The Earth system consists of four main spheres - the geosphere, hydrosphere, atmosphere, and biosphere. The geosphere is the solid part of Earth, the hydrosphere is the liquid water, the atmosphere surrounds the planet, and the biosphere contains all living things. These spheres continuously interact as energy and matter cycle through the system. Changes to one sphere, like an increase in greenhouse gases, can impact the entire Earth system by altering Earth's energy budget and potentially leading to climate change.

1. THE EARTH
SYSTEM

2. What is the Earth system?
•A system is a group of related objects or parts
that work together to form a whole.
•The Earth system is all of the matter, energy,
and processes within Earth’s boundary.
•Earth is a complex system made of living and
nonliving things, and matter and energy
continuously cycle through the smaller systems.

3. The Earth System M. Ruzek, 1999

5. What is the geosphere?
•The geosphere is the mostly solid, rocky part
of Earth. It extends from the center of Earth to
the surface of Earth.
•The thin, outermost layer of the geosphere is
called the crust. It is made mostly of silicate
minerals.
•Oceanic crust is 5 to 10 km thick. Continental
crust is 35 to 70 km thick.

6. What is the geosphere?
•The mantle is the layer that lies below the crust.
It is about 2,900 km thick.
•The mantle is made of very slow-flowing, solid
rock, consisting of silicate minerals that are
denser than the silicates in the crust.
•Earth’s central part, called the core, has a radius
of about 3,500 km. It is made of iron and nickel
and is very dense.

11. What is the hydrosphere?
•The hydrosphere is the part of Earth that is
liquid water.
•Oceans, lakes, rivers, marshes, groundwater,
rain, and the water droplets in clouds are part of
the hydrosphere.
•Water on Earth is constantly moving. It even
moves into and out of living things.

12. What is the hydrosphere?
Surface Water: Includes the ocean as well as water from
lakes, rivers and creeks.
• Ground Water: Includes water trapped in the soil and
groundwater.
• Atmosphere: water vapor.
• Frozen water: Includes ice caps and glaciers. Also
called the cryosphere.
• Only about 3% of the water on Earth is “fresh” water,
and about 70% of the fresh water is frozen in the form
of glacial ice. (0.9% in liquid form)

13. Distribution of Water on Earth

15. What is the atmosphere?
•The atmosphere is a mixture of mostly invisible
gases that surround Earth.
•It extends outward about 500 to 600 km from
Earth’s surface, but most of the gases lie within
8 to 50 km of Earth’s surface.
•The atmosphere is about 78 percent nitrogen, 21
percent oxygen, and 1 percent many other
gases.

16. What is the atmosphere?
•Minor gases in the atmosphere include
argon, carbon dioxide, and water vapor.
•The atmosphere contains the air we breathe.
•It also traps some energy from the sun,
which helps keep Earth warm enough for
living things to survive and multiply.

20. What is the biosphere?
•The biosphere is made up of living things and
the areas of Earth where they are found.
•Organisms usually need oxygen or carbon dioxide
to carry out life processes.
•Liquid water, moderate temperatures, and a
stable source of energy are also important for
most living things.

23. How do Earth’s spheres interact?
•All of the spheres of Earth interact as
matter and energy change and cycle
through the system.
•A result of these interactions is that they
make life on Earth possible.

24. How do Earth’s spheres interact?
•Earth’s spheres interact as matter
moves between them. In some
processes, matter moves through
several spheres.
•Earth’s spheres also interact as energy
moves from one sphere to another, and
back and forth between spheres.

25. What is the source of Earth’s
energy?
•Almost all of Earth’s energy comes from the
sun.
•A tiny fraction of Earth’s energy comes from
ocean tides and geothermal sources such as
lava and magma.

26. What is the source of Earth’s energy?
•Energy is transferred between Earth’s spheres,
but it is not created or destroyed.
•Any addition of energy to one sphere must be
balanced by an equal subtraction of energy from
another sphere.
•The movement of energy through Earth’s system
forms an energy budget.

28. What is the source of Earth’s
energy?
•When Earth’s energy flow is balanced, global
temperatures stay relatively stable over long
periods of time.
•Sometimes, changes in the system cause
Earth’s energy budget to become
unbalanced.

29. What can disturb Earth’s energy
budget?
• An increase in greenhouse gases traps more energy in
the atmosphere and decreases the amount of energy
radiated out to space.
• Polar ice and glaciers reflect sunlight. When the ice
melts, the exposed water and land absorb and then
radiate more energy than the ice did.
• In each case, Earth’s atmosphere becomes warmer,
which may lead to climate changes.

30. 1. Name the four main earth systems.
2. Which branch of science studies the
interactions between these earth systems?
3. A forest fire would effect which earth systems?
Atmosphere, Biosphere, Hydrosphere and
Geosphere
Earth System Science: Example is a scientist that
studies global warming.
All four: Fires (Biosphere) will destroy plant and animal
life while releasing smoke and other contaminants into
the atmosphere, hydrosphere and geosphere.