hotspots

• example of a place with a hotspot

  hawaii
• how do hot spots prove continental drift

  the series of hawaiin islands each with extinct volvanoes, presumably from the hawaiian hot spot and overtime the volcanoes have moved away from the hotspot and become extinct

  
  

  and with increasing distance away from the hot spot, the islands get older
• how old is hawaii

  0.7m years old (estimated)
• how old is the furthest island from hawaii

  5.6m years old (estimated)
• what is a sea mount

  a submarine mountain

  - perhaps an island which has eroded eg near hawaii after becoming extinct
• how do seamounts form

  due to erosion of a larger island or the pressure on the crust from the island/mountain causes the crust to subside
• how far is hawaii from the nearest plate boundary

  3.2km
• how does hawaii not confirm to the pattern of volcanoes

  the islands are completely volcanic but 3.2km away from nearest plate boundary
• how many volcanoes does hawaii have

  5

  3 are active

  
  

  eg:

  Mauna loa - highest at 4.1km

  Kilauea is the most active on earth
• how thick is the oceanic crust under hawaii

  5km thick
• what is the theory behind hotspots?

  the theory is not conclusive but

  
  

  some believe that they are the result of plumes of magma originating from deep within the mantle

  
  

  but others think they are created at a more shallow depth

  
  

  it is thought that a concentration of radioactive elements inside the mantle may form a hotspot to develop

  - from this, a magma plume rises into the plate above and where the lava breaks the surface a volcano occurs above the hotspot