Understanding What a Caldera Is
A caldera is a large, bowl-shaped depression formed when a volcano erupts and the emptied magma chamber collapses. This collapse creates a wide, circular basin on the surface.
How Calderas Form
After a major eruption, the magma chamber beneath the volcano loses support as molten rock escapes. Without pressure holding the ground up, the surface sinks, producing a caldera that can span several kilometers.
Examples of Calderas
Some of Earth’s most famous volcanic landscapes are calderas.
- Yellowstone Caldera in the United States
- Crater Lake in Oregon, formed by Mount Mazama
- Toba Caldera in Indonesia, site of a massive eruption
- Ngorongoro Crater in Tanzania, shaped by ancient collapse
Why Calderas Matter
Calderas reveal the scale of past volcanic events and help scientists study magma systems. They also host lakes, fertile soils, unique ecosystems, and geothermal activity.
Key Characteristics of Calderas
- Formed by collapse after major volcanic eruptions
- Wide, circular depressions often several kilometers across
- Can fill with lakes or host renewed volcanic activity
- Important markers of large-scale geological processes
The Simple Takeaway
A caldera is a huge volcanic depression created when the ground collapses after an eruption. These dramatic structures reveal powerful volcanic activity from Earth’s past.