Volcano Basics
What is the name of the opening through which magma escapes from beneath Earth's surface?
Vent
Question: According to the typical young-earth creationist geological interpretation taught in this chapter, when did most volcanoes form?
Question: Which type of volcano has broad, gently sloping sides formed by many layers of flowing lava?
Shield volcano
Question: What is the underground molten rock called before it reaches Earth's surface?
Magma
Question: What type of energy comes from the internal heat of the Earth?
Geothermal energy
Question: What are the three main classifications used to describe a volcano's activity?
Active, dormant, extinct
Question: What general term describes fragments of volcanic material thrown into the air during an eruption?
Tephra
Question: What type of volcano is built primarily from loose volcanic fragments such as cinders, ash, and bombs?
Question: What do geologists call a large mass of igneous rock that forms when magma cools and solidifies beneath Earth's surface?
Pluton
Question: What is the name of a natural opening in the ground that releases hot gases and steam?
Fumarole
Question: What is the name of the large volcanic region surrounding much of the Pacific Ocean, known for frequent earthquakes and eruptions?
Ring of Fire
Question: What is the name of a volcanic mudflow that can travel down a volcano's slopes and bury nearby communities?
Lahar
Question: A volcano has steep sides and is built from alternating layers of hardened lava and volcanic debris. What type is it?
Stratovolcano
Question: What is the difference between a dike and a sill in terms of their orientation?
A dike exists between rock layers, a sill forms parallel to existing layers
Question: What type of underground organism produces food using chemical energy around deep-ocean hydrothermal vents called black smokers?
Bacteria
Question: A volcano has not erupted in recorded history, but scientists believe it could erupt again. What activity classification best describes it?
Dormant
Question: During an eruption, a mixture of extremely hot gases, ash, and rock fragments rushes down a volcano at high speeds. What is this dangerous event called?
Pyroclastic flow
Question: A volcanic eruption occurs beneath the ocean. As the lava cools quickly in the surrounding water, it forms rounded, pillow-shaped structures. What are these structures called?
Pillow lava
Question: A large body of magma pushes upward between existing rock layers, bending the layers above it into a dome shape. What is this underground structure called?
Laccolith
Question: What causes the water in a geyser to become hot enough to erupt periodically?
Underground water is heated by hot rocks with magma, builds pressure, and periodically expelled
Question: What are two ways scientists can determine whether a volcano that has not erupted recently may still be active?
Looking for signs of seismic activity beneath the volcano and monitoring other signs of volcanic activity such as gas emisisons or ground swelling
Question: Two types of magma have different silica contents. Which one generally flows more slowly: magma with high silica content or magma with low silica content? Explain why.
High-silica magma
Question: A volcano erupts explosively, and afterward much of its central cone collapses into the emptied magma chamber, leaving a huge bowl-shaped depression. What is this depression called?
Caldera
Question: A volcano's underground magma chamber feeds smaller openings along its sides. What are these smaller volcanic openings called, and what type of cone can they help form?
Parasitic vents
Question: The eruption of Mount Tambora caused unusual weather conditions around the world. What was one major worldwide effect of this eruption?
Global cooling and unusual weather, including the 1816 "Year Without a Summer."