Before lava reaches the surface, the molten material is called ________________
magma
100
Volcanic belts form along ___________________
the boundaries of Earth's plates
100
Hardened magma in a volcano’s pipe that remains when softer rock around it has worn away is called a(n) _________________________.
volcanic neck
100
When groundwater heated by magma rises to the surface and collects in a natural pool, it is called a _______________.
hot spring
100
In volcanic areas, groundwater heated by magma is a source of ________________ energy.
geothermal energy
200
The viscosity of magma depends upon its silica content and its ___________________
temperature
200
A(n) ____________________ is an area where material from deep within the mantle rises and then melts, forming magma.
hot spot
200
An eruption of ash, cinders, bombs, and gases from a volcano is called a(n) _________________________.
pyroclastic flow
200
What is the landform that forms when a mass of hardened magma is uplifted, causing the layers of rock to bend upward?
dome mountain
200
The main hazard from a quiet volcanic eruption is (a) volcanic gases (b) lava flows (c) geysers (d) pyroclastic flows
(b) lava flows
300
Pahoehoe is (a) cooler, slower-moving lava (b) fast-moving, hot lava (c) volcanic ash (d) lava with a rough, chunky surface
(b) fast-moving, hot lava
300
The bowl-shaped area around a volcano’s central vent is called a(n) ____________________.
crater
300
Groundwater heated by a nearby body of magma can spray from the ground under pressure, forming a(n) ____________________.
geyser
300
The volcanoes along converging oceanic plate boundaries may form
an island arc
300
A quiet eruption may produce slow moving, cooler lava that hardens to form rough chunks. This type of lava is called ____________________.
aa
400
The major ingredient of magma is ______________.
silica
400
Forms when lava flows alternate with explosive eruptiosn of ash, cinder and bombs
composite volcano
400
Describe a dormant volcano
A dormant, or sleeping, volcano is like may not erupt for thousands of years. However, the volcano’s body of magma may heat nearby groundwater, creating hot springs or geysers.
400
A mass of rock formed when a large boyd of magma cools inside the crust is called a
batholith
400
The resistance of a liquid to flowing is called ____________________.
viscosity
500
The smallest lava fragments produced by an explosive eruption are called volcanic ____________________.
ash
500
Forms when repeated lava flows build up a broad, gently sloping mountain.
shield volcano
500
Describe an active volcano.
An active, or live, volcano is one that is erupting or has shown signs that it may erupt in teh newar future.
500
If the magma chamber beneath a volcano empties and then collapses, what kind of feature will form? .
caldera
500
Forms when cinders erupt again and again, piling up around the vent to form a steep, cone-shaped hill.