QUIZ – 2020: INSIGHTS STATIC , 21 June 2021 -Geography – INSIGHTSIAS

Solution: c)

General factors responsible for the origin of Cyclones in Bay of Bengal region are:

1. Large sea surface with temperature higher than 27° C.
2. Presence of the Coriolis force enough to create a cyclonic vortex.
3. Small variations in the vertical wind speed.
4. A pre-existing weak low-pressure area or low-level-cyclonic circulation.
5. Upper divergence above the sea level system.

Solution: a)

What exactly is a polar vortex?

It is described as a whirling cone of low pressure over the poles that is strongest in the winter months due to the increased temperature contrast between the polar regions and the mid-latitudes, such as the US and Europe.

Features:

• The polar vortex spins in the stratosphere.
• Usually, when the vortex is strongest, cold air is less-likely to plunge deep into North America or Europe. In other words, it forms a wall that protects the mid-latitudes from cold Arctic air.
• But occasionally, the polar vortex is disrupted and weakens, due to wave energy propagating upward from the lower atmosphere. When this happens, the stratosphere warms sharply in an event known as sudden stratospheric warming, in just a few days, miles above the Earth’s surface.
• The warming weakens the polar vortex, shifting its location somewhat south of the pole or, in some instances, ‘splitting’ the vortex up into ‘sister vortices’.

Solution: b)

Earth’s interior is made of different kinds of materials. Each of those materials are different from each other by their physical and chemical properties, such as temperature, density etc. Unique layers are there according to their characteristics inside the earth. All those layers are separated from each other through a transition zone. These transition zones are called discontinuities.

There are five discontinuies inside the earth.

• Conrad Discontinuity:  Transition zone between SIAL and SIMA.
• Mohorovicic Discontinuity:  Transition zone between the Crust and Mantle.
• Repiti Discontinuity: Transition zone between Outer mantle and Inner mantle.
• Gutenberg Discontinuity: Transition zone between Mantle and Core.
• Lehman Discontinuity: Transition zone between Outer core and Inner core.

Solution: d)

It was Alfred Wegener—a German meteorologist who put forth a comprehensive argument in the form of “the continental drift theory” in 1912. This was regarding the distribution of the oceans and the continents.

Wegener suggested that the movement responsible for the drifting of the continents was caused by pole-fleeing force and tidal force. The polar-fleeing force relates to the rotation of the earth. You are aware of the fact that the earth is not a perfect sphere; it has a bulge at the equator. This bulge is due to the rotation of the earth. The second force that was suggested by Wegener—the tidal force—is due to the attraction of the moon and the sun that develops tides in oceanic waters. Wegener believed that these forces would become effective when applied over many million years. However, most of scholars considered these forces to be totally inadequate.

Solution: a)

Tsunamis are giant waves caused by earthquakes or volcanic eruptions under the sea. Out in the depths of the ocean, tsunami waves do not dramatically increase in height. But as the waves travel inland, they build up to higher and higher heights as the depth of the ocean decreases.

It depends on Ocean depth rather than the distance from the source of the wave. Tsunami waves may travel as fast as jet planes over deep waters, only slowing down when reaching shallow waters.