The hydrosphere (from Greek hydor for water) comprises all water on Earth. Water exists on Earth as surface water (e.g. oceans, lakes, rivers), in the form of groundwater under the surface of the Earth, and in the atmosphere. Moreover, the frozen water bodies of the mountain glaciers, polar ice caps and sea ice are part of the hydrosphere.
In total Earth’s hydrosphere contains more than 1450 million cubic kilometers of water. The majority of this water, about 94%, forms the oceans.
Water in many respects is one of the key components of the Earth system. Due to the current temperatures on Earth water exists as gas, as a liquid and in solid form. This is the reason why it can participate in numerous processes on Earth. Many of these processes are vital for the existence of life.
Select a theme to see a list of case studies:
- Coastal changes
- Water surface temperature – global, regional, seasonal change
- Ocean currents – global, regional
- Ocean waves
- Water salinity
- River systems
- Ice – Glaciers
- Ice – Arctic sea ice
- Ice – Ice shields (Antarctica, Greenland)