Glossary
Caldera
A caldera is a large circular depression, several to tens of kilometres across. It forms when the roof of the magma chamber collapses after an eruption has emptied it.
The largest calderas record the most violent eruptions in Earth's history, like Toba in Indonesia about 74,000 years ago. Some, like the Phlegraean Fields near Naples, are closely monitored.
Examples on the Map
Other Definitions
- Tectonic Plate
- Subduction
- Mid-Ocean Ridge
- Transform Fault
- Fault
- Earthquake, Epicentre and Hypocentre
- Magnitude
- Intensity (Mercalli Scale)
- Aftershock
- Tsunami
- Active Volcano
- Stratovolcano
- Shield Volcano
- Volcanic Explosivity Index (VEI)
- Pyroclastic Flow
- Lahar
- Hotspot
- Tropical Cyclone, Hurricane, Typhoon
- Saffir-Simpson Scale
- Aurora and Kp Index