1. Volcano Stations Answers

2. Station 1
A volcano is a place where magma reaches the surface due to its lower density
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.

3. Station 1continued
3. The types of forces involved are both 4. 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)

5. Station 2 continued High Water Content High Silica Content
6. High water and silica content can make magma explosive
High Water Content
High Silica 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.
Silica-rich magma is stiff
It hardens at the vents clogging them
Pressure increases at the vent trapping gas until it explodes

6. Station 2 continued 7.
(also called cinders)

7. 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

8. Section 3
9. Non-explosive volcanoes have lava flows that are relatively calm
examples include Hawaii and Mid-Atlantic Ridge Volcanoes

9. Section 3 continued High Viscosity/Slow Flowing Lava
Low Viscosity/Fast Lava Flow
10.
11.

10. 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

11. Section 4 Shield Volcano 12.
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)

12. Section 4 continued Cinder Cone Volcano 13.
Moderately explosive pyroclastic material but it is not cemented together (erodes quickly)
Small but steep slopes
Example: Mexico’s Paricutin volcano

13. Section 4 continued Composite Volcano 14.
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

14. 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

15. 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

16. 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