[Mission 2024] STATIC QUIZ, 19 August 2023 – Geography

Solution: d)

The recent earthquakes in different parts of India, albeit of small magnitudes, have occurred due to foreshocks and swarms, a top official of the Geological Survey of India (GSI) said.

Foreshocks — mild tremor preceding earthquakes — or swarm activities — series of earthquakes — indicate release of tectonic stress and strain during the continuous deformation process, and a detailed study of these jolts could help predict if a significant seismic event is in store.

These minor earthquakes are mainly clustered in the north-eastern and north-western Himalayan region, around the Delhi-National Capital Territory (NCT), western Gujarat and Western Maharashtra areas which have been demarcated as seismic zones IV and V.

Solution: a)

The Big Bang Theory considers the following stages in the development of the universe.

(i) In the beginning, all matter forming the universe existed in one place in the form of a “tiny ball” (singular atom) with an unimaginably small volume, infinite temperature and infinite density.

(ii) At the Big Bang the “tiny ball” exploded violently. This led to a huge expansion. It is now generally accepted that the event of big bang took place 13.7 billion years before the present. The expansion continues even to the present day. As it grew, some energy was converted into matter. There was particularly rapid expansion within fractions of a second after the bang. Thereafter, the expansion has slowed down. Within first three minutes from the Big Bang event, the first atom began to form.

(iii) Within 300,000 years from the Big Bang, temperature dropped to 4,500K (Kelvin) and gave rise to atomic matter. The universe became transparent.

Solution: c)

Plate margins witness several plate collisions, sliding, transformation etc that result into volcanism or earthquakes.

Most of them are found in the Ring of Fire.

Some earthquakes also occur within the plates but not as frequently as on the plate margins.

Solution: b)

Statement 2 is incorrect.

Earth quakes are usually associated with volcanoes, since both are related to plate movements.

Volcanoes can also happen with ocean-ocean crust collision. Best example is South East Asian Archipelago.

Volcanoes are one of the best sources of sulphur, which is not abundant on other continental landforms.

Solution: c)

The troposphere is thicker at the equator than at the poles because the equator is warmer. The convection currents of air expand the thickness of the troposphere (atmosphere).

Thus the simple reason is thermal expansion of the atmosphere at the equator and thermal contraction near the poles.

Also, the rotation of the earth causes centrifugal force which is strongest near the equator and pushes the atmosphere to greater heights.

The thickness of the troposphere also varies with season. The troposphere is thicker in the summer and thinner in the winter all around the planet.