Volcanoes Volcanoes Student: Lưu Thị Toán Class: K52 geography Hanoi University of science • Firstly, I will introduce 2 ways of approaching volcanoes: in the past and at the present. • Then, I will give you an overview about volcanoes: their locations on the earth and how they erupts What do modern scientists think of What do modern scientists think of volcanoes? volcanoes? Today scientists can explain about volcanoes, but they also must guess about what is happening inside the earth. There is still much for us to learn. The locations of volcanoes on the earth The locations of volcanoes on the earth - They are not just scattered anywhere, but are found in chains and groups. - Three quarter of earth’s volcanoes are in the ring of fire around the Pacific ocean. the ring of fire around the Pacific ocean. What causes volcanoes erupt? What causes volcanoes erupt? • Much of the material under the surface of the earth is melted rock called magma. • Heavy layer of rock push down on the magma. The magma escapes sideways or spread until it starts to push on the underside of the earth’s surface. • If there is a weak spot, the magma and its gases push right through the spot and explode into the air if there is a lot of gas. • The eruption is violent, if there is only a little gas, the eruption is mild. • The hole which forms at the top of the volcano is called a crater. • After the magma escapes to the earth’s surface, it is called lava. Much of the material under the surface of the earth is melted rock called magma. Heavy layer of rock push down on the magma. The magma escapes sideways or spread until it starts to push on the underside of the earth’s surface. If there is a weak spot, the magma and its gases push right through the spot and explode into the air if there is a lot of gas The eruption is violent, if there is only a little gas, the eruption is mild The hole which forms at the top of the volcano is called a crater After the magma escapes to the earth’s surface, it is called lava • The dust from the eruption moved high above the earth and traveled around the world at least 12 times. • For 2 years it formed a wall between the sun and the earth. Conclusion Conclusion • People continue living near them because volcanic soil is the most production on earth. • Scientists are observing volcanoes through the world. They hope that by studying the history of eruptions an the changes in a volcano before an eruption, they will be able to tell one is going to happen. • Humans have learnt to control many things about nature, but we can not control volcanoes. However, if we can know that an eruption is going to happen, many lives can be saved. THANK YOU FOR YOUR LISTENING . locations of volcanoes on the earth - They are not just scattered anywhere, but are found in chains and groups. - Three quarter of earth’s volcanoes are. about volcanoes: their locations on the earth and how they erupts What do modern scientists think of What do modern scientists think of volcanoes? volcanoes?