Volcano Stations Answers - PowerPoint Presentation

Slide1

Volcano Stations Answers

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 interiorThey 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 4.

constructive and destructive

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

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 gasAs pressure decreases, the gas expands and explodesExplosive 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

6. High water and silica content can make magma explosive

(also called cinders)

Station 2 continued

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

Section 3

9. Non-explosive volcanoes have lava flows that are relatively calm

examples include Hawaii and Mid-Atlantic Ridge Volcanoes

Section 3 continued

High Viscosity/Slow Flowing Lava

Low Viscosity/Fast Lava Flow

10.

11.

Identify the volcanoes pictured below as either explosive or nonexplosive?

(A) Aleutian Island Volcano

(D)

Mayon

Volcano, Philippines

(B) Kilauea eruption

(C) Eruption along midocean ridge

EXPLOSIVE

NON-EXPLOSIVE

NON-EXPLOSIVE

EXPLOSIVE

Section 4

Shield Volcano

Layers of lava form repeated non-explosive eruptions build up

Lava is runny creating a volcano with gently sloping sidesHawaii’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

Moderately explosive pyroclastic material but it is not cemented together (erodes quickly)

Small but steep slopesExample: Mexico’s Paricutin volcano

13.

Section 4 continued

Composite Volcano

Also known as Stratovolcanoes

Most common typeAlternate explosive eruption followed by quiet lava flowsThe combination of both types of eruptions produce layers of pyroclastic material and lavaBroad base and steep at the topExample: Japan’s Mount Fugi

14.

Identify the pictures below as one of the THREE types of volcanoes.

(A) Mount Fuji, Japan – STRATOVOLCANO

(C) Iceland volcano – SHIELD VOLCANO

(B) Sunset Crater, Arizona – CINDER CONE

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 atmosphereLess sunlight reaches the earthThe average global temperature dropsThe earth experiences longer, harsher, winters and wetter, milder summersWorldwide food shortages occur because of widespread crop failures19. 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