Starr-Aisa Hayes
Intro to Physical Geology
1.
Why block lavas are likely to create short, prominent flows rather than long, fluid
flows?
Block lavas are likely to create short, prominent flows rather than long, fluid flows because
block lavas have a higher silica content and are more viscous.
2.
Assume you live near Mt.St. Helens and the volcano are going through an explosive
eruption. Explain the effect pyroclastic materials would have on your home.
The effect pyroclastic material would have on your home is that ash
can collect in thick deposits
(possibly collapsing the roof), can mix with heavy rain to create lahars, or can potentially be part
of a pyroclastic flow.
3.
Along which tectonic boundary would the greatest amount of magma be generated
every year? Explain why.
The convergent boundaries would be where the greatest amount of magma would be generated
every year because magma produced by dehydration of plate water and partial melting.
4.
Differentiate the three types of magma based on their igneous compositions,
temperatures, and silica contents.
The three types of magma are basaltic, andesitic, and rhyolitic.basaltic magmas have a low Silica
content (45-55%) and are referred to as mafic in composition, they have a temperature of
1000 to
1200
℃
.
Rhyolitic magma contains more than 65% of Silica and is referred to as felsic and has a
temperature of
650 to 800
. Then
℃
andesitic magma is intermediate in composition (55-65%
silica) and then the temperature of
800 to 1000
℃
5.
How do scientists use earthquakes to determine if a volcano may erupt soon?
Scientists use seismographs that record each earthquake's length and strength
to determine if an
eruption is imminent to determine if a volcano may erupt soon.
