Exam 5: Volcanoes and Volcanic Hazards

How does decompression melting generate magma at rift zones?

A ________ is a submarine volcano.

What kind(s)of lava are most closely associated with composite cones?

Pahoehoe and Aa can form in the same lava as it flows away from the eruptive vent.How does each form? What role does temperature play?

Provide three examples of how lahars can form.

Why are block lavas, such as an andesite lava, likely to create short, prominent flows rather than long, fluid flows?

________ are small vents that emit volcanic gases.

In order to cover such large expanses of seafloor, shield volcanoes erupt ________ lava.

Carefully study the eruption visible in this figure, paying close attention to the appearance of the rocks produced when the lava solidifies and the pyroclastic materials fall to earth.Based on your analysis, would you say that the volcano has more layers of solidified lava or more layers of pyroclastic deposits? What does your answer mean for the kind of eruption style: quiescent or explosive?

The more the silica in magma, the lower the viscosity.

How do lava tubes form in basaltic lavas? How can the exterior solidify if the interior is still fluid?

Which of the following eruptive materials can be described as basaltic, vesicular ejecta found around cinder cone volcanoes?

Explain how sulfur dioxide gas erupted from a volcano can affect global climate.

What is the name of the small holes created by gas bubbles on the surface of scoria?

Which of the following changes are not evidence of migrating magma?

Volcanic island arcs and continental volcanic arcs are both associated with convergent plate boundaries.However, the lavas that their volcanoes erupt are different.Where does the lava come from for each type of volcanic arc?

What is the driving force behind pyroclastic flows?

Define magma.

Based on the volcanic type and construction of the flanks, what assumptions can you make about the type of lava?

Which volcanic type(s)can have pyroclastic ejections during eruptions?