Volcanoes

Question 1

What different states do we find volcanoes in?

Answer 1

Active - liable to erupt at any time eg mt etna
Dormant (sleeping) volcano - not erupted for many years eg mt Pinatuba erupted in 1991 after 500 years dormancy
Extinct - has not erupted for many thousands or millions of years eg Edinburgh

Question 2

What comes out of a volcano?

Answer 2

Magma - molten rock beneath the earth’s surface
Lava - molten rock emitted from a volcano
Lava bombs - round pieces of lava that solidify in mid air prior to hitting the ground
Ash - fine grained material made up of tiny pieces of rock and lava, can be blown over long distances by wind
Mudflow/Lahar - mudflow made up of ash, rain water, snow melt
Pyroclastic flow - fast downhill flow of hot gas, ash and pumice and volcanic bombs which may travel up to 200km/hr - approx 800 Degrees

Question 3

What are the types of volcanoes?

Answer 3

Composite

Shield

Question 4

What are the key characteristics of a composite volcano?

Answer 4

1. Steep slopes
2. More explosive and violent
3. Acid lava
4. Constructive plate margin eg mid Altantic ridge
5. Not as wide as shield volcanoes and quite tall

Question 5

What are the key characteristics of a shield volcano?

Answer 5

1. Gentle slopes
2. Quite wide and low
3. Just lava
4. Destructive plate margin eg NASCA/South America plate margin
5. Non - violent

Question 6

What are some effects of volcanic sites?

Answer 6

Fertile soils
Geothermal energy
Tourism
Precious minerals

Question 7

Explain how fertile soils develop near volcanoes?

Answer 7

Volcanic rock and ash rich in minerals in magma under surface

Rocks weathered and broken down releasing minerals into soil

Some of best farming soil on the planet

Eg Mt Vesuvius in Italy and Mt Elgon in Uganda

Question 8

Explain how geothermal energy arises at volcanoes?

Answer 8

This is heat energy from the earth
The steam drives turbines and produces electricity for homes
Iceland and New Zealand use this a lot - 2/3rds of Icelands electricity

Question 9

Explain how precious minerals appear at volcanoes?

Answer 9

Lots of minerals in magma eg tin, silver, copper, gold & diamonds
Most metallic minerals mined are from extinct volcanoes
Volcanoes are ideal for mining

Question 10

Why is tourism popular near volcanoes?

Answer 10

Attract millions of visitors all year round unlike skiing
Examples of extreme nature even if just puffing out steam
Tourists create jobs in shops, hotels, restaurants, etc
Related interesting features like hot springs, geysers, glaciers, eg in Iceland