Glossary
Subduction
Subduction happens when two plates converge and the denser one, almost always an oceanic plate, dives beneath the other and sinks into the mantle. The contact zone forms an ocean trench, such as the Mariana Trench.
Subduction zones produce the largest earthquakes on record, above magnitude 9, and the most destructive tsunamis. The sinking plate melts at depth and feeds chains of explosive volcanoes, as in Japan, Indonesia or the Andes. On the map, small triangles point to the overriding plate.
Examples on the Map
Other Definitions
- Tectonic Plate
- Mid-Ocean Ridge
- 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