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 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 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 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

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 High Viscosity/Slow Flowing Lava Low Viscosity/Fast Lava Flow 10. 11.

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 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)

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

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

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