tectonic hazards

• Volcanic eruptions occur when molten rock (magma) rises to the surface.
• Earthquakes can cause loss of life, injuries, damage to property, and infrastructure.
• The magnitude of an earthquake is measured using a scale known as the Richter magnitude scale.
• Shield volcanoes have gentle slopes and are built up from many lava flows that spread outwards rather than exploding.
• Tsunamis are large waves caused by underwater earthquakes or volcanoes.
• A tsunami can travel across oceans at high speeds and have devastating impacts on coastal communities.
• Hot spots are areas where magma rises close to the Earth's crust but does not break through it.
• Pyroclastic flow is a type of volcanic eruption characterized by extremely hot gas and ash moving rapidly down the side of a volcano.
• The inner core is solid and is mostly composed of iron.
• The inner core can remain solid because of the extremely high pressures at the centre of the earth. The inner core is estimated to be 6000°C at the boundary. The inner core measures 2442 kilometres across. 
• The outer core is liquid and is composed of iron and nickel. It is located in between the mantle in the inner core. The outer core is 2890 kilometres beneath the Earth's surface. The outer core’s temperature is between 4400°C. And 6000°C.
• The mantle is the thickest layer of the Earth's layers. It is hot dense, semi solid rock and about. 2900 kilometres thick. A mantle is 84% of the Earth. Temperature is between 500 and 900°C at the top of the layer and 4000°C at the border of the core. Convention currents are moving within the mantle.
• The crust is the outermost layer of the earth. The crust is the thinnest layer with ranging between 20 and 30 to kilometres in oceans and 70 kilometres to 80 kilometres in mountainous areas. The crust is broken up into tectonic plates. Continental crust is older than oceanic crust, but oceanic crust is denser. 
• Types of evidence for continental drift

  • Climatic evidence
  • Jigsaw-fit evidence
  • Paleo-magnetic evidence
  • Geological evidence
  • Fossil evidence
• Continental drift

  The process of tectonic plates moving over time, causing the changing relative positions of the continents
• Continental drift was first identified by Alfred Wegener
• Alfred Wegener's theory

  • Climatic evidence
  • Jigsaw-fit evidence
  • Paleo-magnetic evidence
  • Geological evidence
  • Fossil evidence
• Climatic evidence- continents that used to be together have similar climates.  
• Jigsaw-fit evidence- South America looks like it fits perfectly into Africa and Ireland fits into Britain.  
• Paleo-magnetic evidence- Magnets are balanced in lots of places and layers.  
• Geological evidence- we have the same rocks in places from other side of the world.  
• Fossil evidence- we have very old fossils in very separate places. The creatures couldn't have swum across the sea, so the separate places must have been together.