Earth’s Systems

BIOSPHERE The biosphere is made up of living organisms and the include the areas of Earth where life can be found. The biosphere contains a variety of factors that certain plants and animals need in order to survive. Energy enters the biosphere through sunlight. This form of energy starts in plants as photosynthesis. This energy is then passed onto the organisms that eat these plants. Energy can also be transferred to organisms that eat each other. -EX) A polar bear cannot live in the Sahara Desert!

HYDROSPHERE The hydrosphere is made up of water both in and on the Earth. This includes the water in the oceans, lakes, rivers, glaciers, and polar ice caps. Clouds and rain are also part of the hydrosphere. Approximately 71% of the earth’s water is in the oceans. There are FIVE major oceans: Pacific, Atlantic, Indian, Southern and Arctic. Energy is circulated through the oceans through convection currents. This is where the cooler, more dense water sinks to the bottom while the warmer less dense water rises towards the surface.

ATMOSPHERE The atmosphere is a mixture of invisible gases that surround the Earth. -It is made up of 78% Nitrogen (N); 21% Oxygen (O); 0.9% Argon (Ar); and 0.03% CO2 There are FOUR main layers to the Atmosphere: Troposphere; Stratosphere; Mesosphere and Thermosphere The atmosphere is heated through a process known as convection. -Convection is is the movement of heat through matter; in the atmosphere this matter is in the form of air. It is where the cold air sinks and the warm air rises.

Geosphere The geosphere makes up the solid rock of Earth. -It can be divided into 2 layers based on chemical and physical properties COMPOSITIONAL LAYERS: -CRUST: thin, outermost layer -MANTLE: hot layer of rock between the crust and core -CORE: in the center; made of iron (Fe) nickel (Ni) PHYSICAL LAYERS: LITHOSPHERE: cold, brittle, outermost layer ASTHENOSPHERE: solid, plastic like layer upon which the tectonic plates move MESOSPHERE: the lower, solid layer of the mantle OUTER CORE: made of liquid iron (Fe) and nickel (Ni) INNER CORE: made of solid iron (Fe) and nickel (Ni)