Water circulation

Water that is normally present in porous rocks, such as sand or gravel, fills all the voids in a continuous manner. However, in karst rocks, the water forms courses of water which at times become large underground rivers that flow in enormous galleries whose diameter is many meters wide and are many kilometres long. The water of the underground streams flows in the same way as those on the surface, and similarly they are subjected to floods caused by rainfalls on the surface (in caves, floods arrive with a certain delay in time, due to slow seeping in the catchement zone). Water is able to entrench and erode rock by means of mechanical abrasion processes, to transport sediments of various granulometries, and to create alluvial deposits inside caves.

Special reports

From the Multimedia section

Facts

  • 13 May 2011

    A walk underground

    The longest caves in the world are in Kentucky, the caves of Mammoth...

    24 February 2011

    And in underground tunnels?

    There are groups of terrestrial animals that eat insects, worms and other invertebrates...

  • 13 May 2011

    The climate underground

    Going down deep in the Earth’s crust, the temperatures increase gradually...

    Amphibians in a cave

    Proteus is an amphibian of white-yellowish or light pink colour...

  • Can you breathe in a cave?

    One of the most common beliefs is that in caves the air is often stuffy...

    Ice in caves

    In high mountain or high latitude environments, many caves can contain ice deposits...

  • A walk underground

    The longest caves in the world are in Kentucky, the caves of Mammoth...

  • 24 February 2011

    And in underground tunnels?

    There are groups of terrestrial animals that eat insects, worms and other invertebrates...

  • 13 May 2011

    The climate underground

    Going down deep in the Earth’s crust, the temperatures increase gradually...