SCIENCE VOLCANOES

• Earthquake


  Weak to violent shaking or trembling ground caused by the sudden movement of rocks below
• Earthquake origin


  • Originate from tectonic plate boundary
• Crust


  Composed of solid materials
• Crust


  • Made from plates (tectonic plates)
  • There are about 20 plates along the surface of earth that move slowly
  • Movement is brought about by the mantle
  • Crust together with the upper mantle from the lithosphere
  • Plates under the ocean are called oceanic plates and the rest are continental plates
• Earthquake occurrence


  1. When two adjacent tectonic plates bump, slide, or slip

  2. When pressure slowly builds up and the force is strong enough, these rocks underground will suddenly break or slip
• Faults


  Lines or cracks in earth surface that are caused by the movement of the plates
• Types of faults

  • Normal
  • Reverse
  • Strike-slip
• Types of earthquakes

  • Tectonic
  • Volcanic
  • Collapse
  • Explosion
• Tectonic earthquake


  Caused by sudden movements along the tectonic faults and plate boundaries
• Volcanic earthquake


  Caused by volcanic earthquakes such as rising lava etc.
• Collapse earthquake


  Small earthquakes that occur in caves
• Explosion earthquake


  Caused by nuclear explosions or chemical materials
• Seismology


  Study of seismic waves or energy waves
• Seismologists


  Scientists that study earthquakes
• Seismologists


  • Use seismograph to detect and record earthquakes
• Seismogram


  Tells how large the seismic waves are
• Types of seismic waves

  • Primary waves (fastest)
  • Secondary waves (only move through solids)
  • Surface waves (last to reach the seismograph)
• Magnitude


  Refers to the size of the seismic waves, measured using the moment magnitude scale (MMS also called Richter scale) represented by Hindu numerals (0-9)
• Intensity


  Strength of the earthquake based on the observed effect, represented by roman numerals (e.g, I,II,IV,IX)
• Aftershock


  Smaller earthquakes within one or two lengths
• Foreshock


  Cannot be called a foreshock unless a larger earthquake in the same location happens
• July 27 2019 - Batanes struck by a 5.9 magnitude earthquake with a 5.4 foreshock
• PHIVOLCS - Philippine institute of volcanology and seismology - operates 101 seismic monitoring stations all over the country
• DRC - data receiving center - determines the earthquake's magnitude
• Volcanic eruption


  A phenomenon
• Volcano


  Opening in a earth's crust, erupts when pressure builds up, can be a hill or a mountain where hot molten rocks with gaseous materials are ejected
• Philippines is situated on the boundaries of two tectonic plates - Philippine sea plate and Eurasian plate
• Types of volcanoes


  • Cinder cone volcanoes
  • Composite volcanoes
  • Shield volcanoes
  • Lava dome volcanoes
• Cinder cone volcanoes


  Have circular or oval cones made up of fragments or particles, cannot get more tall than 300 meters
• Composite volcanoes


  Have steep sides although they are shaped like cones, can be as tall as 2.4 kilometers
• Shield volcanoes


  Look like a bowl or a shield with long gentle slopes made from lava, lava that flows from these volcanoes is called flood basalts
• Lava dome volcanoes


  Formed by thick lava which makes a steep-sided mound as lava piles up near the vent
• Active volcano


  Recently erupted or has had at least one eruption for the last 10,000 years
• Active volcanoes in the Philippines

  • Mt. Kanlaon in Negros islands
  • Mt. Pinatubo in Zambales
  • Taal volcano in Batangas
  • Mt. Mayon in Albay Bicol (erupted 48 times, first recorded in 1616, worst eruption on Feb 1 1814 killed 1,200 people and destroyed Cagsawa Church)
• Dormant or inactive volcano


  Once an active volcano that has not erupted for 10,000 years but still has the potential to erupt again
• Extinct volcano


  Volcano is no longer expected to erupt again
• PHIVOLCS has been monitoring 23 active volcanoes in the Philippines which may increase in numbers because the country is positioned at the Pacific Ring of Fire which is a 40,000-circle of interconnected fault lines around the Pacific Ocean
• Earthquakes and Volcanic eruptions happen frequently in the Pacific Ring of Fire area, which has 452 volcanoes, making up 50% of the world's active and dormant volcanoes, and 90% of the world's earthquakes happen along this area
• Volcanologist


  Scientists who study volcanoes and their activities, the name of their study is volcanology
• Plate tectonic theory


  Explains the phenomena of volcanoes and earthquakes, convection in the mantle causes the movement of the plates, when the continents collide, with one plate going under the other, it may form a volcano or a mountain range