The Dynamic Earth

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Chapter 3

• The Dynamic Earth

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Section 1 The Geosphere

• The Earth as a System
• The Earth consists of four parts
• Geosphere rock, soil, and sediment
• Atmosphere mixture of gases that make up the
  air we breathe
• Hydosphere the water on or near Earth
• Biosphere the part of the Earth where life
  exists

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Section 1 The Geosphere

• Discovering Earths Interior
• The composition of the earth has 3 layers
• Crust Earths thin outer layer
• Mantle beneath the crust makes up 64 of the
  Earth
• Core Earths innermost layer composed of the
  densest elements

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Section 1 The Geosphere

• Plate Tectonics
• The rigid outermost layer of the Earth is divided
  into pieces called tectonic plates.
• The continents are located on tectonic plates and
  move around with them.
• Most volcanoes, mountains, and earthquakes are
  caused by the plates pulling apart or crashing
  into each other

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Alfred Wegener

• German meteorologist
• Developed theory of continental drift
• Used the correlation method to find the theory of
  continental drift
• Pangaea single landmass at the beginning of
  time

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Section 1 The Geosphere

• Earthquakes
• Earthquakes occur along fault lines breaks in
  the Earths crust.
• Earthquakes are measured on the Richter scale.
• The smallest earthquake that can be felt is a
  magnitude 2.0. The largest ever recorded was a
  9.5 magnitude earthquake.
• Earthquakes can occur almost anywhere.

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Earthquake Movement

• www.news.bbc.co.uk/1/hi/world/4126809.stm

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Section 1 The Geosphere

• Volcanoes
• Volcanoes are built from magma melted rock.
• Volcanoes are often located near tectonic plate
  boundaries.
• Volcanoes can occur under the sea as well as on
  land.

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Section 1 The Geosphere

• Volcanoes (cont.)
• Volcanoes can cause mudflows, burying crops,
  buildings and trees.
• Major volcanic eruptions can change Earths
  climate for several years.
• Ash and gases can spread across the planet and
  block out some of the sun.
• Less sunlight means lower temperatures.

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Section 1 The Geosphere

• Erosion
• Erosion is the removal and transport of Earths
  surface by wind and water.
• Water erosion
• Created the Grand Canyon
• Caused major problems during Hurricane Katrina
• Wind erosion
• Indiana Dunes State Park is a good example
• Was a real problem during the Dust Bowl of the
  1930s

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Section 2 The Atmosphere

• Atmosphere mixture of gases that surround the
  Earth these gases include
• Nitrogen 78
• Oxygen 21
• Carbon dioxide, water, methane 1

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Section 2 The Atmosphere

• Atmosphere is made up of four layers
• Troposphere
• Stratosphere contains the ozone layer
• Mesosphere
• Thermosphere

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Section 2 The Atmosphere

• Energy from the sun is transferred to the Earths
  atmosphere in 3 ways
• Radiation the transfer of energy across space
• Conduction the flow of heat from a hot object
  to a cold object when the two objects touch
• Convection the transfer of heat by air currents

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Climate and Climate Change

• Difference between climate and weather
• Climate the long-term weather conditions at a
  particular place over a period of time based on
  previous records
• Weather weather conditions on a particular day

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Climate and Climate Change

• Factors Determining Climate
• Latitude distance from the equator measured in
  degrees north or south of the equator
• Atmospheric circulation patterns due to
  convection currents
• Oceanic circulation patterns El Nino/La Nina
  also due to convection currents
• Topography the surface shape of the land

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The Ozone Shield

• The ozone shield is made up of the ozone layer
• Ozone layer the area in the stratosphere where
  ozone is concentrated
• Ozone layer shields Earth from harmful radiation
  (ultraviolet radiation UV)
• UV can cause skin cancer
• Ozone layer is made up of ozone
• Ozone molecule made up of 3 oxygen atoms

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The Ozone Shield

• The ozone layer contains natural holes called
  ozone holes
• Ozone hole thinning of the ozone that occurs
  over the poles during the spring
• Chemicals in pollution (from car exhaust, aerosol
  cans, factories, etc.) can chemically react with
  ozone and destroy it
• The more pollution we produce, the more ozone we
  destroy.

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The Ozone Shield

• The more ozone is destroyed, the thinner the
  ozone layer or the larger the ozone hole.
• This lets more UV light into the atmosphere
• Causes (p. 337, table 1)
• Skin cancer
• Genetic mutations in plants and animals

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The Greenhouse Effect

• Greenhouse effect the process by which gases in
  the atmosphere trap heat near Earth (p. 339, fig.
  14)
• This is a NATURAL process.
• Major greenhouse gases are
• Water vapor
• Carbon dioxide
• Methane
• CFCs

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The Greenhouse Effect

• Pollution adds more of these gases to the
  atmosphere.
• This causes the earths temperature to rise
  because more radiation is trapped near the
  earths surface.
• How will this global warming effect the earth?

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The Greenhouse Effect

• Effects of global warming
• Melting ice and rising sea levels
• Change in global weather patterns
• Human health problems
• Heat-related deaths
• Respiratory illnesses
• Insect-borne diseases
• Severe impact on food supplies (agriculture)

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The Kyoto Protocol

• Requires countries to decrease emissions of
  carbon dioxide and other greenhouse gases a
  certain percentage each year until 2012
• In March of 2001, the United States decided not
  to sign the treaty.
• Most of Europe and other developed countries have
  signed it.

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Section 3 The Hydrosphere and Biosphere

• The Hydrosphere and Water Cycle
• Hydrosphere all the water on or near the
  Earths surface
• Water cycle continuous movement of water into
  the air, onto land, and then back to water
  sources

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Section 3 The Hydrosphere and Biosphere

• Steps of the water cycle
• Evaporation liquid water is heated by the sun
  and then rises into the atmosphere (steam or
  humidity)
• Condensation water vapor forms water droplets
  on dust particles and form clouds or fog
• Precipitation large droplets fall from clouds
  in the form of rain, snow, sleet, or hail

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Section 3 The Hydrosphere and Biosphere

• Earths Oceans
• The Earths oceans cover over 70 of the Earths
  surface
• Ocean water contains much more salt than fresh
  water
• Salinity the amount and concentration of salt
  in ocean water
• Temperature zones
• There are 3 different temperature zones in the
  ocean

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Section 3 The Hydrosphere and Biosphere

• A Global Temperature Regulator
• One of the most important functions of the ocean
  is to absorb and store energy from the sun
• This function is what regulates the temperature
  of the Earth

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Section 3 The Hydrosphere and Biosphere

• Ocean Currents
• The ocean has movements of water similar to
  streams called currents. There are 2 different
  types of ocean currents.
• Surface currents occur near the surface of the
  ocean they are driven by the wind
• Deep currents occur near the floor of the
  ocean they are very slow moving and COLD

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Section 3 The Hydrosphere and Biosphere

• Fresh Water contains very little salt
• Icecaps and glaciers
• Rivers, lakes and wetlands
• Groundwater
• Aquifers

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Section 3 The Hydrosphere and Biosphere

• The Biosphere the narrow layer around Earths
  surface in which life can exist
• Energy Flow in the Biosphere
• Closed system matter cannot leave the Earth or
  enter the Earth
• Open system energy can get into the Earth
  through the atmosphere