Volcanoes
Which of the following is a sign of an impending volcanic eruption?
-change in gas emission -ground deformation -earthquakes
_______ magma contains about 70% silica.
Felsic
Which kind of igneous rocks have large grains?
Intrusive
which of the following planets DO NOT have active volcanoes?
Jupiter
Which is the largest volcano on Earth?
Mauna Loa
Which of the following is not a composite volcano?
Mauna Loa
which of the following volcanoes is located in Japan?
Mt. Fuji
Most of the world's active volcanoes are located in the ________ which circles the Pacific Ocean.
Ring of Fire
Which of the following volcanoes erupted in 79 A.D. and buried Pompeii?
Vesuvius
largest pluton, irregular shape
batholith
Small volcanoes on the seafloor are sometimes called
black smokers
When the top of a volcano collapses, it creates a larger depression around the vent called a ________.
caldera
Paricutin in Mexico is a
cinde cone
material is ejected high into the air and falls back around the vent
cinder cone
smallest volcano
cinder cone
steepest slope, concave sides
cinder cone
usually formed by a single eruption
cinder cone
Mount St. Helens is a
composite
Mt. Vesuvius is a...
composite
alternating lava flows and tephra, sometimes explosive sometimes not
composite
can be violently explosive
composite
can produce pyroclastic flows or mudslides
composite
felsic lava, most viscous lava
composite
most dangerous volcanoes
composite
occur at convergent boundaries (Ring of Fire)
composite
Most volcanoes occur at _____ boundaries
convergent
The bowl shaped depression around the volcano's vent is the _____.
crater
pluton that cuts across preexisting rock, often start in a rock crack
dike
Mid-ocean ridges are volcanic landforms that form at ________ plate boundaries
divergent
Which kind of igneous rocks are usually light in color?
felsic
What do tilitmeters measure?
ground deformation
The most explosive volcanoes have magma that has a _____ silica content, a ____ viscosity, and a _____ gas content.
high high high
______ are unusually hot regions of the mantle which melts rock and forces it through the crust to form a volcano.
hot spots
mushrrom-shaped pluton
laccolith
What is a large outpouring of lava from long narrow openings in the crust which builds layers of lava?
lava plateau
Magma rises because it is ______ than the surrounding rock.
less dense.
Felsic magma is ____ explosive than mafic magma.
more
forms when outside of a volcano erodes and solidified pipe is left standing
neck
connects a magma chamber of the vent
pipe
Lava _______ form when lava flows out of fissures (or cracks) in the earth.
plateaus
intrusive igneous rock body
pluton
A ___________ happens when gas, ash, and tephra move down the slop of the volcano.
pyroclastic flow
Hawaiian Islands are
shield
Iceland was formed by
shield
contain a low percentage of gas and silica
shield
largest volcano
shield
mafic lava, least viscous lava
shield
most formed from hotspots in Earth's mantle
shield
non-explosive eruptions
shield
straight gentle slope
shield
The more _____ magma contains, the most viscous it is.
silica
pluton that is parallel to the rocks it intrudes
sill
similar to a batholith, but smaller
stock
The peak (or highest point) of a mountain is also called the ______
summit
______ is dust, ash, rock fragments, volcanic blocks, or volcanic bombs thrown into the air during an eruption
tephra
An opening in the Earth's crust where lava escapes is the _____.
vent
Lava erupts through the opening in the EArth's crust called a ______.
vent
_____ is a liquid's resistance to flow.
viscosity
A _______ is formed when the solidified volcanic pipe remains after most of the outside of the volcano has been eroded away.
volcanic neck
the most abundant gas released during a volcanic eruption is ______. the second is ________.
water vapor carbon dioxide