Earth's Frozen Water
Understand the cryosphere and its role in Earth's water system — the cryosphere is all frozen water on Earth (ice sheets, glaciers, sea ice, permafrost, snow cover); polar ice sheets hold about 69% of Earth's fresh water; if all polar ice melted, sea levels would rise over 65 metres; and the water cycle connects polar ice to the global system through evaporation, precipitation, and meltwater flowing into oceans
What a learner can do afterwards
- Define the cryosphere as all frozen water on Earth and name its components: ice sheets, glaciers, sea ice, permafrost, snow
- State that polar ice sheets hold approximately 69% of Earth's fresh water
- Explain how polar ice connects to the global water cycle and what would happen if it all melted (65m+ sea level rise)
The lesson
You already know about glaciers and ice sheets. Scientists have one big word for every kind of frozen water on Earth: the cryosphere. It includes ice sheets, glaciers, floating sea ice, frozen ground called permafrost, and snow cover.
Zara imagines pouring all of Earth's fresh water into 100 cups. About 69 of those cups would be locked away as ice at the poles. Only the rest would be rivers, lakes, and underground water she can actually use.
Even frozen, that water is still part of the water cycle you already know. Sunlight warms the ice, some of it melts and evaporates, clouds form, rain falls, and meltwater rivers carry the water back to the sea.
The cryosphere holds most of Earth's fresh water as ice, and it is still part of the water cycle: if it all melted, seas would rise over 65 metres.
Watch it
Where it sits
This opens up
Nothing builds on it yet.
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.