Tài liệu sermina về núi lửa - Volcanoes

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 sideway

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

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

- 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?

• 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.

• 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