Volcanoes Flashcards
What are the three types of Volcano
Active-recently erupted
Dormant- has erupted in last 20” years but not recently
Extinct- unlikely to ever erupt again
What is a composite volcano made up from?
Erupted ash and lava that’s hardened into layers. This Lava is thick so flows slowly and hardens forming steep sides
What is an example of composite volcano?
Mount Fuji in Japan
Where are composite volcanos found?
Destructive margins- eruptions not often but violent
Where can volcanoes be found?
Destructive and constructive margins, hot spots (Pacific ring of fire)
What is a shield volcano made up from?
Only lava, lava is runny so flows fast and spreads wide forming a low flat volcano
What is an example of a shield volcano?
Mount Lou on Hawaii
Where is a shield volcano often found?
Constructive margin
How are volcanoes formed at constructive margins?
Convection currents in the mantle
Plates move apart
Magma rises through gaps forming volcano
How are volcanoes formed at destructive plate margins?
Oceanic plate goes under continental plate as its more dense and is destroyed in the mantle (subduction zone)
Magma forms and rises through cracks in crust called vents lava erupts on surface forming volcano
What are the advantages of living in an area of volcanic activity?
Tourism
Geothermal energy
Metals like iron
Fertile soil can be used to grow crops such as oranges (mt Vesuvius in Italy)
Disadvantages of living in an area of volcanic activity?
Air pollution from eruptions (sulphur)
Gases given off can suffocate people
Dust from eruption kill crops
Pyroclastic flows destroy things
How can we predict volcano eruptions?
Use tilt meter to measure change in slopes
Use seismograph to measure mimi earth quakes
Look for bulges
Measure gas e.g. Sulphur dioxide being released
