Earth Systems (4 physical systems)

    Lecture 3

    Earth Systems  (4 physical systems)

    Atmosphere 

– derived from the Greek words for air (atmo), 

      – Layer of gases that surround Earth. Allows you to breathe and protects earth.

    The air of our planet is composed of  79% nitrogen, and just under 21% oxygen,

      – Troposphere, Stratosphere, Mesosphere, Ionosphere (or Thermosphere), Exosphere and the Magnetosphere

               Lithosphere

§  Surface of the planet that forms the continents and the ocean floor.

§  derived from the Greek word for stone (litho)

§  This crust is inorganic and is composed of minerals.

§  It covers the entire surface of the earth from the top of Mount Everest to the bottom of the Mariana Trench.

    Hydrosphere

–       derived from the Greek words for water (hydro)

–       All the water on Earth (ocean, ice, and water vapor in the atmosphere)

–       Ninety-seven percent of the earth's water is in the oceans.

–       The remaining three percent is fresh water; three-quarters of the fresh water is solid and exists in ice sheets

    Biosphere

–       derived from the Greek word for life (bio).

–       Part of Earth where life exists.

–       Plants, animals, and one-celled organisms are all part of the biosphere

–       Most of the planet's life is found from three meters below the ground to thirty meters above it and in the top 200 meters of the oceans and seas.

•         All four spheres can be and often are present in a single location.

•         a piece of soil will of course have mineral material from the lithosphere.

•         Additionally, there will be elements of the hydrosphere present as moisture within the soil,

•          the biosphere as insects and plants,

•         the atmosphere as pockets of air between soil pieces.