Volcanic hazards Flashcards
1
Q
Volcano
A
- Conical mountain created by extrusive materials which emerge or are ejected from a central vent or crater
2
Q
Where are they found?
A
- Clustered, long narrow belts along plate boundaries at Constructive and Destructive
- Found in the middle of plates = Hot spots
3
Q
Volcanoes classified
A
- Volcanoes activity
- The eruption
- The magma
- The magnitude
4
Q
Volcanoes activity
A
- Active
- Dormant
- Extinct
5
Q
Eruption
A
- Gentle and regular
- Dangerous and explosive
6
Q
Magma
A
- Viscosity
- How acidic
- Amount of pressure
7
Q
Magnitude
A
- VEI scale
8
Q
Composite volcano
A
Subduction zones;
- magma is v acidic
- Thick and viscous
- Not as hot
- High levels of silica
- High gas levels = explosive
9
Q
Shield volcano
A
Constructive;
- Volcanoes and magma is basaltic
- Less viscous
- V runny
- Much hotter
- Explosions more gentle and more frequent
10
Q
How are volcanos measured?
A
- VEI - Volcano explosivity index
- Logarithmic scale from 0 to 8
1 = gentle 4 = cataclysmic 8 = mega-colossal
Uses;
- Eruption cloud height
- Volume of products erupted
- More subjective qualitative observations
