Abstract

The hydrologic cycle describes the dynamic, water-circulation system of the Earth. Water we see today is the same water that was originally derived from degassing of volcanoes as the Earth cooled from the molten mass that was our primordial planet several billion years ago. This water has been continuously recycled by natural processes, changing from liquid to solid or vapor and then back again, moving and flowing endlessly in response to the physical and chemical conditions of the environment of our planet.