Sept 23 lecture (volcanoes continued)

Question 1

caldera=

Answer 1

a large volcanic crater, usually formed by a major eruption (causes mouth of volcano to collapse)

Question 2

where do the following products of volcanoes go?

• hydrogen
• nitrogen
• CO2
• water
• SO2

Answer 2

• hydrogen escapes to space
• nitrogen, CO2, SO2= to atmosphere
• water: to oceans

Question 3

nuclear winter hypothesis

Answer 3

dust from volcano can block sunlight, decrease global temp

- can take years to settle

Question 4

how does sulfuric acid mist from volcanoes decrease mean monthly temp locally?

Answer 4

droplets reflect sunlight

- suggest: spray it to reverse global warming. would be temporary and have negative effects

Question 5

what would happen if volcanism stopped altogether?

Answer 5

no longer emit CO2: rock weathering would remove CO2 from the atmosphere and the earth would slowly freeze solid

Question 6

define the 3 classifications of volcanoes

Answer 6

• active= erupted in recent history
• dormant= no historic eruptions but not badly eroded
• extinct= no historic eruptions and badly eroded

Question 7

volcanic precursors to monitor: (5)

Answer 7

• seismic activity (rising magma/ gas produce small eq)
• steam forming/ temp changes
• bulging, tilting, or uplifting= rising magma
• monitor gas emissions around volcano
• animal behavior

Question 8

volcanoes differ in their patterns of activity, but statistically:

• typical volcano erupts avg every __yrs
• 30% erupt every ___ yrs
• 2% erupt every ___ years

Answer 8

220
1000
10000