The Earth as a System

http://www.gly.bris.ac.uk/www/ess/

The Earth As a System

• A System is a collection of interdependent parts enclosed within a defined boundary.

• The earth is made up of different systems or subsystems called spheres.

http://www.icess.ucsb.edu/

Earth Science is the study of Earth’s systems

• Everything in Earth's system can be placed into one of four major subsystems or spheres.

Earth’s Spheres

The four spheres.• Lithosphere (land)

– contains all of the cold, hard solid land of the planet's crust (surface), the semi-solid land underneath the crust, and near the center of the planet.

• Hydrosphere (water)– contains all the solid, liquid, and gaseous water of the

planet, both on, above and below..• Biosphere (living things)

– all of the microorganisms, plants, and animals of Earth. • Atmosphere (air)

All Systems are Interdependent

• The spheres are closely connected, interfacing, overlapping and interconnected.

• Example– many birds (biosphere) fly through the air (atmosphere)– water (hydrosphere) often flows through the soil

(lithosphere).– Rocks (lithosphere) eroded by rain, wind

(hydrosphere/atmosphere). The rocks are broken down to minerals which are then used by plants and animals (biosphere).

Earth Processes are driven by internal or external processes

• Internal processes are driven by heat and radioactivity from the Earth’s core.

• External processes are driven by the energy of the sun.

External processes

• Eolian (wind) deposition, glaciations, stream erosion, chemical and physical weathering, hydrologic cycle.

Internal processes

• Heat flow, Tectonics (subduction, magma creation and movement), volcanism.

Matter

• Matter is anything which takes up space and has mass.– Solids– Liquids– Gases

Earth Power

• http://www.youtube.com/watch?v=-x8-KMR0nx8

Earth Systems

• Earth is a closed system.– A closed system is one in which no new matter can

enter and no matter can leave. • The only exception to this is when meteorites

hit the surface of the planet.• The amounts of carbon, water, oxygen, hydrogen,

and nitrogen on Earth are the same now as they were when dinosaurs were alive.

http://www.chatt.hdsb.ca/~flindallc/Text%20Files/Science%20&%20Technology%20Perspectives%207/Chapter%205/5.5.pdf

How do the amounts of matter on Earth remain the same over long periods of time?

–The answer is through recycling. • Matter is taken up from the

environment, used in life processes, and eventually returned to the environment where it can be used again. –Ecologists call this repeating pattern a

cycle.

Earth Materials

• What are Earth materials?• Minerals• Rocks• liquids• Gases– The Rock Cycle

Did the landforms on Earth always look like they do today?

Did the landforms on Earth always look like they do today?

• No, they have gone through many repeated episodes of formation, metamorphosis, destruction, reformation, metamorphosis, destruction, reformation, metamorphosis, destruction, reformation, metamorphosis, destruction, reformation, metamorphosis, destruction, reformation, metamorphosis, destruction, reformation, metamorphosis, destruction, reformation, metamorphosis, destruction, reformation, metamorphosis, destruction…

Plate Tectonics

• http://www.youtube.com/watch?v=GYVS_Yh6dTk

Where did the earth Come from?

• http://www.youtube.com/watch?v=QDqskltCixA&feature=fvsr

http://gsc.nrcan.gc.ca/urbgeo/natcap/images/fig-3_750.jpg

The Core

Driver of All Internal Processes

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AND NOW …

Correction: Oceanic crust is denser than Continental crust!!!!!!!!!!!!!!! • http

://www.youtube.com/watch?v=XC5v5ZXTul4

Earth’s Interior Structure

• http://www.youtube.com/watch?v=3xLiOFjemWQ&feature=fvw

• Structure of the Earth

Interior Forces

• As mantle material is heated its volume increases, and density decreases.

Repeat after me, volume up density down

Convection currents

Plate Boundaries

Carbon

All About Carbon

• http://www.npr.org/2007/05/01/9943298/episode-1-its-all-about-carbon

Why is Carbon Important?

• Virtually all multicellular life on earth depends on the production of sugars from sunlight and carbon dioxide (photosynthesis) and the metallic breakdown (respiration) of those sugars to produce the energy needed for movement, growth and reproduction.

Photosynthesis

• Plants take in CO2 from the atmosphere during photosynthesis, and release CO2 back into the atmosphere during respiration through the following reactions.

• Energy (sunlight) + 6 CO2 + H2O C6H12O6 + 6O2

• Respiration– C6H12O6 (organic matter) + 6O2 6CO2 + 6 H2O + energy

• The concentration of carbon in living matter (18%) is almost 100 times greater than its concentration in the earth (0.19%).

• So living things extract carbon from their nonliving environment.

• For life to continue, this carbon must be recycled.

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/CarbonCycle.html

Carbon Cycle

Carbon Cycle

Carbon Cycle

Photosynthesis vs. Rock Cycle

The amount of carbon taken up by photosynthesis and released back to the

atmosphere by respiration each year is about 1,000 X greater than the amount that moves

through the geological cycle on an annual basis.

• Why?

• Many attribute the 0.6 C increase in global average temperatures to increased CO2 levels in the atmosphere.

• If this is true then we can expect temperatures to continue to increase due to fossil fuel consumption and deforestation

• Annual Deforestation:

A total of almost 15.5 million hectares of forest world wide every year.

Deforestation has wide ranging effects

• The carbon cycle is impacted through not only the destruction of a carbon sink, but also through the burning of forests.

• The hydrological cycle is altered as the water table can no longer hold as much water, increased runoff, and habitat destruction results.

• Biodiversity falls as land is cleared.

Amazon Basin over 13 years