Cool Science Cool Science from Cold Places: from Cold Places:

Classroom Activities to Classroom Activities to Explore the Cryosphere Explore the Cryosphere and Polar Regionsand Polar Regions

Lisa GardinerSandra HendersonBecca Hatheway

UCAR Office of Education and Outreach, Boulder, CO, www.eo.ucar.edu

Cool ScienceWorkshop:• Information about Earth’s

Polar Regions, a Windows to the Universe

resource• Glaciers: Then and Now• Model a Moving Glacier• Graphing Sea Ice Extent• Looking into Surface Albedo

*Happy International Polar Year!

Glaciers: Then and Now

• Students compare photographs of glaciers to observe how Alaskan glaciers have changed over the last century.

About Glaciers…

How glaciers change:– Glacial advance:

Glaciers become larger when more snow falls than melts.

– Glacial retreat: Glaciers become smaller when more snow melts than falls.

Continental glaciers (ice sheets) cover large areas of land.Alpine glaciers (valley glaciers) fill high mountain valleys.

Glaciers MOVE!Glacial ice flows slowly downhill in two ways:

– Internal deformation: plastic movement within the ice (think: slow-flowing honey.)

– Basal slip: the entire glacier slides on its base (think: slipping on a banana peel.)

What factors affect how fast a glacier moves?

Model a Moving Glacier

This activity allows students to experiment and discover how three variables affect glacier flow:

- valley slope - ice temperature - basal conditions (ground surface)

food coloring (optional)

½ cup warm water1 cup white glue

2 tsp. of Borax¾ cup warm water

Mix #2Mix #1

Models of glaciers using “flubber”

Flubber is a polymer that has the properties of both a liquid and a solid. The molecules in the flubber are loosely arranged and can slide past each other.

Flubber glacier

Actual glacier

Valley slope:

•Shallow

•Medium

•Steep

Basal conditions:

•Rough – sandpaper

•Normal – plain PVC pipe

•Lubricated – Foil and oil

Test it!What factors affect how fast a glacier moves?

Flubber in action

Pick a variable.

Make a hypothesis.

(e.g. the steeper the slope, the faster the flow.)

Ice Over Water: Sea Ice

• Sea ice is frozen seawater. It can be several meters thick.

• During summer much (but not all) of the sea ice melts.

• During winter more sea ice forms again.

Graphing Sea Ice ExtentStudents graph sea ice extent (area) in the Arctic and Antarctic

over a three-year period to learn about seasonal variations

Graphing Sea Ice ExtentThen, students graph sea ice extent over a 25-year period

to learn about longer-term trends.

Earth as a system: It’s all connected!

“I don’t live anywhere near glaciers or sea ice. Why should I care if the ice melts?”

Melting sea ice means less energy is reflected causing more global warming.

Melting glaciers means more water in the oceans causing sea level rise.

Credit: NSIDC

Data from 23 tide gauge stations on tectonically stable continental margins (R.A. Rohde/Global Warming Art Project)

Looking into Surface Albedo

• This activity demonstrates how the color of materials that cover the Earth affects the amounts of solar energy absorbed.

• Albedo is the amount of energy reflected by a surface

• Dark colors – low albedo• Light colors – high albedo

Check the flubber glaciers.

Resources:• Windows to the Universe Newsletter for Educators

(Sign up today! Form in your packet!)

• Earth’s Polar Regions www.windows.ucar.edu/polar.html

• Climate and Global Change www.windows.ucar.edu/climate.html

UCAR Office of Education and Outreach, Boulder, CO, www.eo.ucar.edu