Earth Science

• Earth Science 


  The study of the Earth's dynamics, its processes, properties, structure, and relationship with its neighbors in space.
• Geology 


  The study of Earth's materials.
• Oceanography 


  The study of Earth's bodies of water.
• Meteorology 


  The study of Earth's atmosphere.
• Astronomy 


  The study of Earth's celestial bodies.
• 4.543 billion years old


  How old is the Earth?
• Atmosphere 


  Comes from the Greek word "atmos" which means gas and "sphaira" which means globe or ball.
• Atmosphere 


  It makes up all the gasses of the Earth.
• Troposphere 


  It is the lowest layer where the weather forms. It extends about 14.5 km above the Earth's surface.
• Stratosphere 


  The layer where "ozone layer" is found, it protects the Earth from the Sun's harmful UV radiation. It extends about 14.5 to 50 km above the Earth's surface.
• Mesosphere 


  It protects the Earth from the impact of space debris. It extends about 50 to 85 km above the Earth's surface.
• Thermosphere 


  It has charged particles that are affected by the Earth's magnetic field. The particles create the Northern and Southern Lights. It extends about 85 to 600 km above the Earth's surface.
• Exosphere 


  It is the farthest layer of the Atmosphere. It is where satellites lie. It extends about 1000 km above the Earth's surface.
• Geosphere 


  It includes all the soil, rocks, and minerals present in Earth. "Geo" is from a Greek root which means ground.
• Crust


  It is the outermost layer of the Earth. It is made mostly of silicate materials.
• Continental Crust 


  A type of crust that is thicker but less dense.
• Oceanic Crust 


  A type of crust that is thinner but more dense.
• Mantle


  It lies just below the Crust, is made mostly of silicate rocks rich in magnesium and iron. It is about 2900 km thick. It has increasing temperatures at increasing depths.
• Upper Mantle 


  The mantle's layer with the lowest temperature which is soft enough to flow causing the plates of the crust to move.
• Lithosphere 


  Comes from the word "lithos" which means stone, is a thick and brittle layer comprising the entire crust and the uppermost layer of the upper mantle. It has average thickness of 100 to 300 km.
• Asthenosphere 


  At this depth, the temperature and pressure conditions are high enough that rocks become ductile and deform easily. It comes from the word "asthenēs" meaning weak, is a mechanically weak layer consisting of the lower portion of the upper mantle, extending to 660 km.
• Lower Mantle 


  The Mantle's layer with the highest temperature that is in contact with the heat-producing core.
• Mesosphere 


  Comes from the word "mesos" meaning middle, comprised of the lower mantle, reaching 2900 km depth. It is much more stronger and flows with more resistance.
• Core


  It is the source of internal heat because it contains radioactive materials that release energy as they decay into more stable substances. It has a radius of 3400 km, is the innermost layer of the Earth. It us made up of iron and nickel.
• Core


  It is at the center of the Earth and is hotter than Mantle.
• Outer Core 


  It is in liquid form, 2300 km thick composed primarily of molten iron and nickel. The temperature is around 4000-5700 degrees Celsius.
• Inner Core


  It is a solid ball with a radius of 1220 km. It is made up of solid iron and nickel. The temperature is quite high at around 7000 degrees Celsius.
• Biosphere 


  It is comprised of all living things. "Bio" is from the Greek root that means life. It extends to the upper areas and deep parts of the ocean where organisms live.
• Hydrosphere 


  It is composed of all the water on Earth in any form. "Hydro" is a Greek root which means water.
• About 70% of the Earth is covered with liquid water where 97.5% is saltwater and 2.5% is freshwater.
• Naturally Occurring 


  Minerals form by natural geologic processes. Those produced in laboratory or by human intervention are not considered minerals.
• Generally Inorganic 


  Minerals are inorganic crystalline solids, such as ordinary table salt that are found naturally in the ground.
• Solid Substance 


  Minerals such as ice fits in this criterion.
• Orderly Crystalline Structure 


  Minerals are crystalline substances which means their atoms (ions) are arranged in an orderly, repetitive manner.
• The orderly packing of atoms is reflected in regularly shaped objects called crystals.
• Definite Chemical Composition 


  Minerals are chemical compounds having compositions that can be expressed by chemical formula.
• The Physical Properties of Minerals

  • Color
  • Streak
  • Luster
  • Specific Gravity
  • Hardness
  • Cleavage
  • Fracture
  • Tenacity
  • Crystal Habit
• Color


  This depends on the elements which constitute the crystal lattice - the arrangement of atoms in a specific pattern and with high symmetry.
• Streak 


  It is the color of the mineral in its powdered form.
• Luster


  It is the relative differences in the opacity and transparency of a mineral as light is reflected on its surface. This describes the “sparkles” of the mineral surfaces.