BIOGEOCHEMICAL CYCLES

Biogeochemical Big word; simple idea  Bio = life  Geo = earth  Chemical = substance So biogeochemical = substances involved with life on earth.

Water Cycle

Water Is Everywhere  75% of the earth’s surface is covered with water.  All living things contain water.  There is water in the atmosphere.

Water on the Move  Water continually cycles from the earth to the atmosphere and back again.

Evaporation  Water evaporates (changes from a liquid to a gas).

Condensation  Water condenses (changes from a gas to a liquid).

Precipitation  Water returns to earth’s surface in the form of rain, sleet, snow or hail.

The Very Simple Version Evaporation Condensation Precipitation

It’s more complicated than that.

Transpiration  Plants return water to the atmosphere. Plant sucks in water through roots Plant loses water through leaves

Perspiration  Animals return water to the atmosphere when they sweat, pant, breathe, etc.

Infiltration  Water goes into the ground. It filters through soil, rocks, etc. Diagram courtesy of the U.S. Geological Survey

Runoff  Some water moves along the surface of the ground collecting in low areas. Diagram courtesy of the U.S. Geological Survey

Ground Water  Water filters into soil and rock until it comes to rocks it cannot pass through.  Water may fill spaces in rocks and soil.  An aquifer is a pool of underground water.