Dead Volcanoes
Volcanoes that no longer have the capacity to erupt.
Debris Avalanche
A rapid and unusually sudden sliding or flowage of unsorted masses of rock and other material driven by gravity.
Dike
A sheetlike body of igneous rock that cuts across layering or contacts in the rock into which it intrudes.
Dome
A steep-sided mass of viscous (sticky) lava extruded from a vent. The dome is either spiny, rounded or flat on top with a rough and blocky surface. The steep sides of lava domes often become unstable and can collapse, causing a type of small pyroclastic flow known as a block and ash flow. Lava domes are abundant in the Lesser Antilles and their collapse has caused significant loss of life
Dormant
May be used to describe a volcano that has not erupted in the last 10,000 years but can erupt in the future. Most scientists either use the term active or inactive rather than dormant.
Duration
Time interval between the first and last peaks of strong ground motion above a specified amplitude.