Volcanic Eruption Features Flashcards
What is lava?
Lava is magma that erupts to the surface.
What are the characteristics of lava?
Lava can be thin and runny or thick and slow-moving, depending on the composition of the magma.
What is ash in the context of volcanic eruptions?
Ash is pulverised solid lava that measures less than 2 mm in diameter.
How far can volcanic ash travel?
Ash can be ejected into the atmosphere and travel thousands of kilometres.
What is a pyroclastic flow?
A pyroclastic flow is a fast-moving, very hot cloud of poisonous gases mixed with ash.
What are the average speeds of pyroclastic flows?
Pyroclastic flows average speeds of about 100 km/h but can move at up to 700 km/h.
What are lahars?
Lahars are fast-moving mudflows created when snow and ice on a volcano melt and combine with ash.
What causes earthquakes during volcanic eruptions?
Earthquakes are caused by magma rising to the surface through the vents, increasing pressure on the Earth’s crust.
What are volcanic bombs?
Volcanic bombs are fragments of molten rock ejected from the volcano.
What is the size range of volcanic bombs?
Volcanic bombs range from 60 mm to 5 m in diameter.
