UPSC Static Quiz – Geography : 17 September 2024

Solution: c)

Landforms of First Order are massive, large-scale features shaped by internal tectonic forces. These include continents such as Eurasia, Africa, Americas, and ocean basins like the Pacific and Atlantic Oceans. These primary landforms were formed through processes such as folding (anticlines and synclines) and other tectonic movements. Over time, they came to be identified as continents and oceanic features. Their scale and origin distinguish them from smaller landforms shaped by external forces, such as erosion or deposition, which are considered landforms of the second and third orders.

Solution: b)

One of the key pieces of evidence supporting Alfred Wegener’s Continental Drift Theory is the striking similarity in the coastlines of South America and Africa. The coastlines fit together like pieces of a puzzle, suggesting that these continents were once connected. Other pieces of evidence include fossil correlations and the distribution of mountain ranges, but the mirror image of these coastlines remains one of the most iconic and observable pieces of evidence. Volcanic activity and ocean floor spreading are related to plate tectonics, which built on the continental drift concept.

Solution: d)

None of the statements are correct based on Alfred Wegener’s theory:

Statement 1 is incorrect because Wegener suggested that centrifugal force increases towards the equator, not the poles. This force, along with Earth’s equatorial bulge, contributed to the “pole-fleeing” effect, pushing continents away from the poles towards the equator.

Statement 2 is incorrect because Wegener argued that tidal forces acted from east to west (not west to east) due to Earth’s westward tidal drag, influencing the westward drift of the continents.

Statement 3 is incorrect because Wegener did not attribute the drift to Earth’s gravitational pull causing eastward movement. Instead, he suggested forces like gravity, buoyancy, centrifugal force, and tidal currents as drivers of the continental drift.

Solution: c)

Statement 1 is correct because the Mid-Atlantic Ridge is the longest continuous mountain chain on Earth, stretching over 84,000 km.

Statement 4 is correct because studies of Earth’s magnetism, specifically magnetic striping on the ocean floor, have provided crucial evidence for the hypothesis of sea-floor spreading.

Statement 2 is incorrect because deep-sea trenches form at convergent plate boundaries, not divergent ones. Divergent boundaries, such as mid-ocean ridges, are where new ocean floor is created.

Statement 3 is incorrect because sea-floor spreading creates new crust at mid-ocean ridges, but it is the process of subduction at convergent boundaries that leads to the recycling of oceanic crust into the mantle.

Solution: a)

Statement 1 is correct because the lithosphere, which consists of Earth’s outer rigid shell, is divided into several tectonic plates. These plates move due to mantle convection, where heat from Earth’s interior causes the movement of material in the mantle.

Statement 2 is incorrect because earthquakes and volcanic activity primarily occur along the boundaries of tectonic plates, not within their interiors. These geological events are common at convergent, divergent, and transform boundaries.

Statement 3 is incorrect because divergent boundaries are where tectonic plates move away from each other, not towards each other. When plates move towards each other, they form convergent boundaries, which can lead to mountain-building.