Science Olympiad Dynamic Planet Practice Test

Which volcano type can produce violent eruptions but generally does not allow lava to flow far from the vent?

1. Stratovolcanoes

2. Cryptodomes

3. Cinder cones

4. Shield volcanoes

The correct answer is: Cryptodomes

The correct response is based on the characteristics of cryptodomes. These formations arise when lava is very viscous, preventing it from flowing away from the vent and causing the lava to build up in place. This build-up can lead to the formation of a dome structure over time. Cryptodomes can produce violent eruptions due to the pressure that can build up as gas escapes from the viscous lava. The eruptions can be explosive, leading to pyroclastic flows and ash fall, but the lava itself does not flow very far from the source due to its thick consistency. In contrast, stratovolcanoes also have the potential for violent eruptions but typically have more fluid lava that can travel greater distances. Cinder cones generally produce less explosive eruptions and consist of ejecta that does not consolidate into explosive events like those seen with cryptodomes. Shield volcanoes primarily have lava that flows easily and results in broad, gently sloping structures, rather than explosive eruptions. Understanding these distinct characteristics helps clarify why cryptodomes are recognized for their violent eruptions yet limited lava flow, setting them apart from the other types of volcanoes listed.