SCI 10 SEMI & FINALS REVIEWER

• Plate Tectonics - moving of lithosphere
• Earth consists of 3 layers

  1. Crust
  2. Mantle
  3. Core
• Plates move slowly but CONSTANTLY
• Earth is broken into numerous pieces called "Plates"
• Lithosphere consists the Crust and the Upper Mantle
• Crust - Made of variety of rocks like Sedimentary, Metamorphic & Igneous; average density of 2.8g/cm³; has a thickness of 5-50km
• Kinds of Crust 

  1. Continental Crust - Thicker but less dense; Forms and contains the large landmasses; Consist of Granite
  2. Oceanic Crust - Below the Ocean; Consist of Basalt; Very Dense
• 7 Large Plates

  1. Eurasian Plate
  2. North American Plate
  3. Pacific Plate
  4. South American Plate
  5. African Plate
  6. Indo-Australian Plate
  7. Antartic Plate
• Convergent Plate Boundary - Moving towards to each other; Philippine plate and Eurasian plate are moving towards to each other
• Divergent Plate Boundary - Moving apart/Moving away to each other
• Transform Fault Plate Boundary - Slide/Grind past each other; Example of this is the SAN ANDREAS FAULT (Hawaii) which is bounded by North American plate & pacific plate
• Crust - Thinnest and outermost layer ot the eart; Extend from the surface to about 32km below.Divided into two:

  1. Continental Crust - made up of silicion, oxygen, aluminum, calcium, sodium, and potassium; has a thickness of 38-40km; less dense(granite)
  2. Oceanic Crust - 7-10km Thick; Found under the Ocean Floor; Dense(Basalt); Heavier than the continental
• Mantle - Extends to abour 2900km from earth; 50% of the earth and volume is about 68%; made of silicon, oxygen, iron and magnesium; outermost rigid shell called "Lithosphere" (50-100km)
• Astenosphere - Beneath the Listhosphere (300-800°c)
• Core - Divided into two layers:

  1. Inner Core - Radius of 1300km; 5000°C temperature; Pressure Freezing
  2. Outer Core - 2900km below the earth; 2250km Thick; Made of iron and nickel; Temperature reach about 2000°C
• Seismic waves -waves that travel through the earth and are caused by earthquake
• Earthquake - A vibrator produced by the rapid release of energy
• In the form of Seismic Waves energy radiates all direction from the focus which is recorded in the SEISMOGRAPHS.
• Types of Waves

  1. Body Waves - travel through interior of the earth
  2. Surface Waves - travel across the surface of the earth
• Two types of Surface waves

  1. Love Wave - A.E.H Love (Augustus Edward Hough Love) a british mathematician; Faster than Reyleigh Wave; Side to Side horizontal motion; case the most damage.
  2. Reyleigh Wave - Named after John William Strutt (Lord Reyleigh); Predicted in 1885; Rolls along the ground; Up&down or side to side; Most of the shaking
• Two types of Body Waves:

  1. P-waves (Primary Waves) - Faster than S-wave; Reaches the detector first; also called COMPRESSIONAL WAVES; backward & forward: compress & expanded; travel through SOLIDS, LIQUIDS, AND GAS
  2. S-waves (Secondary Waves) - Also called SHEAR WAVES; Travels Slower than P-waves; cannot travel though LIQUID; moves shear or transverse wave
• P-Wave - Can travel through Liquid, Solid, Gas
• S-wave - Cannot travel through Liquid
• Seismic Waves- Radiate from the Focus
• Waves bend due to change in Density
• As depth increases, density also increases
• Divergent Boundaries

  • Formation of Rift Valleys & Oceanic Ridges
  • Crust is splitting/moving away from each other
  • Underwater mountain ranges called "OCEANIC RIGDES"
  • 2-20cm/ per year is the spreading rate at those ridge
  • Divergence of South American Plate and African Plate
  • Rift Valleys are associated with the rising of hot materials in mantle
• Divergence Boundary (Oceanic Plates) Geological features

  • Earthquake
  • Creation of new Seafloor
  • Widening Ocean Basin
• Divergence Boundary (Continental Plates)

  Geologic Features

  • Formation of Rift Valley (continental - continental)
  • Earthquake
  • Numerous Faults
• Volatile Material - Water it allows to rise and reach the crush causing volcanic activities
• Convergent Boundaries (Oceanic Crust) Geologic Features

  • Trench (Submarine Valleys) - Deepest part
  • Occurence of Earthquake
• Philippine Trench - With a depth of 10540 Meters
• Shallow Earthquake - 60km of the earth surface

  Intermediate Earthquake - 60km-300km below the earth surface

  Deep Earthquake - 300-700km Below the earth surface
• Converging oceanic plates will cause

  • Formation of Trenches
  • Underwater Earthquake
  • Tsunami(harbor wave)
• Volcanic Island Arc - chain of volcanoes in arc shape ( oceanic - oceanic)
• Sources of molten materials are called - "Mantle Plume"
• Harry Hess & Robert Dietz - suggested an explanation to continental drift theory which is the SeaFloor Spreading
• Hot less dense material rises towards the surface at the Mid Ocean Ridge
• Magma flows out crack and become a new seafloor
• Subducted is faster than Seafloor