3. The Earth System
“Earth is a complex
system of interacting
physical, chemical and
and provides a natural
experiments have been
running since the
beginning of time.”
4. Earth As A Closed System
Closed system: exchange of energy but negligible
exchange of mass with surroundings
6. Earth System Science
Earth is a dynamic body
with many separate, but
highly interacting parts or
Earth system science
studies Earth as a system
composed of numerous
parts, or subsystems.
9. The Earth is a system consisting of four major
Geosphere: comprises the solid Earth and includes
both Earth’s surface and the various layers of
the Earth's interior.
Atmosphere: gaseous envelope that surrounds the
Earth and constitutes the transition between its
and the vacuum of space
Hydrosphere: includes all water on Earth (including
surface water and groundwater)
Biosphere: the life zone of the Earth and includes all
living organisms, and all organic matter that has
not yet decomposed.
Earth’s Four Spheres
11. The Atmosphere
The Earth is surrounded by a blanket of
air, which we call the atmosphere.
• The atmosphere consists of four
unique layers (the troposphere, the
stratosphere, the mesosphere, and the
• The atmosphere reaches over 560
kilometers (348 miles) up from the
surface of the Earth.
• The atmosphere is primarily
composed of nitrogen (about 78%) and
oxygen (about 21%). Other
components exist in small quantities.
• consists of a mixture of gases composed primarily of
nitrogen, oxygen, carbon dioxide, and water vapour
•The troposphere (0-10
km) constitutes the
climate system that
maintains the conditions
suitable for life on the
exosphere are zones of
components in the far
reaches of the
(10 to 50 km),
contains ozone that
protects life on the
planet by filtering
radiation from the
13. Atmosphere: Interactions with other Earth System components
Hydrosphere: The gases of the atmosphere readily exchange
with those dissolved in water bodies (e.g. oceans, lakes, etc.)
Biosphere: The atmosphere supplies oxygen and carbon
dioxide that form the basis of life processes (photosynthesis
Geosphere: Gases in the atmosphere react with water to
produce weak acids that aid in the breakdown of rock.
15. System Interactions
Hurricanes (atmosphere) sweep
across the ocean (hydrosphere) and
onto the land (geosphere), damaging
the dwellings of people (biosphere)
who live along the coast.
16. The Biosphere
The biosphere is the “life zone” of the Earth, and includes all
living organisms (including humans), and all organic matter that has not
• The biosphere is structured into a hierarchy known as the food chain
(all life is dependant on the first tier – mainly the primary producers
that are capable of photosynthesis).
• Energy and mass is transferred from one level of the food chain to the
17. Biosphere: Interactions with other Earth System components
Atmosphere: Life processes involve a many chemical
reactions which either extract or emit gases to and from the
atmosphere (e.g. photosynthesis consumes carbon dioxide
and releases oxygen, whereas respiration does the
Hydrosphere: Evaporation of water from leaf surfaces
(transpiration) transfers water to the atmosphere.
Geosphere: The biosphere is connected to the geosphere
through soils (mixtures of air, mineral matter, organic matter,
and water). Plant activity (e.g. root growth and organic acid
production) are also for the mechanical and chemical
breakdown of the rocks.
The hydrosphere contains all the water
found on our planet.
• Water found on the surface of our planet
includes the ocean as well as water from lakes
and rivers, streams, and creeks.
• Water found under the surface of our planet
includes water trapped in the soil and
• Water found in our atmosphere includes
• Frozen water on our planet includes ice caps
• 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.
20. Atmosphere: Water is transferred between the hydrosphere
and biosphere by evaporation and precipitation. Energy is
also exchanged in this process.
Biosphere: Water is necessary for the transport of nutrients
and waste products in organisms.
Geosphere: Water is the primary agent for the chemical and
mechanical breakdown of rock (weathering), to form loose
rock fragments and soil, and sculpts the surface of the
Hydrosphere: Interactions with other Earth System components
The geosphere is the solid
Earth that includes the continental
and ocean crust as well the various
layers of Earth’s interior.
• 94% of the Earth is composed of
the elements oxygen, silicon, and
• The geopsphere is not static
(unchanging), but its surface
(crust) is in a constant state of
• Mineral resources are mined
from the geosphere.
23. Geosphere: Interactions with other Earth System components
Atmosphere: volcanism spews significant amounts of gases
into the atmosphere. For example, volcanoes inject large
amounts of sulphur dioxide to the upper atmosphere, resulting
in global cooling.
Hydrosphere: The formation of many minerals involve
incorporation or release of water. Also, water speeds up
chemical reactions that produce or destroy minerals, and aids
in the melting of rock.
Biosphere: Nutrients released from rocks during their
breakdown are dissolved in water (to be used by aquatic
24. System Interactions
Volcanoes (geosphere) erupt, sending
ash and gases into the air (atmosphere)
and sending lava and ash down onto
surrounding forests (biosphere) and
human habitations (biosphere).
Atmosphere Biosphere http://www.ecuador-
25. System Interactions
Earthquakes (geosphere) can damage
buildings which may kill people
(biosphere), as well as cause fires which
release gases into the air (atmosphere).
Earthquakes in the ocean may cause a
tsunami (hydrosphere) which can
eventually hit land and kill both animals
and people (biosphere).
26. Where Do Humans Fit In ?
As components of the biosphere, humans are temporary
receptacles of the matter and energy that flows through
the Earth System
“You are what you eat, drink, and breathe”
Human health is, to some degree, a function of how this
flow of matter and energy flows through, and interacts
with, the human body
In many cases, problems of human health are
fundamentally linked to the natural distribution of Earth
27. The Bottom Line
Considerations on how processes within the Earth System
interact are extremely important in the understanding of
the real world !
Understanding physical and chemical processes in the
Earth System is as important as understanding
biological entities in terms of understanding biological
systems (all are connected)
Let’s break down some walls this term !
Give two examples of how the Earth
system’s four parts can interact with each
Example: Animals (biosphere) can wear paths
in Earth’s surface (geosphere).
Identify the parts involved in the following
Wind blows a sailboat across a lake.
A bear digs under a log to search for good.