SCIENCE Q1

• What is the theory that explains how Earth’s major landforms are created?

  Plate Tectonics
• What does the Plate Tectonics theory state about the Earth's crust?

  It is broken down into several plates that continuously move.
• What is the lithosphere composed of?

  The crust and the upper layer of the mantle.
• Why does the continental crust float higher than the oceanic crust?

  Because of the difference in density.
• What causes the magma in the mantle to move in a cyclic pattern?

  Intense heat in the Earth’s interior.
• What are the two main theories related to plate tectonics?

  • Continental Drift Theory: Movement of crusts and plates.
  • Sea-Floor Spreading Theory: Formation of new oceanic crust through volcanic activity at mid-ocean ridges.
• What is a plate in the context of plate tectonics?

  A continent, parts of a continent, or undersea portions of the crust.
• What are earthquakes?


  Systematic waves created due to the sudden release of energy in the Earth's crust.
• What is seismology?


  The study of earthquakes and the waves they create.
• Who are seismologists?


  Scientists who study earthquakes.
• What are seismic waves?


  Waves created by a sudden vibration released in the Earth’s crust.
• What is a seismogram?


  The recording of the ground shaking at the specific location of the instrument.
• What does intensity measure in the context of earthquakes?

  The amount of Earth-shaking that happens at a given location.
• What does magnitude measure in relation to earthquakes?

  The size of the seismic waves or the amount of energy released at the source of the earthquake.
• What method do seismologists use to locate the epicenter of an earthquake?

  Triangulation method.
• What are P Waves?

  The fastest kind of seismic waves that can travel through solid rocks and fluids.
• What are S Waves?

  Slower than P waves and can only move through solid rock.
• How can the distance between the first P wave and the first S wave help in locating an earthquake's epicenter?

  It tells how far the seismograph is from the epicenter of the earthquake.
• What are the types of surface waves?

  • Love waves: Fastest surface wave.
  • Rayleigh waves: Rolls along the ground, moving it up and down, side-to-side.
• What can underwater earthquakes produce?

  Huge surface waves in the ocean called tsunamis.
• What is the range of tsunami heights?

  From 2 meters to 30 meters tall.
• How do scientists detect and measure earthquake waves?

  Using seismographs.
• What is the epicenter of an earthquake?

  The location where the waves from an earthquake are highly intense.
• What is the hypocenter or focus of an earthquake?

  The location below the Earth’s surface where the earthquake starts.
• How did scientists gain information about the Earth’s internal structure?

  By studying how seismic waves travel through the Earth.
• Who discovered that the velocity of seismic waves changes at a distance of about 50 km?

  Andrija Mohorovicic.
• What is a shadow zone in relation to seismic waves?

  The area where P waves are not detected between 103° to 142°.
• What is the Gutenberg Discontinuity?

  The boundary between the mantle and core.
• Who found out about the Gutenberg Discontinuity?

  Beno Gutenberg.
• What is the Mohorovicic Discontinuity?

  The boundary between the crust and mantle.
• Who discovered the Mohorovicic Discontinuity?

  Andrija Mohorovicic.
• Who predicted the innermost layer of the Earth?

  Inge Lehmann.
• What are plate boundaries?

  • Lines at the edges of different pieces of the lithosphere.
  • Regions where plates are colliding, separating, and moving.
  • Sometimes called "plate margins."
• What does the lithosphere consist of?

  The crust and the upper layer of the mantle.
• What causes lithospheric plates to move?

  Convection currents in the Earth’s interior.
• What are the types of plate boundaries?

  1. Divergent Plate Boundary (Extensional)
  2. Convergent Plate Boundary (Compressional)
  3. Transform Fault Plate Boundary (Shearing)
• What occurs at a divergent plate boundary?

  Plates separate and move apart in opposite directions.
• What is formed at mid-ocean ridges?


  New lithosphere.
• What can trigger volcanic eruptions at divergent boundaries?


  Separation of oceanic crust.
• What happens at a convergent plate boundary?

  Two plates move toward each other and can collide.