Science Olympiad Dynamic Planet Practice Test

What type of volcano is formed by slow eruptions of highly viscous lava?

1. Stratovolcanoes

2. Cinder cones

3. Lava domes

4. Super volcanoes

The correct answer is: Lava domes

Lava domes are formed through the slow eruptions of highly viscous lava, which is thick and sticky. This type of lava tends to pile up near the vent, creating a dome-shaped formation rather than flowing away like less viscous lava would. The high viscosity means that the lava does not travel far, resulting in steep sides that characterize a lava dome. This formation contrasts with other types of volcanoes. For example, stratovolcanoes are typically associated with explosive eruptions as well as flows of both viscous and less viscous lava, but their overall eruption style includes more violent activity. Cinder cones are formed from smaller eruptions that produce loose volcanic debris, while super volcanoes are characterized by massive eruptions that can lead to caldera formation, typically involving large volumes of material at once. Each type has distinct characteristics and eruption styles, which is why lava domes specifically are tied to the slow and viscous nature of their lava flows.