Extreme Earth Geography Slide6

Extreme Earth

Learning Objective: To find out what volcanoes are and how they are formed.

NEXT www.planbee.com Which of these is the odd one out?

Mount Redoubt, USA Mount Everest, Nepal

Mont Blanc, France/Italy Mount Aconcagua, Argentina

BACK NEXT www.planbee.com The odd one out was Mount Redoubt. The others are all mountains but Mount Redoubt is a volcano. Mount Redoubt, USA

What is the difference between a mountain and a volcano?

BACK NEXT www.planbee.com Have a look at the photos of volcanoes on the next slides. For each one, discuss what you think is happening...

BACK NEXT www.planbee.com White Island, New Zeland

BACK NEXT www.planbee.com Krakatau, Indonesia

BACK NEXT www.planbee.com Thórsmörk, Iceland

BACK NEXT www.planbee.com Eyjafjallajökull, Iceland

BACK NEXT www.planbee.com Tungurahua, Ecuador

BACK NEXT www.planbee.com Jazirat al-Tair, Yemen

BACK NEXT www.planbee.com Kīlauea, Hawaii

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mantle The Earth is made up of several layers. Underneath the crust is the mantle. This outer core layer consists of semi-molten rock. inner core In some areas, the mantle becomes so pressurised that it becomes a liquid called magma. The liquid then escapes through vents in the crust. This is what a volcano is.

The magma builds up in a magma chamber until the pressure is too much and it has to be released.

BACK NEXT www.planbee.com When a volcano erupts, it releases a violent explosion. Clouds of ash and poisonous gas are emitted, as well as lava. Lava is the liquid rock that was built up in the magma chamber. It becomes lava when it leaves the volcano.

BACK NEXT Mount Etna, Italy www.planbee.com Volcanic ash is made up of tiny particles of rock, minerals and volcanic glass. Wind can carry this ash across a great distance. In 2010, a volcanic eruption in Iceland caused chaos across Europe. The ash spread so far that airports across Europe had to close due to hazardous conditions. Eyjafjallajökull, Iceland BACK NEXT www.planbee.com When the lava flowing down a volcano cools, it becomes solid rock. This is how lots of volcanoes are formed. The rock cools over the eruption funnel, forming a cone shape. The volcanoes become taller and more like mountains with each eruption.

A good example of this is Mount Fuji in Japan.

BACK NEXT www.planbee.com Mount Fuji, like many other volcanoes, is active. This means that it has erupted in the last 10,000 years and that it is expected to erupt again some time in the future. Mount Fuji last erupted relatively recently in 1708.

BACK NEXT www.planbee.com A dormant volcano is a volcano that has not erupted in the last 10,000 years but that people expect will erupt again sometime in the future. Mount Kilimanjaro in Tanzania is a dormant volcano.

BACK NEXT www.planbee.com Attribution: https://commons.wikimedia.org/wiki/File:Mount_Boucherie_north_face.jpg An extinct volcano is a volcano that has not erupted in the last 10,000 years and is not expected to erupt again. There are hundreds of extinct volcanoes around the world, such as Mount Boucherie in Canada.

BACK NEXT www.planbee.com This map shows areas of volcanic activity around the world. What do you notice about how the volcanoes are placed?

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