Information on volcano for schoolPresentation Transcript
Information on volcanoes Social studies project
Volcano – What is it A volcano is an opening in the planet's surface or crust, which allows hot magma, volcanic ashes and gases to escape from below the surface. The most common perception of a volcano is of a conical mountain, spewing lava and poisonous gases from a crater at its summit.
Volcano – Erupted Materials Magma is molten rock within the Earth's crust. When magma erupts through the earth's surface it is called lava. Lava can be thick and slow-moving or thin and fast-moving. Rock also comes from volcanoes in other forms, including ash (finely powdered rock that looks like dark smoke coming from the volcano), cinders (bits of fragmented lava), and pumice (light-weight rock that is full of air bubbles and is formed in explosive volcanic eruptions - this type of rock can float on water).
Difference between lava and magma Magma is liquid rock inside a volcano. Lava is liquid rock (magma) that flows out of a volcano. Fresh lava ranges from 1,300° to 2,200° F (700° to 1,200° C) in temperature and glows red hot to white hot as it flows.
How many volcanoes are therein the world? There are around 1510 'active' volcanoes in the world. We currently know of 80 or more which are under the oceans.
What causes volcanoes to erupt? The Earth's crust is made up of huge slabs called plates, which fit together like a jigsaw puzzle. These plates sometimes move. Between the Earth's crust and the mantle is a substance called magma which is made of rock and gases. When two plates collide, one section slides on top of the other, the one beneath is pushed down. Magma is squeezed up between two plates. Did you know? Volcanoes are like giant safety valves that release the pressure that builds up inside the Earth.
Where are a large number of volcano found? What is the Ring of Fire? Over half of the world’s volcanoes arise in a belt around the Pacific Ocean called the Ring of Fire. Which is the largest volcanic mountain? Mauna Kea which is also worlds tallest mountain is the largest volcanic mountain.
Effect of Volcanoes on people and the environment As well as the danger from the hot lava, an erupting volcano can trigger are life threatening things. tsunamis flash floods earthquakes mud flows rock falls.
People and Volcanoes Volcanoes can have a very serious effect on the lands and people around them when they erupt. Buildings are destroyed and people are made homeless. People are killed. Clouds of ash cover plants making them inedible. Poisonous gases kill people and animals. Dust causes pneumonia and illnesses to the survivors. Dark skies, severe winds and heavy rains may follow an eruption for months afterwards. .
Fact File One in 10 people in the world live within 'danger range' of an active volcano. People can get used to living near a volcano, but it is always a little dangerous. Scientists have estimated that at least 200,000 persons have lost their lives as a result of volcanic eruptions during the last 500 years. People set up homes on the slopes of volcanoes because of the rich, fertile soil produced
Social studies project From Class 7th C group B on Volcano