Volcanoes Flashcards
Which plate boundaries have volcanoes?
Constructive (divergent) plate margins and destructive (convergent) plate margins
What is an example of constructive boundary?
Mid-Atlantic ridge
What are 3 examples of destructive boundaries?
Oceanic-Oceanic
Oceanic-Continental
Hot spots/Mantle plumes
Which plate boundaries don’t have volcanoes?
Conservative
Continental-continental
Where are shield volcanoes found?
Constructive/divergent margins
Where are stratovolcanoes found?
Destructive margins
What hazards are found at constructive margins?
Lava,Volcanic gas
What type of lava is found at constructive margins?
Basaltic lavas
What type of eruption is found at constructive margins?
Gentle or non-explosive
What is the frequency of eruptions like at constructive margins?
Very frequent
What type of volcanoes are found at constructive margins?
Shield volcanoes or fissure eruptions
What are 2 examples of places that are constructive?
Iceland
East African Rift valley
What hazards are found at destructive margins?
Pyroclastic flows, ash fall, lahars, volcanic gases, landslides etc
What is the lava type at destructive margins?
Andesitic/Rhyolitic lavas
What is the eruption type at destructive margins?
Explosive
What is the frequency of the eruptions at destructive margins?
Infrequent
What volcanoes are found at destructive margins?
Composite/ Stratovolcanoes
What hazards are found at oceanic mantle plumes?
Lava and volcanic gases
What hazards are found at continental mantle plumes?
Pyroclastic flows, ash fall, lahars and climate change
What is the lava type found at oceanic mantle plumes?
Basaltic
What is the lava type found at continental mantle plumes?
Andesitic/Rhyolitic lavas
What is the eruption type and frequency at oceanic mantle plumes?
Non-explosive but very frequent
What is the eruption type and frequency at continental mantle plumes?
Explosive but non frequent
What volcanoes are found at oceanic mantle plumes?
Shield volcanoes
What volcanoes are found at continental mantle plumes?
Calderas
How can volcanic hazards be managed?
Preparedness
What is 2 signs of a volcano may be about to erupt?
An increase in various gases
A rise in the level of lava lakes
Name 3 ways people try to mitigate the effect of volcanic activity?
Risk assessments
Diversion
Barriers
What are risk assessments for volcanoes?
Governments of countries carry out risk assessments and produce a series of alert levels to warn the public of the threat
What are barriers for volcanoes?
Barriers can be built across valleys to protect property from lava flows
What is the most common way to reduce the impact on people?
Evacuate vulnerable areas when risk becomes intolerable
