Periodical

• 1. Magma refers to the molten materials that are still inside the volcano. Lava is the molten material that reaches the earth’s surface.
• Composite volcano


  • High elevation and small base
  • Made of alternating layers of lava flows, volcanic ash, and cinders
• The shape of a volcano

  Can determine its magma emission
• Active volcanoes


  Volcanoes that erupt often and in erupted in recent times
• Volcanic eruption


  An event that happens when hot lava, ashes, and gases are discharged from a volcanic vent
• Kanlaon in Negros Occidental is an active volcano
• Volcanoes in the Philippines are found in different locations
• Inactive volcanoes


  Volcanoes that have not erupted in the last 10,000 years
• Vulcanian eruption


  • Characterized by tall eruption columns that reach up to 20 km high with pyroclastic flow and ash fall
• Viscosity of magma


  Depends upon its silica content and its temperature
• Signs of impending volcanic eruption

  • Crater glow due to presence of magma at or near the crater
  • Increase in the frequency of volcanic quakes with rumbling sounds; occurrence of volcanic tremors
  • Increase steaming activity; change in color of steam emission from white to gray due to entrained ash
• A thick layer of volcanic ash can be heavy enough to collapse the roofs of buildings because ash is consist of tiny fragments of rocks that becomes heavy as they pile up
• Characteristics that determine the explosiveness of a volcano

  • Viscosity of magma
  • Temperature of magma
  • Silica content of magma
• Reasons why people near a volcano need to evacuate before it erupts

  • Hot lava can spew out in gentle streams or can erupt violently into the air
  • Death and serious injury to people and animals may result from burns and inhalation of hot ash and gases
  • The extreme temperature of rocks and gas inside pyroclastic flows can cause combustible material to burn
• Geothermal power plant

  1. Hot water

  2. Steam

  3. Turbine

  4. Generator

  5. Electricity
• The first geothermal power plant in the Philippines is located in Leyte
• Geothermal energy is an example of renewable energy source
• One of the advantages of using geothermal energy is that it is not dependent on the weather conditions
• Magma with high silica content


  Tends to be very viscous
• Geothermal

  Comes from the Greek word "geo" and "thermal" which means earth and heat
• Climate


  The condition of the atmosphere in a place over a long period of time
• Some of the Philippines geothermal power plants

  • Tiwi
  • Bacman
  • Makban
• The Philippines is a good place to build geothermal power plant because it is in the Pacific Ring of Fire
• Precipitation happens when the rate of evaporation is equal to the rate of condensation
• As the altitude increases

  Air temperature decreases
• Places at the same latitude but in different altitudes have different climates because higher altitudes have lower temperature
• The windward side of a mountain often receives the most precipitation
• Baguio City has a cold weather because of its high altitude
• Stars appear to move in the sky because the earth is rotating
• The constellation Cygnus is visible to an observer in Manila in September but not visible in March because the Earth orbits the Sun
• Constellations


  Grouping of stars in the sky
• Blue stars are the hottest while red stars are the coolest
• The color of the stars is due to their varied temperatures
• Buwaya is the local name of the constellation that signifies the start of rainy season
• Polaris, the North star, helps sailors to navigate the sea
• Sirius appears to be the brightest star based on its apparent magnitude
• Cloud formation in the leeward side of a mountain disappear as the air moves slowly because the amount of water vapor is not enough on that side
• The greenhouse gases can cause global warming because they prevent heat to escape from earth
• Human activities that can contribute to global warming

  • Illegal fishing
  • Mining activities
  • Incineration of garbage
• Organic farming can reduce the effect of climate change