Major Extrusive Flashcards
What is the silica content of andesitic lava? (Major extrusive tectonics)
Medium
What is the silica content of rhyolitic lava? (Major extrusive tectonics)
High
What is the viscosity of basaltic lava? (Major extrusive tectonics)
Low (runny)
What is the viscosity of andesitic lava? (Major extrusive tectonics)
Medium
What is the viscosity of rhyolitic lava? (Major extrusive tectonics)
High (thick)
What is the temperature of basaltic lava? (Major extrusive tectonics)
1,110-1,200 degrees
What is the temperature of andesitic lava? (Major extrusive tectonics)
750-950 degrees
What is the temperature of rhyolitic lava? (Major extrusive tectonics)
Less that 750 degrees
What sort of lava produces the most violent eruption? (Major extrusive tectonics)
Rhyolitic (high viscosity)
What characteristics are shown by AA lava? (Major extrusive tectonics)
- heat loss = high viscosity
- forms a crust
- fast moving
What characteristics are shown by Pahoehoe lava? (Major extrusive tectonics)
- slow moving
* well developed skin forms
What two types of eruptions can occur? (Major extrusive tectonics)
- Fissure eruptions
* Vent eruptions
What is the silica content of basaltic lava? (Major extrusive tectonics)
Low
Name the 6 types of volcanoes (major extrusive tectonics)
- ash/cinder
- basic shield
- caldera
- composite cone
- fissure
- acid dome
What does an ash/cinder cone volcano look like? (Major extrusive tectonics)
- no lava
- small
- made of loose grainy cinders
- steep sides
- small crater
What is an example of an ash/cinder cone volcano? (Major extrusive tectonics)
Particutin, Mexico
What does a basic shield volcano look like? (Major extrusive tectonics)
- basaltic lava
- very large
- low slopes
- large crater
What is an example of a basic shield volcano? (Major extrusive tectonics)
Islands of Hawaii
What does a caldera volcano look like? (Major extrusive tectonics)
- rhyolitic lava
- circular depressions found on the summit
- form by collapsed of the volcano itself
- edges appear as a steep cliff
What is an example of a caldera volcano? (Major extrusive tectonics)
Vaues, New Mexico
What does a composite cone look like? (Major extrusive tectonics)
- andesitic lava
- very large
- steep sides
- small crater
What is an example of a composite cone volcano? (Major extrusive tectonics)
Mount St Helens, USA
What does a fissure volcano look like? (Major extrusive tectonics)
- basaltic lava
- no central crater
- crack in the ground
- vast quantities of lava
What is an example of a fissure volcano? (Major extrusive tectonics)
Los Pilas, Nicaragua
What does an acid done volcano look like? (Major extrusive tectonics)
- rhyolitic lava
- dome grows from within
- dome cools, hardens, then shatters
What is an example of an acid dome volcano? (Major extrusive tectonics)
Novarupta, Alaska
Why do explosive eruptions occur? (Major extrusive tectonics)
Cooler magma reaches the surface and dissolved gasses can’t escape, so pressure builds
What are the 7 types of explosions from a volcano? (Major extrusive tectonics)
- Icelandic
- Hawaiian
- Strombolian
- Vulcanian
- vesuvian
- Peléean
- Plinian
What type of lava flows from a Icelandic eruption? (Major extrusive tectonics)
Basaltic
What type of lava flows from a Hawaiian eruption? (Major extrusive tectonics)
Basaltic
What type of lava flows from a Strombolian eruption? (Major extrusive tectonics)
Basaltic (thicker)
What type of lava flows from a Vulcanian eruption? (Major extrusive tectonics)
Basaltic, andesitic and rhyolitic
What type of lava flows from a Vesuvian eruption? (Major extrusive tectonics)
Basaltic, andesitic and rhyolitic
What type of lava flows from a Peléean eruption? (Major extrusive tectonics)
Andesitic and rhyolitic
What type of lava flows from a Plinian eruption? (Major extrusive tectonics)
Rhyolitic
What happens when a Icelandic volcano erupts? (Major extrusive tectonics)
Lava flows gently from fissures
What happens when a Hawaiian volcano erupts? (Major extrusive tectonics)
Lava flows gently from central vent
What happens when a Strombolian volcano erupts? (Major extrusive tectonics)
Frequent, explosive eruptions of tephra and steam
What happens when a Vulcanian volcano erupts? (Major extrusive tectonics)
Few but violent eruptions that contain ash and gas
What happens when a Vesuvian volcano erupts? (Major extrusive tectonics)
After long periods on inactivity, very violent gas blasts high into the sky
What happens when a Peléean volcano erupts? (Major extrusive tectonics)
Very violent eruptions and huge pyroclastic flows
What happens when a Plinian volcano erupts? (Major extrusive tectonics)
Exceptionally violent with gas and ash, torrential rain storms
