Tectonic hazards

• In 2015, Japan experienced its most powerful earthquake in over 70 years with a magnitude of 9.0 on the Richter scale.
• conservative plate boundaries occur where plates slide past each other. Faults and earthquakes are common along conservative boundaries.
• destructive plate boundaries occur where plates collide and one plate subducts below another. Subduction leads to volcanic activity and mountain building.
• construcive plate boundaries occur where plates move apart, such as at mid-ocean ridges. New crust is formed and magma from the mantle rises to the surface, creating new seafloor.
• The tohoku earthquake triggered a tsunami that caused widespread damage to coastal areas and resulted in more than 16,000 deaths.
• Japan has implemented measures such as building codes requiring structures to be able to withstand strong seismic activity, early warning systems, and evacuation drills to mitigate the impact of future earthquakes.
• Earthquakes can cause landslides, which are sudden movements of rock or soil downhill due to gravity.
• The San Andreas fault is an example of a conservative boundary between two tectonic plates.
• Earthquakes can cause damage to buildings, roads, bridges, and other infrastructure.
• Tsunamis are large waves generated by underwater earthquakes or volcanic eruptions.
• Plate tectonics refers to the movement of Earth's crust into different positions
• There are three types of plate boundaries: construcive , destructive and conservative
• Volcanoes are mountains built by eruptions of molten rock (magma) from beneath the Earth's surface.
• Volcanoes are mountains built up over time through repeated eruptions of molten rock (magma) and ash.
• Shield volcanoes have gentle slopes and are made up mostly of fluid lava flows.
• Most earthquakes occur along plate boundaries, where plates are moving together, or past each other.
• island chains are formed by a hot spot on the earths crust , where the plate is moving but the hotspot (rising magma) isnt
• Primary hazards of an erruption are: ashfall, pyroclastic flows, lahars, and volcanic gases
• Secondary hazards of an eruption: Destruction of property, loss of life, loss of crops ,landslides ,

  tsunamis
• Primary effects of an eruption: people killed and injured, magma thrown into the air , communications damaged
• Secondary effects of an eruption:

  spread of disease, loss of farmland , food and water shortages, local businesses suffering
• Economic opportunities of living in a volcanically active area: nutrient rich soils for farming, tourism and use of geothermal energy
• Volcanic activity can be measured using a seismograph machine
• A- fault line

  B- seismic waves

  C- epicentre

  D- focus

  
• Earthquakes are measured by the richer scale
• The richer scale measures magnitude
• Focus


  Actual point where earthquake begins
• Epicentre


  Point on earth's surface above the focus where shock waves are strongest
• Shock waves are strongest at the epicentre
• Seismic waves

  Vibration generated by an earthquake which radiates outwards from the focus along the earth's surface
• Fault line


  Long crack in the surface of the earth. Earthquakes usually occur along these lines