Geography [2 Mark Question Answer]

There are three types of volcanoes e.g. active volcano which is still active in erupting magma dormant volcano which erupts in uncertain intervals and extinct volcano which has stopped eruption permanently it is also called dead volcano.

Two types of landforms are :

1. Extrusive landforms :
   Extrusive landforms include crater composite cones caldere lava platforms.
2. Intrusive landforms :
   Intrusive landforms include dykes batholiths laccoliths volcanic hill etc.

A volcanic eruption is one of the main causes of earthquakes because volcanic earthquakes are caused by gas explosions. Such earthquakes occur either simultaneously with eruption or more commonly in the period preceding an eruption.

The molten rocks of vulcanicity are of considerable environmental significance other than soil fertility since it is the direct or indirect cause of several classes of landforms. Basic lava weather into more fertile soils.

The volcanoes and earthquakes are associated with each other as every volcanic activity takes place by shaking and breaking the weak crust which naturally creates tremors and earthquakes within the earth’s crust.

Basic lava cones are formed by liquid lava which expands and covers a large area while the Acid cones are formed by solid material e.g. ash cinders etc which heap up but do not cover large area and form a high conical hill as compared to broad and low volcanic deposits on the surface.

Laccoliths: Laccoliths are large lens-shaped intrusions which assume a dome shape. They vary in thickness and extent. When laccoliths are exposed on the surface they form low hills.
Lapoliths: Lapoliths is a saucer-shaped intrusive layer of solidified magma and sinks as shallow basins in rock-beds.

Folding and Faulting frequently go together because the stress on folding exceeds more than enough then folds break through fault line to two pieces slipping one upon another which is called faulting.

Internal processes are associated with tectonic forces resulting in drastic changes e.g. earthquakes volcanoes etc. External processes are carried on by natural agents of change e.g. water wind and ice which produce gradual changes.

Earth movements like Continental Drift theory changed the whole face of the earth into distinct continents and oceans of today with highest mountains plateaus plains drainage system and so on

Tectonic movements are changes through earth’s natural activities which are known as ‘diastrophism’. These movements are of two types e.g. vertical movement and horizontal movement.

Basic – type lava sheet weather into fertile soil e.g.Deccan trap soil. Other useful feature of volcanicity is that the precious minerals come out with the magma near the land surface e.g. diamond and gold etc.

Basic lava cones are formed by liquid lava which expands and covers a large area while the Acid cones are formed by solid material e.g. ash cinders etc which heap up but do not cover large area and form a high conical hill as compared to broad and low volcanic deposits on the surface.

The volcanoes and earthquakes are associated with each other as every volcanic activity takes place by shaking and breaking the weak crust which naturally creates tremors and earthquakes within the earth’s crust.

Laccoliths: Laccoliths are large lens-shaped intrusions which assume a dome shape. They vary in thickness and extent. When laccoliths are exposed on the surface they form low hills.

Lapoliths: Lapoliths is a saucer-shaped intrusive layer of solidified magma and sinks as shallow basins in rock-beds.

 

Crater	Caldera
The crater is the mouth of a volcano at the top of the vent with a normal outlet.	Caldera is a very large mouth of a volcano which is quite spacious due to the big amount and thrust of the eruption.

The earthquakes are distributed along with two major belts namely circum Pacific earthquake belt (Ring of fire) and the Mid-World, Mountain Earthquake belt along the great fold mountain zone.

Active volcanoes go on erupting magma continuously e.g. stromboli (North of Sicily). Dormant volcanoes erupt in accidental intervals e.g. Mt. Vesuvius in Italy. Extinct volcanoes stop eruption forever. e.g. Mt. Fujiyama in Japan.

The interior part of the earth is extremely hot temperatures up to 2000°C. in which every matter converts into a molten form. This molten material ‘magma’ always tries to burst out wherever it finds any crack or hole in the crust. The process of erupting out of magma is known as ‘vulcanism’.

Geysers are fountains of super heated steam and hot water that is usually emitted with an explosion trigged off by gases escaping from below

Most of the active volcanoes are formed along the fold mountains such as the Himalayas, The Alps, The Andes etc. Fold mountains have been formed by mountain building movements. These involve intense folding and faulting which mark lines of weakness on the surface. Most of the eruptions take place along these lines of weak.

Volcanic Dust: The finely pulverised fragments of rock are called volcanic ash.
Volcanic Ash: very fine particles which blow into the air are called volcanic dust.

Seismology: Seismology is the science of the study of earthquakes.
Volcanology: Volcanology is the science of the study of volcanic phenomena.