My notes

• Earthquake

  The shaking of the ground
• Earthquakes happen when


  1. Crustal plates move

  2. Parts of the earth's crust are pushed toward each other or away from each other

  3. Nearby rocks move and break and slide past each other

  4. Waves of energy are released and sent out through the Earth
• Seismograph


  An instrument that measures the motion of the ground during an earthquake
• Types of earthquakes


  • Volcanic earthquake
  • Tectonic earthquake
• Volcanic earthquake


  Happens with a strong volcanic eruption
• Tectonic earthquake


  Caused by the movement of the earth's crust, may occur above ground or beneath the ocean
• Strong earthquakes or shaking of the ground


  Can loosen the soil and rocks and can cause disastrous landslide and destruction to properties and surroundings above the ground
• Tsunami


  A gigantic wave sometimes 150 km. long traveling at about 180 km/h and increases in height while traveling, rising as high as 30m as it approaches shore
• How a volcanic eruption occurs


  1. Tectonic plates collide

  2. Massive rocks underground deform and trigger a build-up of temperature and pressure

  3. High temperature and pressure results in the melting of rocks, producing magma

  4. Molten rock inside the magma chamber is forcefully driven out by the intense heat and pressure

  5. The release of magma from the crater is called volcanic eruption

  6. The magma that flows out of the surface is called lava

  7. Volcano erupts and throws out lava together with gases, rocks, and ashes
• Region IV-A CALABARZON has numerous volcanoes including Banahaw and Taal
• PHIVOLCS categorized Philippine volcanoes into active volcanoes, potentially active volcanoes, and inactive volcanoes
• Above ground earthquake


  An earthquake that is felt on the surface of the earth, as opposed to one that originates below the earth's crust.
• Tectonic earthquake


  An earthquake caused by the movement of the earth's crust, which can occur both above ground and beneath the earth's crust.
• Earthquake


  A sudden shaking or trembling of the Earth's surface, caused by the movement of tectonic plates beneath the Earth's crust.
• Tectonic plates


  Large pieces of the Earth's lithosphere (crust and upper mantle) that fit together like a jigsaw puzzle.
• Shaking of the ground


  The physical sensation of an earthquake, caused by the seismic waves generated by the movement of tectonic plates.
• Movement of tectonic plates


  The slow, constant movement of these plates due to convection currents in the underlying semi-fluid asthenosphere.