Here's how it happens:
* Eruption and Emptying: A massive volcanic eruption can empty the magma chamber beneath the volcano, removing the support that held the overlying structure.
* Collapse: The unsupported rock above the empty chamber can no longer withstand the weight and collapses inward, creating a large depression.
* Caldera Formation: The depression formed by the collapse is called a caldera. It's usually circular or oval-shaped and can be several kilometers in diameter.
Famous examples of calderas include:
* Crater Lake, Oregon, USA: Formed after the catastrophic eruption and collapse of Mount Mazama.
* Yellowstone Caldera, Wyoming, USA: A supervolcano that has erupted several times in the past, creating a massive caldera.
* Lake Toba, Indonesia: The site of a supereruption that nearly wiped out humanity tens of thousands of years ago.
Calderas can sometimes be filled with water, forming lakes. They can also be the site of further volcanic activity, with smaller eruptions occurring within the caldera itself.
