an Entity references as follows:
The hydrosphere (from Ancient Greek ὕδωρ (húdōr) 'water', and σφαῖρα (sphaîra) 'sphere') is the combined mass of water found on, under, and above the surface of a planet, minor planet, or natural satellite. Although Earth's hydrosphere has been around for about 4 billion years, it continues to change in shape. This is caused by seafloor spreading and continental drift, which rearranges the land and ocean.