Volcanoes

Question 1

Explain the formation of a volcano

Answer 1

• Destructive Plate Boundary
• Continental crust plate moves towards an oceanic crust plate
• The oceanic crust is forced underneath the continental crust
  because it is heavier
• This generates a lot of heat and friction causing the crust to melt
• Some of the molten rock can be forced to the surface of the earth,
  forming a volcano
• Constructive Plate Boundary
• two tectonic plates move in opposite directions and this creates an
  opening in the earth crust
• magma then rises up through the opening creating new oceanic
  crust
• this new land can then surface above the water and form islands,
  e.g. Iceland

Question 2

Explain the impact on people of a volcanic eruption you have studied

Answer 2

• Mt ST Helens
• 57 people killed
• Settlements, including logging cabins destroyed
• Loss of crops and farmland equal to $100 million
• Airline flights cancelled
• Telephone and electricity lines knocked
• 15 miles of railway destroyed
• People had to be evacuated

Question 3

Explain the impact on the landscape for a volcanic eruption you have studied

Answer 3

• Mt ST Helens
• 7000 animals killed including bears and elk
• Height of mountain dropped by 390m
• Loss of 250 km of Spirit Lake
• Toutle River buried
• Every tree in 250km flattened
• Loss of fertile soil
• Ash clogged rivers

Question 4

Explain the management strategies used for a volcanic eruption you have studied

Answer 4

• Mt ST Helens
• Measure for gas releases such as Sulfur Dioxide
• Tiltmeters are used to measure the ground tilt or gradient near a
  volcano
• Evacuation plans for settlements
• People are educated so they know what to do
• Monitor animal behavior
• Thermal imaging techniques used to check thermal activity
• Emergency services and military are put on standby to help
  trapped/injured people