Earth Science - Volcanoes - Quiz 11

dormant

If a volcano has not had any eruptions in historic times, but seismographs still reveal that they are still capable of an eruption, it would be considered ___________.

basaltic shield volcanoes

Kilauea and Mauna Loa (in Hawaii) are ________.

a stratovolcano

Mount St. Helens is ________.

andesite

The average composition of rocks comprising a large composite cone or stratovolcano is similar to __________.

True

The viscosities of magmas increase with increasing percentages of silica.

all of these

Which of the following factors help determine whether a volcanic eruption will be violent or relatively quiet?

rhyolite, andesite, basalt

Which one of the following shows the correct order (left to right) of decreasing magma viscosity? (more viscous to less viscous)

High viscosity and dissolved gas

________ tend to increase the explosive potential of a magma body beneath a volcano.

composite/stratovolcanoes

___________ are large, fairly steep-sided volcanoes composed of lavas and pyroclastic layers.

shield volcanoes

___________ are massive, gently sloping volcanoes built of successive, basaltic lava flows.