Ice & Glaciers

Learn why not all polar ice is the same.

About Ice & Glaciers

Polar ice includes frozen ocean water, glaciers on land, vast ice sheets, floating ice shelves, seasonal snow, permafrost, and drifting icebergs. Each type forms and behaves differently.

Visual learning: These pages use real satellite, wildlife, glacier, and polar landscape images from Wikimedia Commons. Final image URLs should be browser-tested.

Antarctica — AntarcticaAntarctica is Earth's coldest continent and is covered by a huge ice sheet.

Polar Bear — Polar BearPolar bears are Arctic marine mammals that depend heavily on sea ice.

Emperor Penguins — Emperor PenguinsEmperor penguins survive the extreme cold of Antarctica.

Iceberg — IcebergIcebergs are floating pieces of freshwater ice that broke from glaciers or ice shelves.

Glaciers

Glaciers are moving masses of land ice formed from compressed snow.

Ice Sheets

Ice sheets cover huge land areas.

Sea Ice

Sea ice is frozen seawater.

Ice Shelves

Ice shelves are floating extensions of land ice.

Icebergs

Icebergs break from glaciers or ice shelves and float away.

Ice Cores

Scientists drill cylinders of ancient ice.

Ice Moves

Glaciers and ice sheets flow like very slow rivers.

Sea Level

Melting land ice adds water to the ocean.

Glaciers

Gravity slowly pulls glacier ice downhill.

Ice Sheets

Today the only continental ice sheets are in Greenland and Antarctica.

Sea Ice

Because it already floats, melting sea ice has little direct effect on global sea level, though it strongly affects climate and ecosystems.

Ice Shelves

They can slow the flow of glaciers behind them.

Icebergs

Most of an iceberg's volume remains underwater.

Ice Cores

Air bubbles and chemical signals in ice cores preserve records of past atmosphere and climate.

Ice Moves

Their speed changes with slope, temperature, meltwater, and the shape of the bed below.

Sea Level

Changes in Greenland and Antarctica are important to long-term sea-level projections.