Tectonic Plates

• The lithosphere is the solid outer layer of the earth, including the crust and upper mantle
• The theory of plate tectonics states that Earth's outer layer - the lithosphere - is divided into more than 15 massive pieces called tectonic plates. These plates move around on the asthenosphere (upper mantle), interacting at boundaries, shifting the continents and producing new landforms.
• In 1912, German meteorologist Alfred Wegener published his theory on continental drift. He proposed that the continents had once been joined in one large landmass that he called Pangaea. Over time, this landmass split apart and the continents moved to their current positions. 

  Evidence 

  • how the continental shelves of continents fit together like pieces of a jigsaw 
  • identical rock formations on either side of the Atlantic Ocean 
  • identical plant and animal fossils on different continents separated by oceans.
• Seafloor spreading

  Molten rock rises up from the mantle at the mid-ocean ridges and solidifies to form a new oceanic lithosphere.     

  Evidence

  • Rift valleys along mid-ocean ridges
  •  Magnetic striping: 
  •  Depth of sediments: 
  • Age of the sea floor.     

  Subduction: when one tectonic plate moves underneath another 

  Evidence: Ocean trenches, Earthquake locations, Volcano chains over such activity
• Convergent boundary: where two tectonic plates are moving towards each other, forming fold mountains.
• Divergent boundary: where two tectonic plates are moving away from each other, resulting in oceanic features like the mid-ocean ridge and continental features like rift valleys and volcanoes.
• Transform boundary: where two tectonic plates are sliding past one another.
• Fault: a break in Earth's surface where blocks of rock slide past each other.
• Slab pull: When a denser plate moves under another plate (subduction) at a convergent plate boundary, it will start to pull the rest of the plate along with it, caused by gravity.
• Ridge push happens at mid-ocean ridges, when magma rises up and forms a new lithosphere, which sits higher than the old one and so gravity causes it to slide downhill, pushing the old lithosphere in front of it.
• Convection is a way of transferring heat.
• A convection current is the movement of material from a hot area to a cool area and back again.
• Earthquakes are caused by a build-up of pressure and the release of energy in Earth's crust, most happening along the boundaries of the tectonic plates but also occurring within a plate.
• A fault is the name given to a part of the Earth's surface where blocks of rock slide past each other, which can be as large as a tectonic plate boundary or much smaller.
• Epicenter: the point on Earth's surface directly above the focus of an earthquake.
• Focus: the origin of an earthquake.
• Seismic wave: a wave of energy that passes through Earth's layers and is caused by an earthquake.
• Convergent boundary: where two tectonic plates are moving towards each other, forming fold mountains.
• Divergent boundary: where two tectonic plates are moving away from each other, resulting in oceanic features like the mid-ocean ridge and continental features like rift valleys and volcanoes.
• Transform boundary: where two tectonic plates are sliding past one another.
• Fault: a break in Earth's surface where blocks of rock slide past each other.
• Slab pull: When a denser plate moves under another plate (subduction) at a convergent plate boundary, it will start to pull the rest of the plate along with it, caused by gravity.
• Ridge push happens at mid-ocean ridges, when magma rises up and forms a new lithosphere, which sits higher than the old one and so gravity causes it to slide downhill, pushing the old lithosphere in front of it.
• Convection is a way of transferring heat.
• A convection current is the movement of material from a hot area to a cool area and back again.
• Plate boundaries 

  • convergent boundary:  where two tectonic plates are moving towards each other

  Forms fold mountains

  • divergent boundary:  where two tectonic plates are moving away from each other 

  Oceanic: mid-ocean ridge Continental: rift valley and volcanoes

  • transform boundary:  where two tectonic plates are sliding past one another 

  Fault:  a break in Earth's surface where blocks of rock slide past each other
• Earthquakes are caused by a build-up of pressure and the release of energy in Earth's crust, most earthquakes happen along the boundaries of the tectonic plates, but they can also happen within a plate.
• A fault is the name given to a part of the Earth's surface where blocks of rock slide past each other, faults can be as large as a tectonic plate boundary or much smaller.
• Epicenter: the point on Earth's surface directly above the focus of an earthquake.
• Focus: the origin of an earthquake.
• Seismic wave: a wave of energy that passes through Earth's layers and is caused by an earthquake.
• • Slab pull: When a denser plate moves under another plate (subduction) at a convergent plate boundary, it will start to pull the rest of the plate along with it. Caused by gravity. 
  • Ridge push happens at mid-ocean ridges. When magma rises up at a mid-ocean ridge, it forms a new lithosphere. This new lithosphere sits higher than the old one and so gravity causes it to slide downhill, pushing the old lithosphere in front of it.
• Convection is a way of transferring heat.
• A convection current is the movement of material from a hot area to a cool area and back again.
• Earthquakes are caused by a build-up of pressure and the release of energy in Earth's crust.
• Most earthquakes happen along the boundaries of the tectonic plates, but they can also happen within a plate.
• A fault is the name given to a part of the Earth's surface where blocks of rock slide past each other.
• Faults can be as large as a tectonic plate boundary or much smaller.
• Epicenter: the point on Earth's surface directly above the focus of an earthquake
• Focus:  the origin of an earthquake