7VYOTMyiWS9K0fk4KBY7A5cTo4o

/edit?usp=sharing

Lecture Transcript Thermohaline Circulation (Slides 2,3,4)

Winds drive ocean currents in the upper 100 meters of the ocean’s surface. However, ocean

currents also flow thousands of meters below the surface. These deep-ocean currents are driven

by differences in the water’s density, which is controlled by temperature (thermo) and salinity



https://docs.google.com/presentation/d/1mVMzADn93rJiExvX7VYOTMyiWS9K0fk4KBY7A5cTo4o/edit?usp=sharing

https://docs.google.com/presentation/d/1mVMzADn93rJiExvX7VYOTMyiWS9K0fk4KBY7A5cTo4o/edit?usp=sharing



(haline). This process is known as thermohaline circulation.

In the Earth's polar regions ocean water gets very cold, forming sea ice. As a consequence the

surrounding seawater gets saltier, because when sea ice forms, the salt is left behind. As the

seawater gets saltier, its density increases, and it starts to sink. Surface water is pulled in to

replace the sinking water, which in turn eventually becomes cold and salty enough to sink. This

initiates the deep-ocean currents driving the global conveyor belt.

Surface Currents (Slides 5,6,7)

The water at the ocean surface is moved primarily by winds that blow in certain patterns.

Surface ocean currents flow in a regular pattern, but they are not all the same. Some currents are

deep and narrow. Other currents are shallow and wide. Currents are often affected by the shape

of the ocean floor. Some move quickly while others move more slowly. A current can also change

somewhat in depth and speed over time. Surface currents form large circular systems called

gyres.

Surface ocean currents carry heat from place to place in the Earth system. This affects regional

climates. The Sun warms water at the equator more than it does at the high latitude polar regions.

The heat travels in surface currents to higher latitudes. A current that brings warmth into a high

latitude region will make that region’s climate less chilly.

Tides (Slides 8,9,10)

Tides are actually waves, the biggest waves on the planet, and they cause the sea to rise and fall

along the shore around the world. Tides exist thanks to the gravitational pull of the moon and the

sun, but vary depending on where the moon and sun are in relation to the ocean as the earth

rotates on its axis. The moon and sun’s pull cause two bulges or high tides in the ocean on

opposite sides of the earth. The moon, being so much closer, has more power to pull the tides

than the sun and therefore is the primary force creating the tides.

However, when the sun and moon reinforce each other’s gravitational pulls, they create

larger-than-normal tides called spring tides. The opposite of this—when the gravitational forces of





the sun and moon pull from opposite sides of the earth and cancel each other out—is called a

neap tide and results in a smaller-than-usual tidal range.

Coastal Currents (Slide 11,12,13,14)

Along the coast, there are also different currents that operate on the smaller scale. There are

three types of coastal currents - upwelling, longshore currents, and rip currents.

Upwelling is probably the most important of all coastal currents. Upwelling is defined as the rising

of colder, deep water to the ocean surface. If you recall from previous lessons, isn’t colder water

denser, so why does it rise to the surface? This phenomenon happens because near coastlines,

winds are typically very strong. These strong winds blow on the ocean surface and actually push

the surface water away from the shore. Because the surface water has been displaced, there is

now a “gap” on the ocean surface. Thus, the deeper, colder water rises to fill the “gap”.

Upwelling is especially important since plankton and nutrients are more commonly found in

deeper, colder waters. This means that upwelling supports fish populations that survive on

plankton and, thus, human fishermen.

Longshore currents are powerful currents that run parallel to the shore. Because these currents

are so close to the shoreline, they transport large amounts of sand and other sediments and

deposit the load elsewhere. This transport is called longshore drift. Longshore drift is especially

bad for beachside buildings because over time, the ground under the building can actually be

eroded away too, causing the house to collapse. Where this sand is deposited, different features

form. A spit is a stretch of sand connected to the mainland that extends into the ocean. A barrier

or barrier island is a sand dune not connected to the mainland.

Rip currents are the most dangerous coastal current. Rip currents happen on beaches. If you’ve

ever gone to beach, when you watch the waves, do you ever see the water recede once it

contacts the sand. The water doesn’t remain on the beach forever - it flows backwards towards

the ocean again. On some beaches, this backwards flowing is extremely powerful, and that is

when a rip current forms. Many swimmers have died from being trapped in rip currents, so next

time, pay attention to any warnings. If you ever see foam or debris floating away from the beach

rapidly, it’s probably a rip current.





Worksheets

Teacher’s Note: The purpose of this worksheet is to teach students the different types of

tides and how tidal patterns are factored into decisions that actually affect us.

Worksheet:

https://drive.google.com/file/d/0B8yQoHxsmWNxVnh2WTI2ODNDSmc/view?usp=sharing



https://drive.google.com/file/d/0B8yQoHxsmWNxVnh2WTI2ODNDSmc/view?usp=sharing



Lesson 4 Marine Life

Summary

1. Subject(s): Ocean layers and different ocean ecosystems



4. Objective: Students will learn about the different ocean layers and the ecosystems

associated with them.

Key Skills: Students should be able to explain the different layers of the ocean and

the various ocean ecosystems.

5. Time Allotment:

Powerpoint

https://docs.google.com/presentation/d/1sGRK60X-dmE9AWaoWOL162Gu_LZ3RIxAqpqQlnrgHR

Q/edit?usp=sharing

Lecture Transcript

Marine Life Overview

The oceans are a habitat teeming with life. Filled with millions of animals, plants, and other

organisms, marine ecosystems account for 50 to 80 percent of all life on Earth. Even though 1.5

million species have already been discovered, much of the ocean is still uncharted territory:



https://docs.google.com/presentation/d/1sGRK60X-dmE9AWaoWOL162Gu_LZ3RIxAqpqQlnrgHRQ/edit?usp=sharing

https://docs.google.com/presentation/d/1sGRK60X-dmE9AWaoWOL162Gu_LZ3RIxAqpqQlnrgHRQ/edit?usp=sharing



scientists estimate there are still 2 to 50 million life forms left to find. From the shallowest tide

pools to the deepest trenches, you will always find something living.

This marine life is fragile, however. As you will see later on, these organisms are valuable to us,

but human activities such as overfishing and littering have put them under attack. It’s our

responsibility to make sure oceans remain beautiful and lively.

Ocean Life Building Blocks

Plankton form the building blocks of ocean habitats. Plankton are tiny, tiny organisms we can’t

see that float with ocean currents. They are important because they are a major food source for

ocean animals - everything from small shrimps and anemones to the largest whales feed on

plankton. From an ecological standpoint, plankton for the bottom of the food chain.

There are 2 types of plankton. Zooplankton are animal planktons - to survive, they feed on

smaller planktons. Phytoplankton are plant planktons - to survive, they convert energy from the

sunlight to their own food source.

Surprisingly, plankton enjoy cold water. You will find more plankton in the near freezing waters of

the Arctic than the tropical beaches of Hawaii. Plankton enjoy cold waters because they usually

have more nutrients. The abundance of plankton near the Arctic and Antarctic is what allows

marine life to thrive there.

Light and the Oceans

Not all regions of the ocean receive light. The deeper you go, the less sunlight reaches that

region of the ocean.

The upper 200 meters, about 650 feet, of ocean is called the euphotic zone, or - more easy to

remember - the sunlight zone. This zone has sunlight, so it is warmer and supports phytoplankton

(remember? phytoplankton need sunlight to produce their own food).

The middle zone, called the twilight or disphotic zone, receives very little sunlight and extends

from 660 feet to nearly 3000 feet. Here animals are adapted to darkness and high pressure. Fish





have larger eyes, and some smaller organisms can glow in the dark. Some animals here include

zooplankton, octopi, krill, lobsters and crabs, eels, grey whales, sperm whales, squids, and some

large fish species.

The deepest zone, called the midnight or aphotic zone, is all regions of the ocean deeper than

3300 feet. The environment here is basically pitch black. Animals in this zone are the most

unique. First, at this zone, scientists refer to a phenomenon called a “rain of death” - essentially,

all organisms that die in the sunlight and twilight zones fall to the midnight zone. These carcasses

and dead plankton serve as the primary food sources for many organisms.

Another interesting thing to take note of is underwater volcanoes. Near mid-ocean ridges, there

are special underwater volcanoes called hydrothermal vents that eject different chemicals and

minerals from the Earth. Despite the extreme conditions, some organisms such as tube worms

and crabs actually survive here, relying on the chemicals ejected by the volcanoes to produce

food. Yes, even at the deepest depths and hottest temperatures, you will still discover life.

Habitat Focus: Coral Reefs

There are so many habitats in the ocean, but one key ecosystem everyone must understand is

coral reefs. Coral reefs can be found in tropical waters, and they are a home to 25% of all marine

species. Humans rely on reefs for fishing and tourism, and in places where storms are common,

coral reefs act as crucial wave breakers.

Contrary to common belief, corals are not plants. Corals are made out of individual units called

polyps. Polyps are small and look like upside-down jellyfish. Like jellyfish, polyps also have

stinging tentacles they use to catch floating plankton, and some glow in the dark. What gives

corals their beautiful colors is the algae. Algae called zooxanthellae actually live in the polyps;

these microscopic algae help produce extra food for the coral by converting sunlight to food,

while the polyp provides a home. This cooperation is called symbiotic mutualism, a relationship

where both the coral polyp and algae benefit. (The following slide of pictures depicts polyps and

a diagram of a polyp and algae. In the rightmost image, the orange-brown dots are actually

zooxanthellae living in the polyp)





Reefs are huge structures. The Great Barrier Reef by Australia is the largest living structure in the

world at 1400 miles long. Reefs take millions of years to grow because coral grow so slow. Hard

corals form the backbone of the reef. Hard corals are special because their polyps secrete

calcium carbonate, a very hard mineral. Over time, the calcium carbonate accumulates, giving

more space for polyps to grow.

Because coral reefs grow so slowly, they are considered very fragile ecosystems. Any changes in

the environment can kill the coral. When the water becomes too warm or too cold, the

zooxanthellae actually escape the polyp; this causes the polyp to lose color in an event called

bleaching and eventually starve to death. If there is pollution in the water, this not only poisons

the polyp, but it can block sunlight and prevent the algae from making food. Finally, powerful

storms can completely destroy reefs if waves are powerful enough. The greatest threat to coral

reefs today is humans. Our littering, pollution, fishing practices, and contributions to climate

change harm reefs. For instance, in some countries, fishermen use dynamite to blow up entire

reefs to catch dead fish. Right here in the US, irresponsible boaters drag their boats through

reefs, destroying hard corals If we do not change our ways, more than 90% of our coral reefs will

die by 2050.

Activity

Ecosystem Modeling

Teaching Note: The purpose of this activity is to ensure students conceptually and visually

understand the diversity of marine ecosystems.

Materials: plain clay, cardboard, construction paper, toothpicks, paint, Internet access,

glue, tape

1. Distribute clay, construction paper, toothpicks, glue, tape, cardboard, and paint to

each group. Assign each group one of the following marine ecosystems: kelp

forests, tide pools, coral reefs, seagrass beds, hydrothermal vents, and deep sea

reefs.





2. With the materials and online research, students should recreate a model of the

ecosystem they have been assigned.

3. After the models have set, have each group present the following information

about their specific ecosystem: location, 4 unique organisms, importance to

humans, how it relates to another group’s ecosystem, and 1 fun fact.





Lesson 5 Humans & The Oceans

Summary

1. Subject(s): Human activities and their impacts on the oceans.



4. Objective: Students will learn about the different ocean layers and the ecosystems

associated with them.

Key Skills: Students should be able to explain the different layers of the ocean and

the various ocean ecosystems.

5. Time Allotment:

Powerpoint

https://docs.google.com/presentation/d/1hC5x3GuzOfO9N11Cju04-m9wUK8lNVD4BmP_24Bb_Y

M/edit?usp=sharing

Lecture Transcript

Global Warming & Climate Change (Slide 2,3)

By now, most of us know global warming and climate change are two immense problems we

have to face. But before we can think of solutions, we must first understand how global warming

and climate change works in the first place.



https://docs.google.com/presentation/d/1hC5x3GuzOfO9N11Cju04-m9wUK8lNVD4BmP_24Bb_YM/edit?usp=sharing

https://docs.google.com/presentation/d/1hC5x3GuzOfO9N11Cju04-m9wUK8lNVD4BmP_24Bb_YM/edit?usp=sharing



99% of scientists agree that humans are responsible for the impending climate disaster. But what

is it that we do that has such large impacts? There are three main fossil fuels that humans depend

on - coal, natural gas, and oil. Almost every part of our lives involves burning these fuels. When

we drive, our cars burn gasoline, which comes from oil. When we turn on the lights, the nearest

power plant is probably burning coal to generate power. When we cook or heat our homes, our

stoves and heaters burn natural gas. All this burning has severe consequences as greenhouse

gases are released into the air. Greenhouse gases include carbon dioxide (CO2), methane, and

sulfur dioxide. These greenhouse gases are invisible, and when they reach our atmosphere, they

form a blanket around the Earth that traps in heat from the Sun. Usually, the heat the Earth

receives from the Sun is reflected back into space, but with this layer of greenhouse gases in our

atmosphere, heat is reflected back onto the Earth’s surface and is trapped for a long time. This

trapped heat is what’s responsible for the phenomenon we call global warming.

Global Temperature Trend (Slide 4)

Global warming has been observed since the early 1900s. The 1800s and 1900s were when

humans first started burning massive amounts of fossil fuels. If you look at the graph from NASA,

you can see that global average temperatures have been on a rise since then.

Direct Ecological Impacts (Slide 5)

This increase in temperatures has direct impacts on the ocean’s ecosystems. First, because

water temperatures are dramatically warming with the atmosphere’s temperatures, many fish

species can no longer bear living in their original environments. This has caused them to move

northward or southward towards the poles in search of cooler environments. In their new

environments, these fish disrupt the balance of Arctic and Antarctic marine ecosystems by

outcompeting the species that originally lived there. If you look at the diagram at the left, you can

clearly see how Arctic fishes’ habitats, the regions outlined in purple, have shrunk over the past

thirty years while the habitats of temperate fish, the regions outlined in orange and red, have

expanded. Fish migrations have also threatened fishermen. These days, fishermen have to travel

farther and farther just to get a catch.





Another direct ecological impact is the death of coral. From the previous lesson on marine

ecosystems, we know that coral reefs are extremely fragile ecosystems, and that even small

ocean temperature increases can kill coral. That’s exactly what’s happening right now in many

parts of the world - coral and the species that depend on them are dying due to rising

temperatures. Even the Great Barrier Reef, the largest coral reef in the world, has suffered greatly

from unusually warm waters.

Sea Level Rise (Slide 6)

One serious long term impact of global warming is sea level rise. Most of us already know that

sea level rise is partially caused by the melting of land ice. As glaciers and ice caps in the Arctic,

Antarctic, and Greenland continue to fragment and melt, this meltwater is entering the ocean and

causing sea levels to increase. Greenland’s melting ice is one of the greatest concerns for

scientists. If all of Greenland’s ice melted, sea levels would increase by 22 feet - that’s the height

of a two story building. Right now, Greenland’s melting contributes to a 1 millimeter increase in

sea levels every year, but if temperatures continue to warm, this rate will only increase. The

second cause behind sea level rise is thermal expansion. When water is warmer, it actually takes

up more volume. That means, that as the oceans have been getting warmer and warmer, they

have also been getting larger and larger.

There are several impacts to sea level rise. Right now, NASA reports that by 2100, sea levels may

rise by 11 to 78 inches, depending on whether or not we change our greenhouse gas emissions.

Higher sea levels means bigger storm surges during hurricanes and typhoons that can wipe out

entire towns and cities. In fact, up to 650 million people globally are at risk for increased flooding

due to sea level rise. If all these people are forced to move due to natural disasters and become

climate refugees, that would be a huge humanitarian crisis.

Ocean Acidification - Diagram (Slide 7)

Often overlooked, ocean acidification is another serious threat to our ocean’s health. Not directly

caused by higher temperatures, ocean acidification is actually a result of greater CO2 levels in

the air. Before we jump into why this is serious, let’s get a brief overview of how our oceans are

growing more and more acidic. When the oceans absorb CO2 from the air, the carbon dioxide

reacts with water molecules and carbonate ions to form bicarbonate ions. This process is





detrimental since it decreases the pH of the oceans - the lower the pH, the more acidic the

oceans are.

Ocean Acidification - Impacts (Slide 8)

Let’s take some time to imagine why ocean acidification is problematic. Imagine putting a tooth in

soda - soda is acidic by the way. If you wait several weeks, you’ll see the tooth will be completely

dissolved. The bottom line is acidic solutions with lower pH values break down things like bones

and skeleton, especially if they contain calcium (an element that is used to build calciums and we

obtain it from milk). As we’ve touched upon before when we discussed sediments and coral

reefs, hundreds of marine organisms rely on calcium carbonate, a compound containing calcium,

to build their shells and internal skeletons. Because oceans are becoming more and more acidic,

these organisms’ shells and skeletons are literally slowly dissolving. If you take a look at the

image on the left, you can see the effects of ocean acidification very clearly. In the 2005

snapshot, the coral are thriving. In the 2010 snapshot, the corals don’t even exist anymore;

there’s barely a trace of them since their skeletons have all dissolved away.

Activity

Solutions Debate

Teaching Note: The purpose of this activity is for students to better understand how

human needs and activities often conflict with the health of our oceans. Through debates,

students should have a sharper grasp of how important oceans are to our survival.

1. Give each group a sheet of paper, and ten minutes per debate to discuss/research

solutions and arguments. Refer to the following prompts for guidance, and assign

sides to make the debate even more challenging!

a. In many poorer coastal communities, fishermen depend on fishing from

coral reefs to survive. However, these fishing practices are often

destructive - some fishermen overfish while others use dynamite to kill

hundreds of organisms at the same time. Should governments respond to

this issue? How should governments approach this issue?





b. Today, much of our understanding of ocean currents comes from an

accident that happened many years ago. After a shipment of rubber ducks

fell into the ocean, scientists were able to track the floating plastic ducks to

see where the surface currents took them. Should more of these

investigations be carried out, even if they involve polluting the oceans?

c. Tidal energy and offshore wind farms are two rapidly developing

renewable energy sources. One downside to these sources is that they

often damage local ecosystems. Assign one group to defend the

construction of these structures and assign the other group to defend the

prohibition of these structures.

d. The Earth currently has a freshwater crisis - many countries are running out

of water. Some coastal nations have turned to constructing desalination

plants. Desalination plants are essentially buildings that convert seawater

to freshwater by filtering the salt and dumping it back into the ocean. This

salt destroys surrounding organisms and affects ocean circulation patterns.

What should be done about this conflict?

2. While each pair of groups debates, remind students to take notes. At the end of

each debate, ask the class for their input on the situation.





v v

For more information about Stemnova, please check out our website: stemnova.education. At Stemnova, we believe it takes a community to create change, and we hope you join our community of dedicated students, educators, and leaders hoping to spread love and opportunity for STEM to students everywhere.

OCEANOGRAPHY - Stemnova...Lecture Transcript (Core Curriculum) Plate Tectonics We tend to think of...

Documents

Transcript of OCEANOGRAPHY - Stemnova...Lecture Transcript (Core Curriculum) Plate Tectonics We tend to think of...