QUIZ – 2020: INSIGHTS STATIC , 26 July 2021 – Geography – INSIGHTSIAS

Solution: a)

What are meteor showers?

• Meteors are bits of rock and ice that are ejected from comets as they manoeuvre around their orbits around the sun.
• Meteor showers are witnessed when Earth passes through the trail of debris left behind by a comet or an asteroid.

Why is the Geminid meteor shower considered to be the best of the year?

The Geminids meteor showers are unique because their origin does not lie in a comet, but what is believed to be an asteroid or an extinct comet. The Geminids emerge from 3200 Phaethon, which meteor scientists consider to be an asteroid.

Solution: b)

Scientists of the Wadia Institute of Himalayan Geology (WIHG) conducted a study on Geothermal springs in Himalayas.

Key observations and findings:

1. Geothermal springs cover about 10,000 square kms in the Garhwal region of the Himalayas in Uttarakhand.
2. The Himalayas host hundreds of geothermal springs and they release a huge amount of carbon dioxide in the atmosphere.
3. CO2 in these thermal springs are sourced from metamorphic decarbonation of carbonate rocks present deep in the Himalayan core along with magmatism and oxidation of graphite.
4. Most of the geothermal water is dominated by evaporation followed by weathering of silicate rocks.

What are hot/geothermal springs?

A hot spring is a spring produced by the emergence of geothermally heated groundwater that rises from the Earth’s crust.

Solution: d)

Indonesia is home to many active volcanoes, due to its position on the “Ring of Fire”, or the Circum-Pacific Belt, which is an area along the Pacific Ocean characterised by active volcanoes and frequent earthquakes.

• The Ring of Fire is home to about 75 per cent of the world’s volcanoes and about 90 per cent of its earthquakes.

Why do volcanoes erupt?

• A volcano can be active, dormant or extinct.
• An eruption takes place when magma (a thick flowing substance), formed when the earth’s mantle melts, rises to the surface.
• Because magma is lighter than solid rock, it is able to rise through vents and fissures on the surface of the earth. After it has erupted, it is called lava.

Not all volcanic eruptions are explosive, since explosivity depends on the composition of the magma.

Solution: c)

All waters in nature, whether rain water or ocean water, contain dissolved mineral salts.  Salinity is the term used to define the total content of dissolved salts in sea water.

Factors affecting ocean salinity are mentioned below:

• The salinity of water in the surface layer of oceans depend mainly on evaporation and precipitation.
• Surface salinity is greatly influenced in coastal regions by the fresh water flow from rivers, and in polar regions by the processes of freezing and thawing of ice.
• Wind, also influences salinity of an area by transferring water to other areas.
• The ocean currents contribute to the salinity variations. Salinity, temperature and density of water are interrelated. Hence, any change in the temperature or density influences the salinity of water in an area.

Solution: d)

• The lofty Himalayas in the north along with its extensions act as an effective climatic divide. The towering mountain chain provides an invincible shield to protect the subcontinent from the cold northern winds.
• These cold and chilly winds originate near the Arctic circle and blow across central and eastern Asia. The Himalayas also trap the monsoon winds, forcing them to shed their moisture within the subcontinent.
• As compared to the landmass, water heats up or cools down slowly. This differential heating of land and sea creates different air pressure zones in different seasons in and around the Indian subcontinent. Difference in air pressure causes reversal in the direction of monsoon winds.