Plate Tectonics

• Alfred Wegner in 1912, the theory of plate tectonics suggested that the Earth’s rigid outer layer known as the lithosphere is broken up into 7 very large continental plates and 5 oceanic sized plates
• • These plates were once connected and formed a supercontinent known as Pangea
• These plates move relative to each other at the rate of 5-10 cm per year
• Plates are driven by convection currents within the mantle which is caused by heat from the core
• List three types of evidence

  Fit of the continents, fossil evidence and rock formations and geological structures
• Asthenosphere


  The upper layer of the earth's mantle, below the lithosphere, in which convection currents appear
• Collision Zone


  The area where two continental plates form a collision boundary
• Continental Drift


  The movement of continents resulting from the motion of tectonic plates
• Convection Currents


  Movements of fluid (gases or liquids) caused by a density or temperature difference with a material or container
• Earthquakes


  A violent shaking of the ground due to movement between tectonic plates
• Epicentre


  The ground directly above the focus (origin point) of an earthquake
• Evolution


  A theory stating that all organisms developed from earlier forms during Earth's history
• Extinct


  A species with no living members, which no longer exists
• Fault


  A fracture/zone of fractures between two blocks of rock, namely tectonic plates
• Focus (hypocentre)


  The point where an earthquake originated
• Fossil


  The preserved remains of plants or animals are typically over 10,000 years old
• Geological Time (Scale)


  A representation of time based on the rock record of Earth
• Igneous (rock)


  Rocks formed via the cooling and solidification of molten rock
• Lava


  Molten rock above the crust of the Earth
• Lithosphere


  The crust and solid upper-mantle of the Earth
• Magma


  Molten rock underneath the crust of the Earth
• Metamorphic (rock)


  Rock that has undergone transformation by heat, pressure, or other natural agencies
• Mid-Ocean Ridge


  A seafloor mountain system caused by a divergent boundary
• Plate Boundary


  The location where two plates meet
• Sedimentary (rock)


  Rocks formed by the accumulation and consolidation of mineral and organic fragments
• Seismograph


  An instrument that measures and records details of earthquakes, such as force and duration
• Seafloor Spreading Zone


  A linear line along the seafloor along which magma rises and divergent plate is located
• Subduction Zone


  Where an oceanic plate meets a continental plate and slides beneath it a convergent boundary
• Superposition


  A law or principle stating that, within a sequence of layers of sedimentary rock, the oldest layer is at the base
• Tectonic


  The scientific study of the forces that produce deformation of the rocks that make up the Earth's mantle
• Transform Vault


  A fault along a plate boundary where the motion is predominantly horizontal
• Tsunami


  Giant ocean waves triggered by large geographical events such as large oceanic earthquakes, volcanic eruptions, and onshore landslides
• Volcano


  Openings in the Earth's crust where lava, tephra, and steam erupt onto the surface of the earth
• Disintegration


  Breaking down or separating into smaller parts or fragments
• Consolidation


  Combining or uniting separate elements or particles into a single, more solid entity