Volcano Flashcards
Active Volcano
Volcano still erupting at frequent intervals. e.g: Mount Etna.
Volcano parts
Ash and dust (Volcanic bombs, Crater, Lava, Vent, Magma chamber/magma reservoir, Side vent, Parasitic cone.
Dormant Volcano
This volcano was quiet for a long time but may erupt again e.g Mount St. Helens.
Extinct Volcano
This volcano has died out and will not erupt again. e.g Slemish mountains in Co.Antrim.
Pacific ring of fire
A circle of volcanoes in the pacific.
It contains more than half of the world’s active volcanoes and some of the world’s major earthquakes.
How a volcano is formed
When two plates move apart a gap opens yp. Magma rises up from the mantle to fill the gap.
If the gap is a narrow opening or hole in the crust, this is called a vent.
Hot molten rock erupts from this vent and onto the surface, blasting material into the sky.
When magma reaches the surface it is known as lava.
Lava pours through the crater and flows down the side of the cone. It cools and hardens.
Lava flows and ash layers build up to form a cone-shaped mountain.
Advantages of a volcano
Farming: Volcanic rock, when broken down by the weather, make very fertile soil.
Electricity: Hot springs - e.g Iceland Water, heated by hot rocks beneath the surface, makes streams which can be used to make electricity. (geothermal energy)
Minerals and precious stones:
Valuable minerals such as good and diamonds are found near volcanoes.
Tourism: Mount vesubius and mt. etna in Italy attract tourists every year.
Disadvantages of volcanoes
Loss of life Smoke, ash, dust can cause health problems and disrupt air travel. Loss of property Can cause heavy rain/acid rain Damage/kill wildlife Damage to infrastructure Pollute lakes and rivers Forest fires Could cause huge waves if boulders are thrown into sea.
