Tectonic Plates

• Tectonic plates

  • Constant motion & travels a few centimeters every year.
  • Composed of both continental and oceanic crust
• Crust


  Uppermost layer of earth & thinnest

  composed of hard strong rocks because it is relatively cool, contains dark dense basalt.

  humus - decaying organism (reason why crust is dark or brown)
• Mantle


  The layer that lies directly beneath the crust, thickness of 2,900km
• Upper Mantle


  Made up of Fe & Mg but poor in silica, 400 km thick & denser than the crust
• Asthenosphere


  Lies below the lithosphere, part of the upper mantle, layer of weak rocks which extends from about 100-350 km deep, layer where plate floats and involves plate tectonic movements
• Lower Mantle


  Denser than the upper mantle, has a greater amount of Fe
• Core


  Innermost layer of the earth, made up of Fe & Ni, inner core - solid; 1300km, outer core - liquid; 2100 km (made of Fe, na hindi agad natutunaw)
• Geologists estimated that there are 100,00 active and inactive volcanoes on earth
• Earth's Crust


  The boundary between the crust and the mantle, discovered in 1909 by Andrija Mahorovicic, 8 km beneath ocean basins, 32 km beneath continental surfaces
• Mohorovicic Discontinuity


  An increase in the velocity of the seismic waves
• Continental Crust


  Makes up earth's landmasses
• Oceanic Crust


  Found in the ocean floor and is usually thinner than continental crust, forms landforms below the oceans and the seas because it is heavier, denser and darker
• Alfred Wegener


  German meteorologist and geophysicist, formulated the most complete statement of the continental drift hypothesis
• Alfred Wegener's Continental Drift Theory proposed that the continents formed one supercontinent Pangaea and started to drift away
• Evidence for Continental Drift

  • Some types of fossilised animals and plants found in S. Amera and Africa
  • The shape of the east coast of S. America fits the West of Africa
  • Matching the rocks formation and mountain chains found in S. America and Africa are identical
• Convection Current


  Movement of materials caused by the difference in their temperature, the part of the mantle closer to Earth's core is much hotter than the part farther from the core and closer to the lithosphere
• Harry Hess


  Professor of geology at Princeton University, found father of the unifying theory of plate tectonics
• Seafloor Spreading Theory


  Basaltic magma from the mantle rises to create a new ocean floor at mid-ocean ridges, great deal of volcanic eruption and earthquake activity occurs at mid-ocean ridges
• Subduction


  Two plates meet, one plate containing the oceanic lithosphere ascends beneath the adjacent plate
• Magnitude


  Refers to the energy release by an earthquake, indicates amount of energy released of the epicentre, measured by the open-ended richter scale
• Mercalli Scale (Modified)


  Used in NZ, HK, Canada, US
• PEIS


  Phivolcs earthquake intensity scale used in the Philippines
• Seismograph


  Instrument that detects and measure waves, tool used by scientists to detect earthquakes and its strength
• Seismogram


  Record produced by the seismograph, perfected by a British scientist John Milne
• Richter Magnitude Scale


  Device or a standard used by measuring the earthquake, developed by Charles F. Richter of the California Institute of Technology in 1935, mathematical device designed to measure the magnitude of the earthquake in terms of the amount of energy released during an earthquake
• Tidal


  Gravitational interaction between earth & moon
• Tsunami


  Caused by earthquakes of magnitude 7.0 and above
• Storm Surge (Daluyong)


  Caused by atmospheric conditions, low pressure area
• Intensity


  Measures the strength of trembling produced by the earthquake at a certain place, determined from the effects brought on people, buildings and the environment
• Modified Mercalli Scale


  Used by countries like NZ, USA, Canada, Hong Kong, descriptive scale from 1 – 12 based on how people feel an earthquake
• PHIVOLCS Earthquake Intensity Scale


  Used solely by the Philippines, descriptive scale from 1 -7
• October 4, 1957 - Soviet rocket launched Sputnik 1 into orbit around the earth, the USSR dominated space exploration until 1961
• November 3, 1957 - Sputnik 2 was the first such biological spacecraft, sending the dog Laika into orbit
• January 31, 1958: The US successfully launched its first spacecraft – Explorer 1, it discovered the magnetic radiation belts around the Earth called – Van Allen radiation belts
• October 1, 1958: Created NASA from National Advisory Committee for Aeronautics (NACA)
• July 1958: US Congress passed the National Aeronautics and Space Act (Space Act of 1958)
• Jan. 2, 1959: The USSR sent a lunar - Luna 1, the first spacecraft to reach the vicinity of the Moon and the first to leave Earth's gravity
• Sept. 12, 1959: Luna 2 is the first spacecraft to hit the moon's surface
• Luna 3: circled the Moon and recorded the first photographs of the far side of the moon
• April 12, 1961, the dream to travel in space became reality when cosmonaut Yuri Gagarin orbited Earth