GMOA Notes

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These are notes that cover Geology, Meteorology, Oceanography, and Astronomy.


Introduction

Earth's four spheres

Hydrosphere - dynamic mass of liquid that is always on the move

  • Oceans - the most prominent feature of the hydrosphere
    • 71% of Earth's surface is covered by ocean which is 97% of Earth's water
    • Only 3% is fresh water - streams, lakes, glaciers and underground supplies
  • Water Cycle - constantly recycles water

Atmosphere

  • Provides us with the air we breath
  • Protects us from the sun's intense heat and radiation
  • Protects us from space

Biosphere

  • Includes all life on Earth
  • Interacts and influences the other 3 spheres

Lithosphere

  • Earth's rigid outer layer called the crust and the upper mantle called the asthenosphere
  • Solid earth consists of 4 layers:
    • core
      • inner, solid core
      • outer, liquid core
    • mantle
    • lithosphere
  • Divisions of Earth's surface
    • continents
    • ocean basins

Sciences

Sciences involved in better understanding the earth integrate chemistry, physics, and biology into the following sciences:

Meteorology - the study of:

  • the atmosphere
  • weather and climate

Geology - the study of the Earth, and is broken into

  • Physical geology
    • minerals
    • rocks
    • Earth processes - mountain building, earthquakes, volcanoes, etc.
  • Historical geology - Earth's origin and it's past
    • physical
    • biological

Oceanography - study of the Oceans

  • Composition and movement of seawater
  • Seafloor topography and sea life

Astronomy - the study of the universe

  • Earth is a tiny object in a vast universe
  • to understand Earth helps us to understand other planets and vice versa

Resources and Environmental Issues

Environment

  • Physical environment (abiotic)
    • water
    • air
    • soil
    • rock
  • Biological - living environment (biotic)

Resources

  • Important environmental concern
  • Include:
    • water
    • soil
    • minerals
    • energy
  • Two broad categories of resources
    • Renewable resources
      • can be replenished
      • Examples: plant (lumber) and wind energy
    • Nonrenewable Resources
      • Fixed quantities
      • Examples: fuels and metals

Environmental Problems

  • Local, regional, and global
  • Human-induced and accentuated
    • Urban air pollution
    • Acid rain
    • Ozone depletion
    • Global Warming
  • Natural Hazards
    • Earthquakes
    • Landslides
    • Floods
    • Huricanes
  • World population pressures - in 30 years population increased from 4 to 7 billion
    • US makes up 6% of that but uses 30% of the annual mineral and energy resources
    • Alternate energy sources needed

Scientific Inquiry

Scientific Inquiry - scientific knowledge is gained through the following systematic steps called the scientific method, (PI-HE-RAC)

Gather facts through observation then ask why?

  • Problem - state the problem
  • Information about the problem
  • Hypothesis (untested best guess as to why)
  • Experimentation
  • Record and Analyze results
  • Conclusion - accept or reject hypothesis

Goal of science is to discover patterns in nature and use knowledge to predict what will happen under certain circumstances

  • Theory - tested and confirmed
  • Law - no known deviations have ever been found

Minerals

A mineral is a naturally occurring crystalline solid with a definite but not fixed chemical composition and ordered atmomic arrangement.

Chemistry and Mineral Terms

Chemistry Terms:

  • Chemical Property - characteristics of a material, which depends upon how the material reacts with other materials
  • Element - matter made up of atoms that are essentially all the same and cannot be subdivided by ordinary chemical methods
  • Atom - smallest part of an element
  • Nucleus - central part of an atom made up of protons and neutrons
  • Protons - subatomic particles with a positive charge
  • Electrons - subatomic particles with a negative charge
  • Neutrons - subatomic particles with a charge of 0
  • Atomic number - the number of protons in an atom (above element symbol on periodic table)
  • Atomic mass - the number of protons plus the number of neutrons (below element symbol on periodic table)

Subatomicparticles.gif

  • Isotope - change in the number of neutrons in an atom. Example, and isotope of sodium may have 10 or 12 neutrons
  • Electron Configuration - how the electrons are arranged around the atom in energy levels
    • 1st energy level has 2 electrons
    • all other energy levels have 8 electrons

Electron shell 011 Sodium.svg.png

  • Ion - change in the number of electrons
    • Atoms are most stable with 8 electrons in the outer energy level
    • Will share, lose, or gain electrons to achieve this
  • Ionic bonding - transfer of electrons
    • example - Sodium and Chlorine
  • Lewis Electron Dot Structure - Short hand for showing "chemistry" activity in the outer level by showing the number of electrons in the outer energy level

Lewis.png

  • Covalent bonding - sharing of electrons. VERY STRONG BOND
    • example - bond between Hydrogen and Oxygen
  • Metallic bonding - electrons do not belong to any particular nucleus, they float between nuclei
    • example - two metals touching for a long time can "weld" to each other by metallic bonding. You can increase the speed of this by adding heat.


Mineral Terms:

  • A mineral is a naturally occurring crystalline solid with a definite but not fixed chemical composition and ordered atomic arrangement
    • Size of the ion is important because ions that are within 10% of the same size may be substituted in many minerals. This is why minerals of the same type have different chemical compositions.
      • examples - Si,Al; Fe,Mg; Na, Ca
The main elements in the Continental Crust
Element % by Weight
Oxygen, O 47
Silicon, Si 28
Aluminum, Al 8
Iron, Fe 6
Calcium, Ca 4
Sodium, Na 3
Magnesium, Mg 2
Potassium, K 2
  • Mineral formation
    • Melting - Volcanic activity
    • Evaporation - Salt water: Halite, Gypsum
    • Biological activity - sulfur producing bacteria
    • Oxidized - comes into contact with oxygen: Limonite
    • Leached - as water moves through the soil it dissolves elements. A leech line forms due to mineral formation where the water stops: bauxite
    • Metamorphic processes - formed by heat and pressure. Examples: graphite, chlorite, diamonds. Alters chemical composition and structure, called recrystallization
  • Mineral Types
    • Native minerals - contain one element
      • examples - graphite, C; Copper, Cu; Sulfur, S
    • Sulfides and Sulfates - contain Sulfur and other elements
    • Silicates - contain silicon and other elements
    • Oxides - contain oxygen and other elements
    • Carbonates - contain CO and other elements
      • will effervesce in the presence of an acid
    • Phosphate - contains PO and other elements
  • Physical Property - is controlled by the chemical properties of a material...how its bonded can determine the hardness and the type of impurities that are present in its change in color
  • Color - reflected light; very poor indicator of the true color due to impurities
  • Streak - true color of the mineral found by powdering it. This is found by scratching the mineral across a streak plate.
  • Hardness - the resistance to scratching