Chapter 8 Flashcards
Which of the following geological conditions is required for the formation of geysers?
intense heat
What is a caldera?
a large, bowl-shaped depression that forms at the top of some volcanoes
What type of volcano is NOT found on a plate boundary?
hot spot
What kind of magmas produce violent volcanic eruptions?
those rich in silica
Centeral Vent
The one main vent going through the middle of a volcano.
Which statement is accurate about volcanic eruptions?
a. The lower the viscosity magma, the more explosive the eruption.
b. The lower the amount of dissolved gas, the more explosive the eruption.
c. There is no relationship between viscosity and type of eruption.
d.The higher the viscosity of magma, the more explosive the eruption.
The higher the viscosity of magma, the more explosive the eruption.
What type of lava is likely to form a lava dome when it erupts from the earth?
thick, slow moivng lava
What is the molten rock inside Earth called?
magma
What is the name of the opening through which lava flows?
Vent
A’a, Pahoehoe, and Pillow are types of what?
low vicosity lava
Which of the following is true of supervolcanoes?
a. they may have contributed to mass extinctions.
b. they are classified as sheild volcanoes
c. they incluce mount pintaubo in the phillipines
d. they have frequent, explosive eruptions.
They may have contributed to mass extinctions.
How often does Old Faithful in Yellowstone National Park erupt?
once a hour
What landform is created when a large amount of less viscous lava flows over a large area?
plateaus
Which term describes a volcano that has had no activity for quite a long time?
extinct
The first step in the formation of a volcano is rock melting in the ______.
mantle chamber
A region within Earth surrounded by solid rock and containing magma.
What do satellites sense in order to see if a volcano will soon erupt?
temperature and deformation
What is tephra?
erupted solid particles by a volcano
What can disrupt flights and cause cooler temperatures by blocking the Sun?
volcanic ash
Which is true of the oldest volcanoes in a hotspot chain?
they are furthest from the hotspot
Approximately how many geysers exist worldwide?
1,000
type of volcano has a broad base and steep sides?
composite
A volcano with a broad base, steep sides, and often a crater at the top. The volcano is composed of alternating layers of ash and lava flows. Also called a stratovolcano.
Where are most of the world’s volcanoes found?
around the pacific ocean in the ring of fire
How many hot spots exist on Earth?
50
a sign that an eruption could soon occur?
ground swelling along the slope of the volcano
example of a cinder cone volcano?
mount paricutin
