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VOLCANOES - Coggle Diagram
VOLCANOES
Types of volcanoes
ACTIVE VOLCANOES:
These are the volcanoes which are presently in active state and have erupted in the recent past.
DORMANT VOLCANOES:
These volcanoes have not erupted in recent historical period. They are regarded as "sleeping volcanoes" and may become active at any time.
EXTINCT:
These are the types which have not erupted in the present geological period and are not likely to become active again.
Products of volcanoes
1.Magma and Lava-
The molten rock material inside the earth is known as magma.
When it reaches the surface it is known as lava
2.Solid Particles-
The solid fragments are rock pieces known as pyroclasts. The dine particles are called dust. The small stone sized particles are called lapilli.
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Structure of a volcano
Vent: The lava flows out through an opening in the earth's crust called Vent. The opening is usually like a circular pipe.
Volcanic Cone: The erupted fluid material being hot collects around the vent and begins to cool gradually and solidifies. The accumulation of material around the vent gives to the volcano its typical cone-like shape known as the Volcanic cone.
Effects of volcanoes
Constructive Effect
- Landforms - Numerous types of landforms are created due to cooling and solidification of magma below the earth's surface and lava on the earth's surface. The landforms created on earth's surface are called Extrusive Landforms.
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b. Volcanic Mountains - Volcanic mountains are the most diverse because there are great differences in volcanic eruptions as well as the materials they throw up.
c.Volcanic Plains - These plains are vast and smooth formed by extensive volcanic flooding from volcanic centers.
d. Cadlera Lake, e. Hot springs, f. Geysers* learn
Destructive Effect
-Agricultural fields are covered with layers of volcanic ash and dust making them unsuitable for cultivation.
-Huge clouds are formed after the eruption of volcanoes causing heavy rains which result in floods and landslides.
-Volcanoes also emit poisonous gases which pollute the environment and cause health problems