[Mission 2022] QUIZ – 2022: INSIGHTS STATIC QUIZ, 25 November 2021 – Geography – INSIGHTSIAS

Solution: c)

All-natural earthquakes take place in the lithosphere.

Earthquake waves are basically of two types — body waves and surface waves. Body waves are generated due to the release of energy at the focus and move in all directions travelling through the body of the earth. The body waves interact with the surface rocks and generate new set of waves called surface waves. These waves move along the surface. The velocity of waves changes as they travel through materials with different densities. The denser the material, the higher is the velocity.

The surface waves are the last to report on seismograph. These waves are more destructive. They cause displacement of rocks, and hence, the collapse of structures occurs.

Solution: a)

The Indian plate is moving at a speed of one centimetre per year towards the north and north-eastern direction and this movement of plates is being constantly obstructed by the Eurasian plate from the north.

As a result of this, both the plates are said to be locked with each other resulting in accumulation of energy at different points of time.

Excessive accumulation of energy results in building up of stress, which ultimately leads to the breaking up of the lock and the sudden release of energy causes earthquakes along the Himalayan arch.

Some of the most vulnerable regions are Jammu and Kashmir, Himachal Pradesh, Uttaranchal, Sikkim, and the Darjiling and subdivision of West Bengal and all the seven states of the northeast.

Solution: a)

Floods are relatively slow in occurrences and often, occur in well-identified regions and within expected time in a year.

Floods occur commonly when water in the form of surface run-off exceeds the carrying capacity of the river channels and streams and flows into the neighbouring low-lying flood plains.

At times, this even goes beyond the capacity of lakes and other inland water bodies in which they flow.

Floods can also be caused due to a storm surge (in the coastal areas), high intensity rainfall for a considerably longer time period, melting of ice and snow, reduction in the infiltration rate and presence of eroded material in the water due to higher rate of soil erosion.

Solution: d)

Two major categories of landslide prone regions can be established – high and low (or moderate).

Highly unstable, relatively young mountainous areas in the Himalayas and Andaman and Nicobar, high rainfall regions with steep slopes in the Western Ghats and Nilgiris, the north-eastern regions, along with areas that experience frequent ground-shaking due to earthquakes, etc. and areas of intense human activities, particularly those related to construction of roads, dams, etc. are included in the high risk zone.

Moderate to Low Vulnerability Zone: Areas that receive less precipitation such as Trans-Himalayan areas of Ladakh and Spiti (Himachal Pradesh), undulated yet stable relief and low precipitation areas in the Aravali (with stable rock structures), rain shadow areas in the Western and Eastern Ghats and Deccan plateau also experience occasional landslides.

The remaining parts of India, particularly states like Rajasthan, Haryana, Uttar Pradesh, Bihar, West Bengal (except Darjiling), Assam (except Karbi Anglong) and Coastal regions of the southern States are safe as far as landslides are concerned.

Solution: b)

Types of Droughts:

Meteorological Drought: It is a situation when there is a prolonged period of inadequate rainfall marked with mal-distribution of the same over time and space.

Agricultural Drought: It is also known as soil moisture drought, characterized by low soil moisture that is necessary to support the crops, thereby resulting in crop failures. Moreover, if an area has more than 30 per cent of its gross cropped area under irrigation, the area is excluded from the drought-prone category.

Hydrological Drought: It results when the availability of water in different storages and reservoirs like aquifers, lakes, reservoirs, etc. falls below what the precipitation can replenish.

Ecological Drought: When the productivity of a natural ecosystem fails due to shortage of water and as a consequence of ecological distress, damages are induced in the ecosystem.