Question

question 9 (5 points) listen which of the following factors causes an explosive eruption from a composite volcano? a) water accumulated in the vent b) large buildup of pressure from gases c) mantle plumes d) pyroclastic flows

Explanation:

Composite volcanoes have explosive eruptions mainly due to the large buildup of pressure from gases within the magma. As gases like water - vapor, sulfur dioxide etc. dissolve in the magma under high pressure and then expand rapidly when the pressure is released (such as when the magma rises towards the surface), it causes an explosive eruption. Water accumulated in the vent is not the main cause. Mantle plumes are more associated with hot - spot volcanism. Pyroclastic flows are a result of explosive eruptions, not a cause.

Answer:

B. Large buildup of pressure from gases