Seismic Waves (T)

• What are seismic waves?

  Seismic waves are energy waves that travel through the Earth, generated by earthquakes.
• What are the two main types of seismic waves?

  P-waves and S-waves.
• Why are seismic waves important for understanding the Earth's internal structure?

  They provide evidence about the internal structure of the Earth.
• What is the structure of the Earth from the outside in?

  • Solid crust (maximum depth of around 50 km)
  • Mantle (solid, with some parts flowing slowly)
  • Outer core (liquid)
  • Inner core (solid)
• How do earthquakes relate to seismic waves?

  Earthquakes generate seismic waves due to sudden movements between tectonic plates.
• What is the role of seismometers in studying seismic waves?

  Seismometers detect seismic waves as they pass through the Earth.
• What type of wave are P-waves?

  P-waves are longitudinal waves.
• What types of materials can P-waves travel through?

  P-waves can travel through both solids and liquids.
• What type of wave are S-waves?

  S-waves are transverse waves.
• What types of materials can S-waves travel through?

  S-waves can only travel through solids.
• How do the speeds of P-waves and S-waves compare?

  P-waves travel faster than S-waves.
• What is the S-wave shadow zone?

  • Area where no S-waves are detected
  • Indicates that S-waves cannot pass through liquids
  • Suggests the Earth has a liquid outer core
• What is the P-wave shadow zone?

  • Area where no P-waves are detected
  • Caused by P-waves slowing down in the liquid outer core
  • Confirms the outer core is liquid
• Why do P-waves refract when entering the outer core?

  Because they travel faster in solids than in liquids, causing them to slow down and refract.
• How did scientists conclude that the Earth has a solid inner core?

  By detecting faint P-waves in the P-wave shadow zone.
• How have scientists used seismic waves to measure the Earth's internal structure?

  • Analyzed seismic waves from thousands of earthquakes
  • Determined the thickness of the crust, mantle, and cores