Earth's Internal Structures

• The structure of the earth is divided into four major components: the crust, the mantle, the outer core, and the inner core.
• Identify the parts

  A) Oceanic crust

  B) Continental crust

  C) Astenosphere

  D) Mantle

  E) Outer core

  F) Inner core

  
• Layers of the Earth

  1. Crust
  2. Mantle
  3. Core
• Crust - thinnest and outmost layer of the earth where life exist

  • Has continental crust that makes up the continents
  • Mostly made up of aluminum silicate
• Lithosphere

  • lithosphere is the solid, outer part of Earth
  • The lithosphere includes the brittle upper portion of the mantle and the crust, the outermost layers of Earth's structure
  • made up of tectonic plates
• Asthenosphere - just below the lithosphere

  • This layer is responsible for the movement of tectonic plates and plays a crucial role in the process of plate tectonics.
  • soft weak layer that contains magma
  • capable to flow; facilitates movements of lithospheric plates
• Mantle - The layer of the Earth's crust that is above the core

  • semi-solid, rocky and very hot layer.
  • 80% of the Earth's volume and 68% of the mass
  • Top part 900C and lower part 1000C
• Core - responsible for the earth's magnetic characteristics
• 1. Inner Core:

  • Location: The inner core is located at the center of the Earth.
  • Composition: It is believed to be primarily composed of solid iron and nickel due to high pressure despite extremely high temperatures.
  • Size: The inner core has a radius of about 1,200 kilometers.
  • State: The inner core is solid due to high pressure, even though temperatures are extremely high (estimated around 5,700 degrees Celsius).
• Outer Core:

  • Location: Surrounds the inner core and is located beneath the mantle.
  • Composition: The outer core is primarily composed of molten iron and nickel.
  • Size: The outer core extends from the bottom of the mantle to about 2,300 kilometers below the Earth's surface.
  • where magnetic fields are created
  • only layer that is liquid
• Pressure freezing - refers to the phenomenon where a material remains solid at very high temperatures due to the immense pressure exerted on it
• Interface bounderies

  1. Conorod Discontinuity - The boundary between the upper crust and lower crust
  2. Repiti Discontinuity - The boundary between the upper mantle and lower mantle.
  3. Mohorovičić Discontinuity (Moho) - The boundary between the Earth's crust and the underlying mantle. discovered by Andrija Mohorovicic
  4. Gutenberg Discontinuity - The boundary between the Earth's mantle and the outer core.
  5. Lehmann Discontinuity - The boundary between the Earth's outer core and inner core.
• Seismometer - a highly sensitive instrument that detects seismic waves.
• Seismograph - A device that records the vibrations of the ground during an earthquake.
• P-waves - Primary or compressional waves that travel faster than other types of seismic waves because they can pass through solids as well as liquids.
• Body waves - waves that can pass the inner part of the earth
• Secondary waves - transverse waves that moves through solids.
• Surface waves - travels only on the crust

  •do not penetrate inner layers

  •slower than body waves
• Types of waves

  • Love waves

  • Rayleigh waves
• Love waves - fastest type of surface waves

  • move from side to side, most damaging

  • discovered by August Love

  Rayleigh waves - moves in circular manner

  • causes building to move up & down and side to side

  • name after Lord Rayleigh

  • waves with greater devastation
• Continental Drift Theory


  Theory that explains how continents shift position on Earth's surface.
• Alfred Wegener

  Proponent of Continental drift theory. Thought that all the continents were once joined together in an "Urkontinent" before..
• Pangaea

  Supercontinent

  "All and Gaea"
• Panthalasa

  "All seas"

  Vast superocean
• Tectonics


  Branch of geology that deals with movements that shape the Earth's crust.
• Lithospheric plates - moving of irregularly shshaped slabs that fit together to form the surface of the EarthsEarths crust.
• Subduction - process in which denser crust lounges/goes back to into the inner part of the Earth.
• Plate bounderies

  • Divergent Plate boundery - two plate move away from each other.

  • Convergent plate boundery - moving towards each other

  1. Continental-Continental
  2. Oceanic-Oceanic
  3. Continental-Continental

  • Transform plate boundery - Plates slide against one another in opposite directions.
• Convection Current - process where the hot less dense material rise and cool more dense material sink.
• Earthquake - a weak voilent shaking of the griund produced by the sudden movement of rock materials below the Earth's surface.
• Focus - is the point inside the Earth where the earthquake started sometimes called hypocenter.
• Epicenter - point on the surface of the earth directly above the focus.
• Intensity - The strength of an earthquake as percieved and felt by people in a certain locality.
• Magnitude - proportional to the energy released by an earthquake at the focus.
• Seismograph records magnitude and is invented by John Milne. Represented by arabic numbers.
• Richter Magnitude Scale - common standard of measurement of earthquake.

  Invented by Charles Richter.
• Movement Magnitude scale - measure of earthquake based on its seismic moment. Defined by Thomas Hanks.
• Two types of Earthquakes

  • Tectonic Earthquakes

  • Volcanic Earthquakes
• Tectonic Plates - smaller sections of the lithosphere.
• Plate bounderies - edges that separates tectonic plates.