Volcanoes 🌋 Flashcards
What is the definition of an
Active Volcano 🌋?
Recently erupted and likely to erupt again.
What is the definition of a
Dormant Volcano 🌋?
A volcano that has erupted within the last two millennia, but not in the recent past.
What is the definition of an
Extinct Volcano 🌋?
When a volcano is unlikely to erupt again.
What do most volcanoes occur in?
Most volcanoes occur in narrow belts or grouped in small clumps.
What are volcanoes?
Volcanoes are openings/VENTS in the ground. Magma/molten rock forces its way to the surface through these.
What is molten rock under the ground called?
MAGMA
What is molten rock above the ground surface called?
Lava
What is the definition of
volcanic bombs.
Fragments of ash and dust that are ejected into the atmosphere during an eruption.
What happens when a volcano erupts?
When a volcano erupts, magma from beneath the surface rises up the vent to the crater. Then, it explodes into the air as ash, dust, and volcanic bombs or flows out as molten rock.
What happens when a volcano erupts?
When a volcano erupts, magma from beneath the surface rises up the vent to the crater. Then, it explodes into the air as ash, dust, and volcanic bombs or flows out as molten rock.
Why are volcanoes hazards?
- Explosion
- Materials – Numerous types of material are ejected by volcanoes such as lava, pyroclastic material and gases.
- Lava rarely threatens life as its flow is relatively predictable but it does destroy property by swamping buildings or starting fires.
- Volcanic gases are often hot and toxic
- Landslides – Volcanoes often bulge as pressure builds up beneath them. This deformation of the steep slope may cause landslides.
- Lahars
- These are volcanic mudflows.
- Hot ash mixes with river water or heavy rain. It can flow as a thick hot mixture at great speed.
Why do people choose to live near volcanoes?
- Fertile Soil
- Some but not all lava flows and ash falls can be weathered into rich fertile soils. Soils based on basic lavas or ash deposits rich in potassium or phosphorus are highly valued.
- Mineral deposits
- Volcanic deposits provide a wide variety of industrial materials and chemicals including sulphur, pumice, arsenic and boric acid.
- Metal ores form in seams under the ground as gas is given off by the cooling lava.
- Diamonds are formed deep in volcanic zones along narrow channels called kimberlite pipes.
What are plates?
Large sections of the earth’s crust
Why are volcanoes found near plate boundaries?
The movement of faults at plate boundaries can provide a convenient pathway for magma to reach the surface.
