What tectonic environment is NOT associated with volcanic activity?
- transform fault boundaries
In Canada, volcanoes are found in the following techtonic environment, except:
- transform fault boundaries
Where are Canadian volcanoes located?
- British Columbia, Yukon
The country of ____ is a volcanic plateau built of basaltic lava erupted from a hot spot underlying the Mid-Atlantic Ridge in the North Atlantic Ocean.
- Iceland
Place the following volcanic hazards in order of their deadlines, with the most deadly process at the top and the least deadly process at the bottom.
1) pyroclastic flows
2) tsunami
3) lahars
4) gas
5) lava flows
A _____ is a mudflow composed of volcanic debris that is fluid when moving, but solidifies soon after stopping.
- lahar
A scientist determines that ‘crystal volcano’ is 5,000 years old. What can the scientist assume about the ages of three other nearby volcanoes?
- if the volcanoes were created by a hot spot, the ages of the other volcanoes depend not he order of crystal volcano in the sequence
- if the volcanoes were created by subduction, they are likely to be about the same age
If there was a large volcanic eruption in the cascade range, which flight could be affected by volcanic ash?
- Edmonton to Vancouver
Some phenomena that may be used to predict volcanic eruptions include ____.
- seismic waves
- ground deformation
- gas emissions
Which gas was ultimately responsible for the deaths of thousands of villagers near Lake Nyos, Cameroon, in 1986?
- carbon dioxide
Lava flows are rarely responsible for many volcano related deaths because they ____.
- move too slowly
A pyroclastic flow _____.
- can move at speeds that exceed 100 m/sec.
- is a mixture of magma, volcanic ash and gas, and air
- can reach temperatures of 350 celsius
How did the population of Heimaey, Iceland, take advantage of the lava flows that nearly destroyed their harbour?
- installed pipes to pump water through the slowly cooling lava, creating their own thermal heating system
How do hot spots and tectonic plates move relative to each other?
- hot spots are static relative to tectonic plates
Long, linear ____ eruptions composed of low-viscosity, low-volatile lava flows are typical in the country of Iceland.
- fissure
Place the vents of the eruptive sequence of the 1980 Mount St. Helens in order of their occurrence, with the oldest event at the top and the most recent event at the bottom.
1) rising magma begins to reshape Mount St. Helens, setting off a series of earthquakes
2) the volcanic bulge on Mount St. Helens collapses, generating an avalanche
3) a drop in pressure on the side of Mount St. Helen’s creates a pyroclastic flow
4) rapid escape of volcanic gases blew magma upward, generating a psi naan eruption phase on Mount St. Helens
Which of these hazards, associated with Mount Baker, could affect Vancouver?
- Lahar
- large quantity of volcanic ash
What happens to rising magma in subduction zones?
- the magma becomes enriched in silica (SiO2)
- the magma melts the overlying crust
Subduction zones volcanoes affect humans more than any other type of volcanic activity because ____.
- the areas around subduction zone volcanoes are often heavily population
- they eject material directly into the atmosphere, causing short-term changes in climate
Undersea volcanic eruptions are one culprit int he formation of ____, which are the second most deadly volcanic process.
- tsunami
What is the dominant deformation force that created a large crack on the seafloor?
- tension
The potential hazards of volcanic eruptions are extensive and include
- tsunamis
- lahars
- lava flows
- poison gas
Which of the following is a primary volcanic hazard related to the interaction between lava and ice?
- Jokulhlaup
One of the most dangerous phases of a volcanic eruption occurs when ____.
- less energy is fed into the eruption column, causing it to collapse and sending pyroclastic flows down the flanks of the volcano.
