Ch.3: Volcanoes and the Rock Cycle

Lesson 3:The causes and prediction of

Volcanic Eruptions

Active/Dormant Volcanoes

Hot Spots

Question #1

• Pressure• Non-explosive (shield or cinder-cones)• (Magma comes from the upper mantle,

which has a low to medium viscosity and low to medium gas.)

Question #2

• Temperature• Non-explosive (shield or cinder-cone)• (Magma comes from deeper in the mantle

and tends to have low viscosity.)

Question #3

• Water• Melting point• (Subducting crust is oceanic, and so the

rock is well hydrated with water, which is released as vapor during subduction.)

Question #4

• Explosive (composite or cinder-cone)• 80%

Question #5

• Pacific • Ring of Fire• (Most coastlines along the Pacific are

within subduction zones except for California.)

The Ring of Fire

Hot Spots

Question #6

• 15 % (most located in Iceland and Eastern Africa).

• 5 % (most form islands such as Hawaii, Easter isles, Galapogos, Canary, Tahiti, etc.)– Note: a single hot spot can form multiple

islands as the plate moves over it. – Bill Nye volcano (3:28)

Question #7

• Extinct• Active• Dormant (sleeping)

Question #8

• Earthquakes• Frequency and intensity

Question #9

• Volcanic gases• Sulfur dioxide (SO2) to Carbon dioxide

(CO2).• Increase

Question #10

• Swell or bulge.• Tiltmeter• Tiltmeters bounce laser beams off

reflectors positioned on the mountain that can measure a few milimeters of ground movement.

Question #11

• Infrared • temperature

Infrared Satellite image