Changes due to Earthquakes

• Volcanic eruption


  Changes on the Earth's surface due to volcanic activity
• Volcanic eruption


  When tectonic plates collide, massive rocks underground form and trigger a build-up of temperature and pressure, resulting in melting of rocks and producing magma
• How a volcanic eruption occurs

  1. Tectonic plates collide

  2. Massive rocks underground form

  3. Temperature and pressure build up

  4. Rocks melt, producing magma

  5. Magma in chamber is forcefully driven out
• Volcanic eruption


  1. Magma chamber

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

  3. Release of magma from the crater is called a volcanic eruption

  4. Magma flows out on the surface as lava

  5. Volcano erupts, ejecting lava, gases, rocks, and ashes
• Magma


  Molten rock that flows out on the surface during a volcanic eruption
• Pyroclastic materials


  Lava, ashes, volcanic glass, and rocks ejected by the volcano into the air
• Volcanic eruption


  • Can be explosive or nonexplosive
  • Explosive eruption occurs when gases in the magma are trapped, causing a build up of pressure in the magma chamber, resulting in a violent explosion
  • Nonexplosive eruption occurs when lava just flows out of the crater and gaps along the sides of the volcano, due to less pressure in the magma chamber
• Volcanic eruption


  • Can be explosive or nonexplosive
  • Explosive eruption occurs when gases in the magma are trapped, causing a build up of pressure and violent explosion
  • Nonexplosive eruption occurs when lava just flows out with less pressure in the magma chamber
• Volcanoes


  • Vary in sizes, from low-lying depressions to tall mountains
  • Vary in shape, from cone-shaped to dome-shaped
• Volcanoes


  • Vary in size from low-lying depressions to tall mountains
  • Vary in shape from cones to domes
• Volcanic eruptions can cause damage to plants, animals, people, and property
• Effects of volcanic eruptions

  • Destruction of plants, animals, people, and property
  • Lava flow can burn anything in its path
  • Mudflow or lahar can cause landslides, flooding, and damage
  • Volcanic ash and dust can irritate lungs and cause health problems
  • Can trigger earthquakes
• Beneficial effects of volcanic eruptions

  • Pyroclastic materials can make soil fertile
  • Fumaroles can provide geothermal steam for electricity generation
  • Can produce industrial materials like pumice and sulfur
  • Rocks help scientists study the Earth's interior
• Hot lava flow can burn anything in its path, mudflow or lahar can cause landslides, flooding, and damage to buildings and farms, volcanic ash and dust can irritate lungs and cause health problems, strong eruptions can trigger earthquakes
• Volcanic eruptions can also be beneficial, as the pyroclastic materials can make the soil fertile, the heat can produce geothermal steam to generate electricity, and eruptions can produce industrial materials like pumice and sulfur
• Rocks from volcanoes help scientists study the interior of the Earth