Geography GK Questions with Answers – Page 80

A seismograph, also called a seismometer, senses the shaking of the ground and draws it as a wavy line called a seismogram.

Granite forms when magma cools slowly deep inside the crust, so it is an intrusive, or plutonic, igneous rock. The slow cooling lets large crystals of quartz, feldspar and mica grow, which is why granite has a coarse, grainy look you can see with the naked eye.

Venus is wrapped in a dense blanket of carbon dioxide topped by thick white and yellow clouds of sulphuric acid, which is why it shines so brightly in our sky.

Because of the gravitational pull of the moon and the sun, together with the centrifugal effect of the earth's rotation, most coasts see the sea rise and fall twice in a day.

In the traditional Indian reckoning the year is divided into six seasons of two months each, and Hemant, the pre-winter, falls in the months of Agrahayana and Pausha — that is, November and December.

In the summer months the tropical easterly jet stream blows over peninsular India at about 14°N, some 15 km above the ground, and it moves from east to west.

Ceres is the only dwarf planet that orbits inside the main asteroid belt, the ring of rocky bodies between Mars and Jupiter.

Nor'westers are violent pre-monsoon thunderstorms that strike eastern India, especially West Bengal and Assam, in the afternoons and evenings of April and May.

Bhopal stands at about 23.3° North, so of the four cities it lies nearest to the 24° parallel.

Nife is formed from the chemical symbols of nickel and iron, the two metals believed to make up the central part of the planet, and the flow of that metal in the liquid outer core is what generates the Earth magnetic field.

Coal is a sedimentary rock formed from buried plant matter, and prolonged heat and pressure drive off its volatile content and rearrange the carbon, first into harder anthracite and finally into graphite, a metamorphic rock of nearly pure carbon.

It lies in the upper mantle just below the rigid outer shell, is weak and partly molten, and is the main source of the magma that reaches the surface through volcanoes; the plates slide over it.

The core bends P waves sharply and stops S waves altogether, so a belt of the Earth surface receives neither type of wave from a given earthquake.

Granite forms when magma cools slowly deep below the surface, which gives the crystals time to grow, so the rock is coarse and speckled.

It marks the change from the molten outer core to the solid inner core, and is named after Inge Lehmann, who deduced from the behaviour of earthquake waves that the innermost part of the planet is solid.

Almost half the weight of the crust, about 46.6 per cent, is oxygen, because it is locked into the silicate minerals of which nearly all crustal rocks are made rather than existing as free gas.

They are built up layer by layer as sediment settles over the remains of living things and hardens gently, so shells, bones and plant matter survive as fossils.

The Deccan Trap was formed by vast fissure eruptions in which lava spread over the surface and cooled quickly, giving a fine-grained extrusive igneous rock, basalt.

Limestone is a sedimentary rock made largely of calcium carbonate, and when heat and pressure recrystallise it without melting it, the result is marble, the stone used in the Taj Mahal and in the Dilwara temples.

They are transverse waves, in which particles vibrate at right angles to the direction of travel, and such motion cannot be sustained in a fluid, so S waves die out at the outer core.