Rising Waters

Lesson at a glance: Students will reflect and explore how changes in arctic ice are causing changes in sea level.

Goal: Students will understand how much of the polar sea and glacial ice is receding over time and how these changes are affecting sea level.

Guiding Questions:

How is polar ice changing over time?
Is sea ice melting causing sea level rise?
Are glaciers melting causing sea level rise?
Is the rising temperature of the ocean causing sea level rise?

Oregon Content Standards:

Science

7.2E.1 Describe and evaluate the environmental and societal effects of obtaining, using and managing waste of renewable and non-renewable resources.

7.2E.3 Evaluate natural processes and human activities that affect global environmental change and suggest and evaluate possible solutions to the problems.

7.3S.1 Based on observations and science principles, propose questions or hypotheses that can be examined through scientific investigation. Design and conduct a scientific investigation that uses appropriate tools and techniques to collect relevant data.

7.3S.3 Evaluate the validity of scientific explanations and conclusions based on the amount and quality of the evidence cited.

8.2E.4 Analyze evidence for geologic, climatic, environmental and life form changes over time.

Ocean Literacy Principles

3. The ocean is a major influence on weather and climate.

3. f. The ocean has had, and will continue to have, a significant influence on weather and climate change by absorbing, storing, and moving heat, carbon and water.

Materials:

Science Notebooks
Water
Plastic Cups
Ice Cubes
Conical flask
Corks
Glass tubes
Thermometer
Clamp-on lamp
Floodlight
Dye or food coloring
Graph paper

Estimated Time: 3-4 Class periods

Activity:

Engage (15 minutes):

In the center of each lab table place a cup of ice. Ask students what geographical place is most defined by this item. They will likely say mountains, Alaska, etc. Have them reference a globe or map of the world and have them point out where on the map is most associated with ice. Help guide them to referencing the poles also known as the Arctic and Antarctic.

Provide affirmation to their suggestions and ask what kinds of ice they could find in polar zones. Insure that students can distinguish that there are different forms of ice in the arctic; Sea ice and glaciers. Sea ice is frozen ocean water. Glacial ice is on the land and accumulates from precipitation. Have students make this distinction in their science notebook and make notes on other differences between this ice they would expect (i.e. salt vs. freshwater, etc.).

Watch the video at http://oceantoday.noaa.gov/happennowarcticseaice/welcome.html.

“What do we know about sea ice and how it is changing?” It’s melting.

“Why should we care?” Create a list of ideas students have about the impacts of melting ice on a piece of chart paper that can stay displayed in the classroom. They will likely include sea level rise, animals dying, increase in climate change, etc.

Explain that we will first focus on learning if melting sea ice will cause sea level change.

Melting Sea Ice and Sea Level (30 minutes)

Guiding Question:

Is sea ice melting causing sea level rise?

Engage: (5 minutes)

Pose the guiding question to the class. Have them complete a Commit and Toss. On a piece of paper, have them respond to the question and explain why. Have them crumple up the piece of paper and when you say go, begin tossing the balls of paper around the room. Say stop and make sure each student has a response. Have students read the other students responses. For rowdier groups, do a commit and pass.

Sort the responses into two columns with those that think it will and those that won’t to see where most students’ current thinking is.

Explore (20 minutes):

As a demonstration or small groups use the following materials:

Water- the ocean
Ice cube- sea ice
1 clear plastic 6-8 oz. cup
Permanent felt tip marker or tape

Instructions:

Explaining to the students what each part of the demonstration represents begin to assemble the demo.
Pour water into the cup, so that the cup is about half full.
Add an ice cube to the cup and carefully mark the level of the water with a permanent marker or piece of tape.
Ask students to predict what will happen to the water level in their cup as the ice cube (iceberg) melts, and to record this prediction in their science notebook.
Let ice melt in the cup. Report changes in sea level in their cups.

Explain (5 minutes):

Ask the students if their predictions were correct. Ask for explanations for why the water level in the cup did not change. They can use analogies such as ice melting in a glass doesn’t cause it to overflow, etc.

Ask students to reflect on the following question in their science notebook: “If sea ice is not adding water to the ocean to cause sea level rise, what is causing sea level rise?”

Melting Glacial Ice and Sea Level (50 minutes)

Guiding Question:

Are glaciers melting causing sea level rise?

Engage (10 minutes):

Review with students that we know that sea ice is melting. Ask students to remember what happened to the water level of the cup when the ice cube melted. Review with them that the activity was to simulate the melting of sea ice in the ocean. Ask, “Did we find that sea ice was adding water to the ocean to cause sea level rise?”

Show them images of melting glaciers. What observations do they have about how sea ice and glacial ice are similar? They both appear to be melting over time.

“Since sea ice is not adding water to the ocean to cause sea level rise, could it be glacial ice?”

Let’s find out.

Elaborate (30-40 minutes):

Present students with some materials:

Plastic cup or other container that will hold water
Clay, rocks, or other material that does not float (land)
Ice cube (glacial ice)
Permanent marker or tape
Water (ocean)

Ask students how they might design an activity that simulates glacier or ice sheet melting. (A couple ideas are to mold a piece of clay into a mountain shape in the cup, mold clay around the mouth of the cup and place the glacier on that or to place a piece of wood in the cup to represent land.) Have them draw their design in their science notebook. Discuss student ideas to make sure their ideas will work. Then pass out materials and let them carry out the investigation.

“Are glaciers causing sea level rise?” Have them write their conclusions on what their models suggest.

Explain (10 minutes):

Affirm students that in fact, glacial ice is contributing to sea level rise but there are other contributing factors as well.

While sea ice melting does not add water to the ocean, it does help the ocean stay a cold temperature. As sea ice melts, the temperature of the ocean is rising.

Temperature and Sea Level Rise (50 minutes)

Elaborate (30 minutes):

Ask students to write a prediction in their science notebooks about what happens to a volume of water when it is heated, compared to its volume at room temperature. Will it become larger, become smaller, or stay the same?
Completely fill a conical flask with very cold water (for increased visibility, add a couple drops of food coloring)
Place the cork in the stopper.
Slide the thermometer and glass tube into the holes in the cork. The water level should rise a short way into the tube. Record both the temperature of the water and the water level in the glass tube.
Place the flask over the lamp.
Have the students draw the x and y axes of a graph on graph paper. Have them label the x-axis “time” and mark divisions for two minute increments. Label the y-axis “height” which will be the measurements of the height of the water in the flask.
Turn on the lamp and have the students record the measurements on their graph every two minutes.
Discuss why the level of water in the flask changed. Ask students to reflect on the following questions in their science notebook:

What does this experiment suggest might occur if the oceans warm?
Where would you expect the increase in sea level to be the highest?
Would you expect this expansion from the application of heat (also called thermal expansion) to be enough to cause coastal flooding?

Evaluation (20 minutes):

Have the students revisit the questions from the activities:

How is polar ice changing over time?
Is sea ice melting causing sea level rise?
Are glaciers melting causing sea level rise?
Is the rising temperature of the ocean causing sea level rise?
Why should we care about changes in the polar zones?

Use a “stand up- hand up- pair-up” strategy to share student writing. Students will find a partner and then take turns reading and listening from their science notebooks.

Walk around and listen to students exchanging ideas, making sure main points have been addressed. Reiterate the main points once the sharing is completed.

Extension:

Have students investigate local solutions for dealing with rising sea levels. Including but limited to: land management planning, dikes, pumping, barrier island, home design, etc.