earth

• Layers of the Earth

  • Discontinuities in the layers of the earth
  • Position, Density, and Composition

  
• Layers of the Earth

  • Crust
  • Mantle
  • Core

  
• Rock


  A solid collection of mineral grains held together in a solid mass, and they are majorly classified by how they are sourced and formed
• Types of Rocks


  • Igneous Rocks
  • Sedimentary Rocks
  • Metamorphic Rocks

  
• Rock Cycle


  A web of processes that outlines how each of the three major rock types—igneous, metamorphic, and sedimentary—form and break down based on the different applications of heat and pressure over time

  
• Mineral

  Naturally occurring, solid at room temperature, inorganic, fixed chemical structure
• Mineral Properties


  • Luster
  • Hardness
  • Streak
  • Cleavage
  • Specific Gravity
  • Color
• Mineral Classifications


  • Silicates
  • Non-silicates (Carbonates, Halides, Oxides, Sulfides)
  • Native Elements
• Landform


  A feature on Earth's surface that is part of the terrain, including mountains, hills, plateaus, plains, and minor landforms like buttes, canyons, valleys, and basins
• Waterforms / Waterways


  • Ocean
  • Sea
  • Strait
  • Gulf
  • Bay
  • Lake
  • River
  • Tributary
  • Spring
  • Lagoon
  • Waterfall
• Stratigraphy


  The study of rock layers and layering (stratification)

  
• Principles of Stratigraphy


  • Catastrophism
  • Uniformitarianism
  • Law of Superposition
  • Law of Lateral Continuity
  • Law of Original Horizontality
  • Law of Cross-Cutting Relations
  • Faunal Succession
• Fossils


  Preserved remains or traces of organisms from the past
• Geologic Time


  • Formation of the Earth (4.6 BYA)
  • Cambrian explosion (530 MYA)
  • Holocene (11.8 KYA - Present)

  
• Absolute Dating


  Gives numerical age (e.g. 200 ± 3 million years)
• Relative Dating


  Arranges objects/organisms/events in time (which one is older/younger)
• Plate Tectonics


  Earth's crust and rigid upper mantle are broken into enormous slabs called tectonic plates that interact at their boundaries

  
• Plate Boundaries


  • Divergent
  • Convergent (Oceanic-Oceanic, Oceanic-Continental, Continental-Continental)
  • Transform

  
• Volcanoes


  Fueled by magma, which is a molten or semi-molten natural material formed by the heating of the Earth's crust and mantle
• Convection currents


  Cause plates to move
• Divergent boundary


  • Plates move apart

  
• Convergent boundary


  • Plates come together (oceanic-oceanic, oceanic-continental, continental-continental)

  
• Transform boundary


  • Plates slide horizontally past each other

  
• Magma


  A slushy mixture of molten rock, mineral crystals, and gases
• Lava


  Magma that reaches the Earth's surface
• Most of Earth's active volcanoes are located along plate boundaries

  
• Shield volcanoes


  • Largest of the three types, long gentle slopes, composed of layers of solidified basaltic lava, quiet eruptions

  
• Cinder cones


  • Smallest of the three types, steep-sloped cone-shaped, usually composed of basaltic lava, explosive eruptions, usually form at edges of larger volcanoes

  
• Composite volcanoes


  • Considerably larger than cinder cones, tall majestic mountains, composed of layers of granitic rock and lava flows, cycle through periods of quiet and explosive eruptions

  
• Types of magma


  • Basaltic
  • Andesitic
  • Rhyolitic
• Stress


  Total force acting on crustal rocks per unit area (compression, tension, shear)

  
• Strain


  Deformation of materials in response to stress
• Faults


  • Any fracture or system of fractures along which Earth moves, they form when the forces acting on rock exceed the rock's strength
• Types of faults


  • Reverse (compression), Normal (tension), Strike-slip (shear)
• Seismic waves


  Vibrations of the ground during an earthquake
• Types of seismic waves


  • Primary waves (P-waves), Secondary waves (S-waves), Surface waves
• Focus


  Point of initial fault rupture, point where waves originate
• Epicenter


  The surface point directly above the focus
• Seismometer


  A sensitive instrument used to detect vibrations caused by seismic waves
• Seismogram


  The record produced by a seismometer