Science

• Earthquake


  Shaking of the ground
• What happens when crustal plates move

  1. Plates pushed toward each other or away from each other

  2. Nearby rocks move and break

  3. Waves of energy released and sent out through the Earth

  4. Motion of the ground measured by seismograph
• Types of earthquakes


  • Volcanic earthquake - caused by strong volcanic eruption
  • Tectonic earthquake - caused by movement of earth's crust, can occur above ground or beneath ocean
• Magnitude


  Measure of the amount of energy released by an earthquake from its focus
• Focus


  Break in the ground caused by the pressure of the moving rocks, where the earthquake originates
• Epicenter


  Ground above the focus
• Richter scale used to measure earthquake magnitude
• PHIVOLCS Earthquake Intensity Scale used in the Philippines to measure earthquake intensity
• Philippines frequently hit by earthquakes due to location in Circumpacific Belt/Pacific Ring of Fire
• Earthquakes have caused many casualties and damages in the Philippines
• Exploring what happens when crustal plates move

  Observe a block of styrofoam
• How a volcanic eruption occurs

  1. Tectonic plates collide

  2. Massive rocks underground deform

  3. Temperature and pressure build up

  4. Rocks melt, producing magma
• Magma chamber


  Inside the volcano, where molten rock is located
• Volcanic eruption


  1. Molten rock in magma chamber is forcefully driven out by intense heat and pressure

  2. Magma is released from the crater
• Lava


  Magma that flows out on the surface
• What a volcano eruption throws out

  • Lava
  • Gases
  • Rocks
  • Ashes
• Volcanic eruption


  • Can be explosive or nonexplosive
• Explosive eruption


  1. Large amounts of pyroclastic materials are ejected into the air

  2. Gases in the magma are trapped, causing pressure build up in the magma chamber

  3. Gases expand quickly and explode violently

  4. Results in a loud explosion

  5. Can last for hours or days
• Nonexplosive eruption


  1. Lava just flows out of the crater and gaps along the sides of the volcano

  2. Less pressure in the magma chamber

  3. Magma is located nearer the Earth's surface