Volcanoes Flashcards
What’s a vent?
Secondary vent?
Vent- the pipe through which magma rises
Secondary vents - a smaller vent on side of volcano
What’s a crater?
Bowl shaped depression at top of volcano
What are fumaroles?
A pipe through which gases rise (eg:sulphur dioxide)
What are volcanic bombs?
Chunks of molten lava thrown into air.
Describe the distribution of volcanoes
- unevenly spread throughout Southern and Northern hemisphere
- they’re in lines and belts that sit on plate boundaries
- at edges of Pacific Ocean there’s volcanoes close together in linear patterns
- cluster of volcanoes in Iceland
Name an anomaly of volcanic distribution
In Hawaii there’s a volcano that stands alone (not on plate boundary) due to lava flow underground. This is called a hotspot
Where do volcanoes occur?
Constructive and destructive plate boundaries
Name the three types of volcanoes
Composite volcanoes
Shield volcanoes
Done volcanoes
What is a composite volcano?
Built up by many layers of hardened lava, pumice and volcanic ash. Have crater on top. They have steep sides and are tall with quiet eruptions. High velocity lava that hardens quickly before spreading. Form at DESTRUCTIVE BOUNDARIES.
What’s a shield volcano?
A shield volcano is built of almost entirely lava flow. They’re wide and low-lying with gently sloping sides. They erupt highly fluid lava which travels further before it hardens. They form at CONSTRUCTIVE BOUNDARIES
What are the main features of dome volcanoes?
- very tall
- steep sides
What’s a magma chamber?
Where magma is stored underground
