What's Causing Sea-Level Rise? Land Ice Vs. Sea Ice

In this activity, students will learn about sea ice and land ice. They will observe ice melting on a solid surface near a body of water and ice melting in a body of water. Prior to the activity, students will predict what each situation will do to the level of water and then compare their prediction to what they observe.

• This activity can be done in groups or as a whole-class demonstration. The materials list above is for one group or one whole-class demonstration.
• This activity takes time, as a given quantity of ice has to melt. If you have students all day, the activity can start at the beginning of the day and be revisited at regular intervals throughout the day. If students meet for only a class period, consider accelerating the ice melt by placing the experiment near a warm lamp or a source of mild warmth.
• Be aware that the ice in the water will melt faster than the ice on the “land.”
• Be sure the clay surface will allow the melted land ice to flow into the body of water. Avoid pressing your fingers into the clay and creating depressions that will block the flow of water.

Sea level is rising, in part, because melting glaciers on land are adding more water to Earth’s oceans. Glaciers – large sheets of ice and snow – exist on land all year long. They are found in the mountains of every continent except Australia. Greenland and Antarctica contain giant ice sheets that are also considered glaciers. As temperatures rise, glaciers melt faster than they accumulate new snow. As these ice sheets and glaciers melt, the water eventually runs into the ocean, causing sea level to rise.

Icebergs and frozen seawater also melt in warm temperatures but are not significant contributors to sea level rise. This is because they are already in the water. The volume of water they displace as ice is about the same as the volume of water they add to the ocean when they melt. As a result, sea level does not rise when sea ice melts. While density differences between salt water and freshwater result in a difference between the volume of salty sea water being displaced by sea ice and the freshwater that would result from the melting of that sea ice, it is minimal and beyond the scope of this lesson.

Another contributor to sea-level rise is the increase in volume that occurs when water is heated, called thermal expansion. Both thermal expansion and ice melt are the results of the rise in global average temperatures on land and sea known as climate change.

• In which container did the water level rise more?
• How does this compare to your prediction?
• Why do you think this occurred?
• In what way is this related to global sea-level rise?
• Does the melting of Earth’s glaciers contribute to sea-level rise? How about the melting of icebergs?

• Students should make a prediction and provide reasoning for their prediction. The accuracy of their prediction is not as important as the fact that they made one and can communicate their reasoning.
• Groups should build the land-ice and sea-ice containers according to the directions.
• Groups should take measurements and record data at regular intervals.
• Groups should compare their results to their predictions and provide a reasonable explanation for what they observed.
• Students should be able to connect the model to the global events of ice melting and associated sea-level rise.

• Use the data from the student data sheet to create a line graph using spreadsheet software.
• Complete the "Lessons in Sea-Level Rise" activity.

• Climate Change Lessons and Activities from JPL Education – These standards-aligned lessons feature NASA missions and science and explore the changes happening on Earth, from sea-level rise to global warming.
• NASA Climate Change website – Explore news, mission data, images and vital signs that track the changes happening on Earth.
• NASA Climate Change social media – Follow the latest news and updates from NASA Climate Change on: Facebook | Twitter | Instagram | YouTube
• NASA Sea Level Change Portal
• Images of Change – Compare satellite images taken at different periods to see how Earth is changing.
• Infographic: Sea-Level Rise
• Infographic: Earth's Carbon Cycle Is Off Balance
• Climate Kids website – Games, projects, and activities all about Earth and climate for children between the ages of 8 and 13.