Earth Sci

• SCIENCE 10
• E A R T H ' S
• I n t e r n a l S t r u c t u r e
• MS. BEAH S. DE LEON
• THEORY OF
• PLATE TECTONICS

  
• Never be fooled by: 'what you see on the outside because on the inside, it is often a different story.'
• YOUR OUTSIDE WORLD


  IS A REFLECTION OF YOUR INSIDE WORLD.
• What goes on in the inside


  shows on the outside.
• behaviour in response


  of stress
• EARTH'S INTERNAL STRUCTURE

  
• Crust


  • Earth's solid exterior
  • Thinnest layer
  • Represents only about 1% of Earth's planetary mass
  • Made up of the ocean floor and the continents
  • Less dense compare to the rest of the Earth's layers

  
• KINDS OF CRUST


  • CONTINENTAL crust
  • OCEANIC crust

  
• CONTINENTAL crust


  • Forms and contains the large landmasses
  • Consists of granite and basalt
  • Less dense
  • A.k.a. SIAL
  • Older
  • Made of FELSIC rocks

  
• OCEANIC crust


  • Below the ocean
  • Consists of basalt
  • More dense
  • A.k.a. SIMA
  • Formed along mid-ocean ridges
  • Younger
  • Made of MAFIC rocks

  
• LITHOSPHERE


  • Makes up of the crust and upper mantle
  • Rigid and solid
  • Broken into slabs of rocks called plates
  • A.k.a. lithospheric/tectonic plates

  
• LITHOSPHERIC PLATES


  • Seven major plates include the African, Antarctic, Eurasian, North American, South American, Indo-Australian, and the Pacific plates
  • Minor plates include the Arabian, Caribbean, Nazca, and Scotia plates
  • In constant motion

  
• Mohorovijic Discontinuity


  It is the transitional boundary that divides the crust from the mantle.

  
• MANTLE


  • Earth's second layer
  • Largest layer of the Earth
  • Comprises about 80% of the Earth's mass
  • Source of majority of the Earth's internal heat
  • Can be divided into several layers-UPPER MANTLE, TRANSITION ZONE, LOWER MANTLE, CORE-MANTLE BOUNDARY.
• UPPER MANTLE


  • Highly viscous
  • Lies between the crust and lower mantle
  • Consists of peridotite and dunite
  • Extends from the crust to a depth of about 410 kilometers
  • Has 2 distinct regions in the Earth's interior-LITHOSPHERE and ASTHENOSPHERE

  
• ASTHENOSPHERE


  • Denser, weaker layer beneath the lithospheric mantle
  • Contains molten material which act as plastic
  • Extends from the crust to a depth of about 410 kilometers
  • Has 2 distinct regions in the Earth's interior-OUTER AND INNER

  
• TRANSITION ZONE


  • Contains very dense rocks
  • Rocks undergo changes in their crystalline structure
  • Extends from the crust to a depth of about 410 to 650 kilometers
• LOWER MANTLE


  • Also known as Mesosphere
  • Contains denser rocks, less ductile, and semi-solid
  • Extends from the crust to a depth of about 650 to 2,900 kilometers
• CORE-MANTLE BOUNDARY


  • Also known as Guttenberg Discontinuity
  • Contains denser rocks, less ductile, and semi-solid
  • Extends from the crust to a depth of about 2,900 kilometers from the surface of the Earth.

  
• CORE


  • Very dense
  • 15 % of Earth's volume and 33% of Earth's mass
  • Diameter of 6,970 km
  • Has 2 distinct parts: Solid Inner Core and Liquid Outer Core

  
• Earth's Magnetic Field
• A Molten Core
• Carries energy from an earthquake away from the focus, through Earth's interior, and across the surface.
• FOCUS


  The point where energy is released
• EPICENTER


  The point on the Earth's surface directly above the focus of an earthquake
• KINDS OF SEISMIC WAVES

  • Body Waves
  • Surface Waves
• BODY WAVES


  • Move out from the earthquakes focus
  • Travel the fastest of the 3 waves
  • Move through solid and liquid layers of the Earth
  • Push and pull rock creating a back-and-forth; compression and rarefaction
• S WAVES


  • The second waves to hit the seismographs
  • They are transverse waves, which means that the motion is perpendicular to the direction of wave propagation
  • Travel more slowly than P waves but do more damage
  • Can only go through solid rock
• SURFACE WAVES


  • LOVE WAVES shake the surface side-to-side
  • RAYLEIGH WAVES move the surface of the Earth around in a circle, forward and down then back and up