Insights Static Quiz -231, 2019–Geography

Solution: d)

Continental Shelf is the submerged edge of a continent which is a gently sloping plain that extends into the Ocean. The typical gradient is less than 1°. The average width of continental shelves is about 80 km. The largest continental shelf is the Siberian Shelf in the Arctic Ocean, which stretches to 1,500 kilometers in width. Because of the gentle slope, the continental shelf is influenced by the changes in the sea level.

The shelf is formed mainly due to

• Rise in sea level
• Submergence of a part of a continent
• Sedimentary deposits brought down by rivers

Solution: d)

A tsunami is a large ocean wave that is caused by sudden motion on the ocean floor. This sudden motion could be an earthquake, a powerful volcanic eruption, or an underwater landslide. The impact of a large meteorite could also cause a tsunami. Tsunamis travel across the open ocean at great speeds and build into large deadly waves in the shallow water of a shoreline.

Solution: b)

PM has announced new names for 3 islands in Andaman & Nicobar, honouring Netaji Subhas Chandra Bose and his Indian National Army. Ross Island is now Netaji Subhas Chandra Bose Dweep, Neil Island is Shaheed Dweep, Havelock Island is Swaraj Dweep. All 3 are in South Andaman district.

Solution: a)

Temperature inversion is a phenomenon where a layer of warm air is formed on top of a layer of cold air, unlike in normal atmospheric conditions.

One of the most noticeable effects of a temperature inversion is on air quality. During the winter, temperature inversions are stronger and more common. This is generally when air quality suffers most as a result of temperature inversions. The warm air on top of the cool air acts as a lid, trapping pollution such as car emissions and smoke from fireplaces close to the ground. This results in hazy skies and poor air quality.

Temperature inversions are also responsible for certain cloud formations. When clouds form just below the inversion in the sky, they spread out and have a very flat smooth appearance. These clouds are often seen over cool ocean waters where temperature inversions are common.

Temperature inversions can keep thunderstorms from forming. Most thunderstorms happen during hot and humid weather at the surface, but they are unable to strengthen if the tops of the storms are unable to rise and retain their heat energy. When the typical temperatures are applied to the atmosphere with cooler temperatures at higher altitudes, it actually forms an unstable air layer that is ideal for the formation of thunderstorms.

Solution: a)

Damodar occupies the eastern margins of the Chotanagpur Plateau where it flows through a rift valley and finally joins the Hugli. Barakar is its main tributary.

The Sharda River or Mahakali River is also called Kali Gad or Kali Ganga in Uttarakhand where the river demarcates Nepal’s western border with India.