Hydrosphere
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 your Case Study:
| Coasts as dynamic boundaries | |
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Alexandria, Egypt Sea level rise and reduced sediments from the Nile river modify the coastline. |
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Mississippi Delta, U.S.A. A changing delta due to sea level rise and reduced sediments from the Mississippi river. |
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Mont Saint-Michel, France An ancient abbey on an island between ebb tide and flood, tourist destination and oyster cultivation. |
| Water surface temperaturess | |
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Gulf Stream – North Atlantic Ocean currents affect the climate over large distances. |
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El Nino – Equatorial Pacific Large-scale oscillations of the Pacific Ocean currents influence the weather in large parts of the world. |
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Europe – Sea surface temperature Seasonal changes of the sea surface temperature |
| Glaciers as water bodies | |
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Columbia Glacier, U.S.A. Higher temperatures and the rising sea level lead to a rapid decay of the Columbia Glacier. |
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Aletsch Glacier, Switzerland The largest glacier of the Alps is an example of the retreat of alpine glaciers. |
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Kilimanjaro Glacier, Tanzania There are not many glaciers in the tropical climate zone, and they are shrinking. |
| Floods and flood protection | |
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Plattsmouth, U.S.A. Heavy rainfall in the Missouri Basin has caused severe floodings in 2019. |
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Derna, Libya Unusually heavy rainfall caused a dam failure and a disastrous flooding in 2023. |
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Venice, Italy To cope with the threat of the rising sea level, the flood protection system MOSE has been installed. |
