Descending into Earth's interior, temperature and pressure on rock _____________________.
What is increase?
100
four gases that commonly escape from volcanoes...
What is carbon dioxide, water vapor, nitrogen, and sulfur?
100
Rhyolitic lava flows are very viscous because the have a high ___________ content.
What is silica?
100
This forms when rock, that was once magma in a pipe, is resistant to erosion and remains standing above the surface after the rest of the volcano has worn away.
What is a volcanic neck?
100
Volcanoes with _______-viscosity magmas erupt the most explosively.
What is high?
200
Where slabs of oceanic lithosphere are subducted under continental lithosphere, a __________________ volcanic arc can form.
What is continental?
200
The accumulation of fluid basaltic lava produces this type of volcano.
What is shield?
200
This kind of lava flow resembles the twisted braids in a rope as it cools and hardens.
What is PaHoeHoe?
200
another name for a composite cone volcano
What is stratovolcano?
200
Why do high-viscosity magmas cause the most explosive volcanoes?
What is because thicker, slower-moving magmas trap the gases in pockets that increase in size and then explode violently.
300
Where slabs of oceanic lithosphere are subjected under another oceanic plate, a ___________ can form.
What is an ocean trench?
300
The most explosive volcanic eruptions come from this type of volcano.
What is composite cone?
300
If a lava flow is very viscous, it can be described as _______ and _______.
What is thick and slow?
300
These form where magma flows between parallel layers of sedimentary rock.
What is sills?
300
Volcanoes that contain magma with these 3 characteristics will erupt quietly with a fluid lava that flows rather than explodes.
What is low silica content, low gas content, and low-viscosity.
400
Intraplate volcanism, as occurs on the Hawaiian Islands, is cause by a rising ________ ________.
What is mantle plume?
400
saturated volcanic debris that rapidly moves down steep, volcanic slopes as a mudflow
What is a lahar?
400
The higher the temperature of lava, the __________ viscous it is.
What is less?
400
These form from plutons deep beneath the Earth's surface as they clump together forming a huge irregular mass that cools slowly underground forming granitic rock.
What is batholiths?
400
Volcanoes that contain magma with these 3 characteristics will explode violently.
What is high silica content, high gas content, high-viscosity.
500
When two continental plates diverge, volcanoes can be formed within the _________ ___________ that iscreated by the divergence.
What is rift valley?
500
The magma that feeds most volcanoes moves from a magma chamber toward the surface through these.
What is pipes?
500
If a lava flow is less viscous, it can be described as ______ and _______.
What is thin and runny?
500
This is a pluton that has pushed the overlying rock layers upward and because it was formed from magma with high viscosity, it bulges upward instead of spreading out into an even layer.
What is a laccolith?
500
Pyroclastic flows composed of hot gas, glowing ash, and large rock fragments that blast out of volcanoes are usually NOT associated with this type of volcano.