Earth is studied with respect to four spheres of the natural enviroment
1. Atmosphere
2. Lithosphere
3. Biosphere
4. Hydrosphere
Lets take a look at these four spheres of the earth in bit more detail to understand how they help make up the earth.
Hydrosphere (Water)
The hydrosphere includes all the gaseous, liquid, and solid water of the planet earth. The hydrosphere stretches all the way from the Earth’s surface downward numerous miles into the lithosphere and high above the crust into the atmosphere. Most of the water in the atmosphere is in gaseous form and as it rises higher into the atmosphere it condenses to form clouds which fall back on earth as precipitation.
All the water in the hydrosphere is always in motion just like the atmospheric gases. The natural earth features depicting the hydrosphere are the rivers, streams, lakes, seas, oceans and the water vapor. Glaciers, which are the slowly moving masses of ice, are also part of the hydrosphere. 97% of all earth’s water is salty. Oceans carry most of the salty water while the majority of lakes and rivers carry fresh water. The earth’s temperature is highly influenced by the hydrosphere.
Very low temperatures are associated with icebergs, glaciers or icecaps; low to moderate temperatures are associated with the common types of precipitation like snow, rain, drizzle, sleet or hails; and high temperatures are tied to dry and hot conditions and evaporation. The glaciers, icebergs, and icecaps are also categorically called the cryosphere.