A1-3 The Hydrosphere

The hydrosphere is the subsystem that includes all the non-frozen water on the Earth. Water covers 71% of the Earth’s surface. The Earth’s oceans account for 97% of the Earth’s water. The remaining 3% is found as freshwater in bodies such as lakes, rivers, and groundwater.

Try This!

The distribution of the Earth’s water

These stacked bar charts illustrate the distribution of the Earth’s water.

The distribution of Earth's water.
  1. Where is the majority of freshwater stored?

    The majority of freshwater (68.7%) is stored in glaciers and ice caps.
  2. The amount of freshwater in the world is estimated to be approximately 35,027,000 cubic kilometers (8,403,424 cubic miles). Calculate the volume of water (in cubic kilometers) stored in ice caps and glaciers.

    68.7% × 35,027,000 km3 ≈ 24,100,000 km3
  3. Calculate the approximate volume (in cubic kilometers) of freshwater stored in lakes.

    87% × 0.3% × 35,027,000 km3 ≈ 91,000 km3