Vulcanism and Earthquakes

Question 1

1. Magma while thrusting its way up to the surface may cool and solidify within the crust as plutonic rocks resulting in-
2. Magma that reach the surface and solidify-

Answer 1

1. Intrusive landforms

2. Extrusive landforms

Question 2

Rocks formed by either plutonic or volcanic activity are called-

Answer 2

Igneous rocks

Question 3

When an intrusion of molten magma is made horizontally along the bedding planes of sedimentary rocks, the resultant intrusion is called a-

Answer 3

SILL

Question 4

Intrusions when injected vertically as narrow walls of igneous rocks within the sedimentary layers are termed as-

Answer 4

DYKES

Question 5

Igneous intrusions on larger scale are the various types of -

Answer 5

LITHS: laccoliths,lopoliths,phacoliths and batholiths

Question 6

Igneous mound with a dome shaped upper surface and a level base fed by a pipe-like conduit from below -

Answer 6

Lacolith

Question 7

Igneous intrusion with a saucer shape-

Answer 7

Lopolith

Question 8

Igneous intrusion with lens shaped mass of igneous rocks occupying the crest of an anticline or the bottom of a syncline and being fed by a conduit from beneath-

Answer 8

Phacolith

Question 9

A huge mass of igneous rocks, usually granite, which after removal of the overlying rocks forms a massive and resistant upland region .

Answer 9

Batholith

Question 10

Volcanic activity is closely connected with________, particularly where the zones of weakness due to ____________.

Answer 10

crustal disturbances, deep fault or mountain folding.

Question 11

The magma is heavily charged with gases such as-

Answer 11

carbon dioxide, sulphurated hydrogen, and small proportions of nitrogen, chlorine.

Question 12

The gases and vapour increase the mobility and explosiveness of the lavas, is the statement true?

Answer 12

true

Question 13

The gases and vapour emitted through the orfice of a volcano during a volcanic erruption known as-

Answer 13

vent

Question 14

Types of lavas-

Answer 14

Basic lavas and acid lavas

Question 15

are the statements true about basic lavas-

1. These are the hottest lava and are highly fluid.
2. rich in silica and poor in iron and magnesium.
3. flow quietly and are very explosive.
4. Flow readily, spreading out as thin sheets

Answer 15

1. true
2. False. Rich in iron n magnesium, poor in silica
3. Flow quietly but are not very explosive.
4. true

Question 16

Are the statements correct about acid lava-

1. These lavas are highly viscous with low melting point.
2. Low percentage of silica
3. They are light coloured and of low density.
4. They flow slowly

Answer 16

1. highly viscous with high melting point.
2. high percentage of silica
3. true
4. true

Question 17

The rapid congealing of lava in the vent obstructs the flow of the out-pouring lava , resulting in -

Answer 17

Bomb explosions or pyroclasts

Question 18

Volcanoes frequently erupt or at least when they have erupted within recent times-

Answer 18

Active volcano

Question 19

Volcanoes known to erupt and shows sign of possible eruption-

Answer 19

Dormant volcanoes

Question 20

Volcanoes that have not erupted at all in historic times but retain the features of volcanoes-

Answer 20

Extinct volcano

Question 21

Which type of lava or acid lava flowing for long distances produces extensive lava plains and basalt plateaux-

Answer 21

The fluid basic lava.

Question 22

Lava domes or shield volcanoes with gently rising slopes and broad , flattened tops are build up by-

Answer 22

Highly fluid lava

Question 23

Less fluid or high fluid lava explodes violently?

Answer 23

Less fluid

Question 24

Lava tounges are formed in -

Answer 24

valleys, when viscous lava flow through them.

Question 25

Composite cones can be seen in-

Answer 25

Highest and most common volcanoes

Question 26

Composite cone volcanoes are often called-

Answer 26

Strato volcanoes

Question 27

From the main conduit, subsidiary dykes or pipes may reach the surface as feeders to -

Answer 27

Parasitic cones

Question 28

Which composite volcano is known as LIGHTHOUSE OF MEDITERRANEAN -

Answer 28

Mt. Stromboli

Question 29

Some volcanoes have greatly enlarged depressions called-

Answer 29

Caldera

Question 30

Water collect in caldera forming -

Answer 30

Caldera lakes

Question 31

Ex of caldera lake-

Answer 31

Lake toba in sumatra

Question 32

volcanoes closely related to region like-

Answer 32

intensely folded or faulted

Question 33

Two-thirds of the world’s volcanoes found in circum pacific region known as-

Answer 33

Pacific Rings of Fire

Question 34

Do himalayas have active volcanoes?

Answer 34

No

Question 35

What are geysers?

Answer 35

They are fountains of hot water amd superheated steam that amy spout up to a height of 150 feet from the earth beneath. The jet of water is usually emitted with an explosion and is often triggered off by gases seeping out of the heated rocks.

Question 36

The world’s best known geyser-

Answer 36

OLD FAITHFUL in Yellowstone National Park.

Question 37

Hotsprings are also known as-

Answer 37

Thermal springs

Question 38

what are hotsprings?

Answer 38

Water sinks deep enough beneath the surface to be heated by the interior forces. The water rises to the surface without any explosion.

Question 39

Does spring contain dissolved minerals which may be of medical values?

Answer 39

yes

Question 40

Which are more common, hotsprings or geysers?

Answer 40

Hotsprings

Question 41

Minor earth tremors(earthquake) are caused by-

Answer 41

Gentle waves of vibration within earth’s crust.

Question 42

Major earth quakes are caused by-

Answer 42

Movement along faults.

Question 43

The giant tidal waves produced by earthquakes are known as-

Answer 43

Tsunamis

Question 44

70% of earthquakes occur in the -

Answer 44

Circum specific belt