Hydrosphere

What distinguishes the Earth from the other planets is the presence of the seas and oceans. Satellite pictures show the Earth as a “blue” planet, because two thirds of its surface are covered by huge masses of water. The whole of the earth’s environments where water is present in its liquid, solid or gaseous state is called hydrosphere. Most water can be found in the oceans, underground waters and in its solid state as ice in polar hemispheres. Water contained in the atmosphere as water vapour is instead just a very small part of the total amount. But this small part is very important in order to maintain the climate and feed the underground layers. Generally speaking, the hydrosphere can be divided into two different environments: salty water basins (seas and oceans) and fresh water basins. The main feature that distinguishes salty water basins from fresh water basins is their high salt content (or salinity), which is generally 35 grams per litre. Fresh water basins (or continental waters) can be divided into surface waters (rivers, lakes, lagoons, marshes) and underground waters (deep layers, surface layers and springs).

Special reports

  • 26 February 2014

    How much water is on your plate?

    Water footprint and water consumption...

    15 April 2014

    How rich are we …. in blue gold?

    Water footprint, water availability and use on a planetary scale...

    8 July 2022

    Who’s coming to dinner

    A shark in my hamburger Summer is finally here! As usual, we have waited for it all year long and…

  • 13 May 2018

    Small steps, great footprints

    Have you ever wondered how much space is taken up by an apple or a steak?...

    26 August 2022

    Which is coldest, the Arctic or Antarctica?

    As we face the hottest summer in years, let's try to answer this refreshing question: is it colder at the…

    7 October 2021

    Water grabbing

    “Clear, sweet fresh water,” wrote Petrarch, by many considered a precursor of Italian literature. Before him, St. Francis dedicated two…

  • 17 May 2021

    Lost ice

    According to a study conducted by a French and Swiss research team recently published in the leading journal Nature, continental…

    15 April 2021

    Oceans of plastic

    The invisible invasion of microplastics...

    26 December 2019

    Life in Antarctica

    How is it possible to live and work in Antarctica...

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Facts