GEOLOGY

Detailed explanation-1: -Collectively, loose material thrown from a volcano is referred to as tephra. Individual fragments are referred to in general terms as pyroclasts, so sometimes tephra is also referred to as pyroclastic debris.

Detailed explanation-2: -Individual eruptive fragments are called pyroclasts ("fire fragments"). Tephra (Greek, for ash) is a generic term for any airborne pyroclastic accumulation. Whereas tephra is unconsolidated, a pyroclastic rock is produced from the consolidation of pyroclastic accumulations into a coherent rock type.

Detailed explanation-3: -The term tephra (ash) as originally defined was a synonym for pyroclastic materials, but it is now used in the more-restricted sense of pyroclastic materials deposited by falling through the air rather than those settling out of pyroclastic flows.

Detailed explanation-4: -Tephra is a general term for airborne pyroclastic material ejected during the course of a volcanic eruption (Thorarinsson, 1981). Extremely explosive eruptions may produce a blanket of tephra covering vast areas, in a period which can be considered as instantaneous on a geological timescale.

Detailed explanation-5: -Collectively, the fragments ejected during explosive eruptions are termed pyroclasts, meaning “fire-broken” from the ancient Greek. Pyroclasts may be ejected while still molten or partially molten, or may consist of solidified magma or of other rock fragments.