3/22/24, 10:06 PM
Geology Flashcards | Quizlet
https://quizlet.com/32357452/geology-flash-cards/
4/8
During the 1990s, hundreds of trees were
killed at Mammoth mountain, California, by
the diffuse emission of _______ gas.
CO2
Several geologic phenomena are being
studied as signs of an impending volcanic
eruption. These include seismic waves,
___________ , and the release of gases.
grounded information
On may 8, 1902 a massive eruption of this
volcano killed 30,000 people In the town of
St. Pierre. The volcano was
Mont pelee, Martinique
In 1883, Edvard Munch created his famous
painting the scream after witnessing a blood
a red sky over Oslo, Norway, caused by the
eruption of
Krakatau volcano, Indonesia
The two most active Cascade Range
volcanoes over the past 4000 years are
Mount St. Helens and Mount Shasta
Active volcanoes today in Oregon and
Washington, including Mount St. Helens,
result from
the subduction of the Juan de Fuca plate beneath North America
A Scoria cone is likely to form if lava is low in
gas content and high in viscosity
False
The highest temperatures and highest SiO2
contents are in basaltic magma, giving it the
lowest viscosity
False
over 90 percent of volcanism is associated
with the edges of tectonic plates, and most
of the rest is caused by hot spots.
True
About 80 percent of the magma reaching
the earths surface is basaltic, with only about
10 percent andesitic and 10 percent rhyolitic.
True
The process of mineral formation in a
cooling magma is called crystallization
True
At oceanic spreading centers, magmas are
rhyolitic in composition
False
Because vulcanologists are aware of the
potential hazards, no vulcanologists has ever
been killed studying a volcano.
False
Although there are 92 naturally occurring
elements, a mere eight make up more than
98 percent of the Earths crust.
True
No magmas contain dissolved gasses
False
Basaltic magmas have low contents of SiO2,
low temperature, low viscosity, and allow
easy escape of gasses, producing peaceful
eruptions
False
When magma nears the surface, gases come
out of solution and help cause volcanic
eruption.
True
Geology
