Krakatoa, Kilauea, and Crater Lake are examples of what volcanic feature formed when the magma chamber beneath a volcano empties?

• A. Caldera
• B. Crater
• C. Vent
• D. Fissure

Answer: (A)

Krakatoa, Kilauea, and Crater Lake are all notable examples of calderas, which are large depressions formed when the magma chamber beneath a volcano is partially or completely emptied. When a significant eruption occurs, the emptying of the magma chamber can lead to the ground above it collapsing into the space left behind, creating a caldera.

This process can result in a depression that is significantly larger than the original volcanic cone. Calderas are often the sites of subsequent volcanic activity, and may later fill with water, forming lakes, as seen in the case of Crater Lake in Oregon.

The distinction between a caldera and other volcanic features such as craters, vents, or fissures is significant. A crater is typically a smaller bowl-shaped depression that forms around the vent from which lava erupts; it does not involve the large-scale collapse associated with a caldera. Vents are openings in the Earth's surface through which volcanic materials can escape, while fissures are cracks in the ground from which lava can flow, but they do not create the expansive depressions characteristic of calderas.

Thus, the correct classification of Krakatoa, Kilauea, and Crater Lake as calderas highlights