Download Volcano Stations Answers

VOLCANO STATIONS
ANSWERS
Station 1
1.
A volcano is a place where magma reaches the surface due to its lower density
2.
A volcano is a “window” into the earth’s interior
They allow us to study material that comes
from deep within the crust and possibly from
parts of the mantle.
Station 1continued
3. The types of forces involved are both
constructive and destructive
4.
Station 2
5. Explosive volcanoes violently blows up. Examples include volcanoes along the ring of
fire and take place at subduction zones
Mt. Redoubt, Alaska (1990)
Mt. St. Helens (1980)
Pinatubo (1991)
Station 2 continued
6. High water and silica content can make magma explosive
High Water Content
◦ water deep within the earth is under a lot
of pressure so it stays dissolved in magma
◦ When the magma move up quickly,
pressure decreases and the water turns to
gas
◦ As pressure decreases, the gas expands
and explodes
◦ Explosive volcanoes occur along
subduction zones where ocean water
also becomes subducted with the plate.
High Silica Content
◦ Silica-rich magma is stiff
◦ It hardens at the vents clogging them
◦ Pressure increases at the vent trapping
gas until it explodes
Station 2 continued
7.
(also called cinders)
Section 2 continued
8. Pyroclastic flows are dangerous
because they can travel at over
200 km/hr and temperatures can be
greater than 700 degrees Celsius! They
also give off Poisonous gas
Section 3
9. Non-explosive volcanoes have lava flows that are relatively calm
◦ examples include Hawaii and Mid-Atlantic Ridge Volcanoes
Section 3 continued
10.
High Viscosity/Slow Flowing Lava
11.
Low Viscosity/Fast Lava Flow
Identify the volcanoes pictured below as either explosive or
nonexplosive?
(B) Kilauea eruption
NON-EXPLOSIVE
(D) Mayon Volcano, Philippines
(A) Aleutian Island Volcano
EXPLOSIVE
EXPLOSIVE
(C) Eruption along
midocean ridge
NON-EXPLOSIVE
Section 4
12. Shield Volcano
◦ Layers of lava form repeated non-explosive
eruptions build up
◦ Lava is runny creating a volcano with gently
sloping sides
◦ Hawaii’s Mauna Kea volcano is the tallest
mountain on earth if you measure it from the
sea floor to the top (taller than Everest)
Section 4 continued
13. Cinder Cone Volcano
◦ Moderately explosive pyroclastic material but it
is not cemented together (erodes quickly)
◦ Small but steep slopes
◦ Example: Mexico’s Paricutin volcano
Section 4 continued
14. Composite Volcano
◦ Also known as Stratovolcanoes
◦ Most common type
◦ Alternate explosive eruption followed by quiet
lava flows
◦ The combination of both types of eruptions
produce layers of pyroclastic material and lava
◦ Broad base and steep at the top
◦ Example: Japan’s Mount Fugi
Identify the pictures below as one of the THREE types of
volcanoes.
(A) Mount Fuji, Japan
– STRATOVOLCANO
(B) Sunset Crater, Arizona –
CINDER CONE
(C) Iceland volcano – SHIELD VOLCANO
Section 5
15. As pressure increases, higher temperatures
are needed to melt the rock
16. Pressure from the weight of the rock above
the mantle squeeze the rocks; molecules can’t
move around so the rocks cannot melt
17. Temperature generally stays the same at the
top of the mantle but as the pressure decreases,
the rocks can melt and become magma
Section 6
18.
◦ There is a large scale eruption
◦ Volcanic ash and sulfur-rich gases spread through the atmosphere
◦ Less sunlight reaches the earth
◦ The average global temperature drops
◦ The earth experiences longer, harsher, winters and wetter, milder summers
◦ Worldwide food shortages occur because of widespread crop failures
19. The nickname associated with the 1815 eruption of Tambora was “The Year Without a
Summer”. It was so named because volcanic ash and gases blocked out the sun and it
was much colder
20. Ash from Mount Pinatubo blocked out the sun in the Philippines and changed the
global temperature by 0.5 degrees Celcius