Pyroclastic material
Also called: Tephra · Topic: Interior of the Earth: Earthquakes, Volcanoes and the Layered Earth · NCERT: Class 11, Ch 3 "Interior of the Earth"
Meaning
Pyroclastic material is the broken rock thrown out during an explosive eruption. "Pyro" means fire and "clastic" means broken pieces. It includes rock fragments, ash, dust and volcanic bombs (lumps of lava that cool in the air). It comes from viscous, gas-rich lava that blasts apart instead of flowing. Layers of it, alternating with lava, build composite volcanoes. A hot, fast cloud of gas and pyroclastic material rushing down a volcano is a pyroclastic flow, one of the deadliest volcanic hazards.
Example
In AD 79, Mount Vesuvius near Naples, Italy, buried the Roman town of Pompeii under ash and pyroclastic flows.
Don't confuse with
- Lava: molten rock that flows. Pyroclastic material is solid pieces blasted into the air.
Related concepts
- Volcano
- Magma
- Lava
- Active volcano
- Shield volcano
- Cinder cone
- Composite volcano
- Caldera
- Supervolcano
- Flood basalt province