Glossary
Mid-Ocean Ridge
A ridge is a long underwater mountain range where two plates move apart. Magma rises into the gap, cools and continuously builds new ocean floor. Ridges form the longest relief on the planet, about 65,000 km.
Earthquakes there are frequent but usually moderate. Iceland is a rare place where a ridge, the Mid-Atlantic Ridge, rises above the sea, which explains its intense volcanism.
Examples on the Map
Other Definitions
- Tectonic Plate
- Subduction
- Transform Fault
- Fault
- Earthquake, Epicentre and Hypocentre
- Magnitude
- Intensity (Mercalli Scale)
- Aftershock
- Tsunami
- Active Volcano
- Stratovolcano
- Shield Volcano
- Caldera
- Volcanic Explosivity Index (VEI)
- Pyroclastic Flow
- Lahar
- Hotspot
- Tropical Cyclone, Hurricane, Typhoon
- Saffir-Simpson Scale
- Aurora and Kp Index