Daily Quiz: UPSC Prelims Marathon – February 1, 2019

Only 3 is correctly matched.

Aghulas current – east coast of Africa

Benguela Current –west coast of Africa

Humboldt Current – west coast of South America

Statement 1 is incorrect:

Cyclones

• A low pressure area surrounded by high pressure area from all from all the sides along with winds moving from all the sides towards central low
• Cyclones moves in Anti clockwise in N – Hemisphere & in Clockwise direction in S – Hemisphere under the effect of westerlies due to coriolis effect
• No Cyclones at equator as coriolis force is 0 there

An anticycloneis just opposite to a cyclone

• Basically it is a large-scale circulation of winds around a central region of high atmospheric pressure
• Clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere
• Anticyclones are form from air masses, cooling more than their surroundings, which causes the air to contract slightly making the air denser
• Since dense air weighs more, the weight of the atmosphere overlying a location increases, causing increased surface air pressure
• Anticyclones herald fair weather, clearing skies, calm air with high temperature in summers & cold in winters
• Fog can also form overnight within a region of higher pressure

Plate Tectonic Theory:

Conservative Plate Boundaries

• Boundaries where the two plates slide past each other
• A plate is neither created nor destroyed in this case.
• A large amount of stress is released as the plates move against each other.
• Release of stress leads to shallow-focus intense earthquake.

Convergent Plate Boundaries

• Boundaries where the two plates move towards each other.
• Convergence leads to the sinking of the heavier tectonic plate under the lighter one.
• Benioff zone refers to a dipping planar zone of the earthquake that is produced by the interaction of a down-going oceanic crustal plate with a continental plate.
• At the point of subduction the rocks get broken due to compression.

• The Peninsular Plateau is also known as the Deccan Plateau.
• It comprises of most part of southern portion of the nation.
• The plateau ascends 100 meters in the north, ascending further to over 1,000 meters to the south, creating an elevated triangle situated in the well-known downhill-moving triangle of the seashore of the Indian subcontinent.
• The Deccan Plateau stretches over eight states in India and covers a broad variety of environments, encompassing the majority of the Central and South Indian regions. The Deccan Plateau is lying in the middle of three mountain ranges; the Eastern Ghats creates its eastern border and the Western Ghats its western border. Each of the two mountain ranges ascends from their particular adjacent seaward plains and almost joins at the southernmost point of India.
• KarbiAnglong Plateau in Meghalaya is said to be a part of Peninsular Plateau earlier. It is separatedØ from the rest of the peninsular plateau by a fault called Malda Fault.

Some of the major Features of Equatorial Climate:

The most outstanding feature of the equatorial climate is its great uniformity of temperature throughout the year. The mean monthly temperatures are always around 80°F. with very little variation. There is no winter. Cloudiness and heavy precipitation help to moderate the daily temperature, so that even at the equator itself, the climate is not unbearable.

Precipitation is heavy, between 60 inches and 100 inches, and well distributed throughout the year. There is no month without rain, and a distinct dry season like those of the Savanna or the Tropical Monsoon Climates, is absent.

Instead, there are two periods of maximum rainfall, in April and October as shown in Fig. 122 (a) and 122 (b), which occur shortly after the equinoxes. Least rain falls at the June and December solstices.

The double rainfall peaks coinciding with the equinoxes are a characteristic feature of equatorial climates not found in any other type of climate.

High temperature and abundant rainfall in the equatorial regions support a luxuriant type of vegetation-the tropical rain forest. In the Amazon lowlands, the forest is so dense and so complete in its vegetational extravagance that a special term ‘selvas’ is used.

Unlike the temperate regions, the growing season here is all the year round-seeding, flowering, fruiting and decaying do not take place in a seasonal pattern, so some trees may be in flower while others only a few yards away may be bearing fruit. There is neither drought nor cold to check growth in any part of the year.

A tropical marine climate is usually experienced by islands and coastal areas 10° to 20° north or south of the equator.

The ocean is the main influence in creating the tropical marine climate.

There are two main seasons: the wet season and the dry season. The annual rainfall is 1000 to over 1500 mm. The temperature ranges from 20°C to 35°C.

The trade winds blow all year round and are moist, as they pass over warm seas.

All the above statements are correct:

1. The basic cause of Monsoon climates is the difference in the rate of heating and cooling of land and sea. In the summer, when the sun is overhead at the Tropic of Cancer, the great landmasses of northern hemisphere are heated. Central Asia, backed by lofty Himalayan Ranges is more than 15*F. hotter than its normal temperature and a region of intense low pressure is set up. The seas which warm up much slower, remain comparatively cool. At the same time the southern hemisphere experiences winter and a region of high pressure is set up in the continental interior of Australia winds blow outwards as the South East Monsoon, to Java, and after crossing the equator are drawn towards the continental low pressure area reaching the Indian subcontinent as the South West Monsoon. In the Winter the conditions are reversed.
2. The monsoonal vegetation is dependent on the amount of summer rainfall thus the vegetation is most varied ranging from forests to thickests, and from savanna to scrubland.
3. Shifting cultivation is the most primitive form of farming widely practised in the monsoonal type of vegetation. Shifting cultivation is so widely practised amongst indigenous peoples that different local names are used in different countries. For Example: ladang in Malaysia, taungya in Burma, tamrai in Thailand, caingin in Phillipines, humah in Java, Chena I Sri lanka, milpa in Africa and central America.