GEOL- Ch4.2 Volcanoes Quiz

Shield volcanoes have low slopes primarily because

• the layers flatten out due to tectonic forces.

• their abundant ash layers spread out large distances.

• they never erupt from the same place twice.

• the low viscosity of basaltic magma allows it to flow downhill for long distances.

The collapse of crustal rock above a magma chamber following the emptying of that large magma chamber can result in the formation of?

• The formation of a volcano's summit on a stratovolcano.

• The formation of a volcanic dome.

• none of the above

• The formation of a volcanic caldera.

What is the difference between a lahar and pyroclastic flow?

• Lahars are only associated with stratovolcanoes and volcanic domes while pyroclastic flows are associated with shield volcanoes and cinder cones.

• Lahars involves very hot gasses and pyroclastic debris, while pyroclastic flows involve very hot water and pyroclastic debris, both flow down the flanks of the volcano.

• Lahars are only associated with shield volcanoes and cinder cones while pyroclastic flows are associated with stratovolcanoes and volcanic domes.

• Lahars involves water and pyroclastic debris, while pyroclastic flows involve very hot gasses and pyroclastic debris, both flow down the flanks of the volcano.

What are common volcanic features associated with mid-ocean ridges? choose all that apply

• flood basalts

• all of the choices

• deep-sea hydrothermal vents

• cinder cone volcanoes

• lava flows on the ocean floor, forming pillow basalts

Where does most volcanism occur on Earth?

• Along transform boundaries where eruptions can occur and lava flows or explosive eruptions.

• Along mid-ocean ridges where eruptions are slow, gentle, and oozing.

• Subduction zone Convergent boundaries where eruptions are explosive, fast, and damaging.

Which is NOT commonly associated with lava domes, stratovolcanoes, and calderas?

• viscous to very viscous lava

• dangerous volcanic hazards

• explosive eruptions

• mafic-intermediate lava compositions

Which of the following does NOT precede a volcanic eruption?

• All of these choices are correct

• changes in land surface orientation and elevation

• increase in earthquake/seismic activity

• increased gas emissions from a volcano

• formation of pyroclastic flow

Which setting does NOT produce the more dangerous types of volcanoes or volcanic features?

• Continental rifts

• Subduction zones

• Continental hotspots

• Continental Collisions

Which volcanic type is rare and has not been observed in modern times, and produce some of the largest and lowest viscosity types of eruptions?

• Supervolcanoes

• Stratovolcanoes

• Cinder cones

• Flood Basalts

Which is the correct description about the hazards of lava flows?

• Where lava flows, it will change the landscape and makes areas uninhabitable, but often times there is enough warning to evacuate the area in its path.

• They produce fine ash that blanket the ground and can impact regions far away.

• They only affect the area near the central vent of a volcano.

• Lava flows start at the central vent and flow so fast down the steep slopes of stratovolcanoes that cars cannot escape if in its path.