Daily Static Quiz (Geography) December 11, 2025

Daily Static Quiz (Geography) December 11, 2025

Question 1
Monsoon winds approaching the western coast of India experience a significant increase in moisture content as they travel across the Arabian Sea. However, upon crossing the Western Ghats, the regions lying on the eastern slopes receive considerably less rainfall than their western counterparts. Which of the following geomorphological and atmospheric processes best explains this phenomenon?

(a) The reversal of Coriolis force direction causes eastward deflection of winds at higher latitudes

(b) Orographic lifting on the windward slopes causes cooling, condensation, and precipitation, while adiabatic warming on the leeward slopes reduces moisture capacity

(c) The rain shadow effect is created due to the formation of katabatic winds on the western slopes of the Ghats

(d) The eastern slopes face the Arabian Sea monsoon, which carries moisture-depleted air masses from the equatorial regions

Question 2
The Indus, Sutlej, and Brahmaputra rivers maintain their original courses and have carved through the Himalayan mountain ranges despite significant tectonic uplift occurring during their evolution. The geological concept that best describes this river behavior is:

(a) Consequent drainage system where rivers flow from source to sea following topographic slopes

(b) Antecedent river system where rivers pre-date the mountain uplift and maintain their courses through continuous downcutting

(c) Superimposed drainage system where river patterns inherited from earlier geological formations overlie current tectonic structures

(d) Subsequent drainage system where rivers develop after uplift and exploit structural weaknesses in rocks

Question 3
Recent geological surveys have identified extensive karst formations in the Vindhya region and parts of the eastern Himalayas, characterized by underground drainage, sinkholes, and cave systems. Which combination of conditions is absolutely essential for the full development of such karst topography?

(a) Porous and fractured soluble limestone positioned above the water table with adequate rainfall

(b) Dense, non-fractured limestone with poor permeability and high water table elevation

(c) Granitic rock formations with high chemical weathering rates in humid tropical climates

(d) Shale and sandstone alternations in tectonically active zones with frequent earthquakes

Question 4
The Hadley cell circulation pattern plays a crucial role in determining global climate distribution. Consider the following statements regarding its mechanism and effects:

1. Air rises at the equator due to intense solar heating, becomes saturated with moisture, and triggers heavy precipitation in the Intertropical Convergence Zone (ITCZ)
2. The descending branch of the Hadley cell occurs around 30° north and south latitude, creating high-pressure zones that suppress rainfall
3. The location of major world deserts corresponds with the sinking branches of Hadley cells where moisture-depleted air descends

Which of the statements given above are correct?

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

Question 5
The Indian Ocean Dipole (IOD) and El Niño-Southern Oscillation (ENSO) represent critical oceanic-atmospheric interaction patterns. During a positive IOD phase, which of the following conditions typically occurs in the Indian Ocean region?

(a) Greater-than-average sea-surface temperatures in the western Indian Ocean with increased precipitation, while eastern waters cool, potentially causing droughts in adjacent landmasses

(b) Uniform warming across the entire Indian Ocean basin with enhanced monsoon rainfall throughout South Asia and Southeast Asia

(c) Cooling of western Indian Ocean waters coinciding with warming in the eastern regions, strengthening the southwest monsoon systems

(d) Formation of high-pressure cells over the Arabian Sea that deflect monsoon winds northeastward along the Indian coast

Question 6
The syntaxial bending observed in the Himalayan mountain range, particularly visible at the northwestern and northeastern extremities (Western and Eastern Syntaxial Bends), resulted from a specific tectonic process following the collision of the Indian and Asian plates. The primary cause of this bending pattern was:

(a) Gravitational collapse of the newly formed mountain belt along pre-existing fault lines

(b) Rotational movement of the Indian Plate combined with its reduced northward drift velocity after collision

(c) Differential erosion rates creating structural weakness zones in the mountain axis

(d) Transform fault movements accommodating the lateral escape of crustal material eastward and westward

Question 7
Fjords represent distinctive glacial landforms characterized by narrow, deep inlets with steep cliffs. The overdeepened basins found in fjords, particularly those exceeding 1,000 meters in depth, are direct results of which geomorphological process?

(a) Repeated tidal erosion during periods of high sea level stands in the Quaternary era

(b) Intense chemical weathering of carbonate rocks by acidic glacial meltwater

(c) Glacial erosion through ice segregation and abrasion, creating U-shaped valleys subsequently flooded by rising sea levels

(d) Submarine canyon formation through turbidity currents and submarine slumping along continental margins

Question 8
Laterite soils, widely distributed across the Western Ghats, parts of Odisha, Assam, and the Deccan Plateau, form through a specific weathering process. Under which climatic and hydrological conditions is laterization most intensively developed?

(a) High altitude regions with glacial weathering and periglacial processes dominating soil formation

(b) High temperature and heavy rainfall with alternate wet and dry periods causing intense leaching of lime and silica while iron and aluminum oxides accumulate

(c) Arid zones with minimal rainfall where mechanical weathering produces fragmented rock material

(d) Temperate maritime climates with moderate rainfall and stable soil moisture conditions throughout the year

Question 9
The Walker Cell circulation pattern represents a crucial zonal (east-west) circulation system in the equatorial Indian and Pacific Oceans. During normal conditions, this circulation pattern is characterized by:

(a) Rising air over the eastern Pacific and sinking over the western Pacific, with surface winds flowing eastward (easterlies)

(b) Rising air over the western Indian and Pacific Oceans with sinking over the eastern regions, coupled with surface winds flowing westward (westerlies)

(c) Rising air over the maritime continent and western Pacific with sinking over the eastern Pacific, accompanied by trade wind patterns flowing from east to west

(d) Uniform air pressure distribution across the equatorial zone with negligible vertical motion and wind circulation systems

Question 10
The Somali Current (also known as Findlater Current) exhibits a remarkable directional reversal every six months in response to monsoon wind pattern changes. The critical factor that explains the weakness of monsoon winds in India during exceptional years relates to a reversal of the:

(a) Pressure gradient between the Indian Ocean and the Arabian Sea, transforming the low-pressure area along Somalia’s eastern coast into a high-pressure region

(b) Trade wind direction in the Southern Hemisphere, causing the Coriolis force to lose its deflecting capacity

(c) Subtropical jet stream position, shifting from the Himalayas to the equatorial regions

(d) ITCZ location, moving permanently from the Indian subcontinent to the Pacific Ocean basin

Answer Key with Explanations

Answer 1: (b)

Explanation:

The phenomenon described represents a classic example of orographic rainfall and the rain shadow effect. When moisture-laden southwest monsoon winds encounter the Western Ghats (windward slopes), they are forced to ascend due to the mountainous terrain. This orographic lifting causes the air to cool adiabatically at the Dry Adiabatic Lapse Rate (DALR) initially, and when saturation occurs, at the Saturated Adiabatic Lapse Rate (SALR). This cooling triggers condensation and precipitation on the western (windward) slopes.

As the now moisture-depleted air descends on the eastern (leeward) slopes, it undergoes adiabatic warming. This warming increases the air’s capacity to hold moisture, reducing relative humidity and creating dry conditions. This creates the rain shadow effect, which explains why regions like Pune (on the leeward side) receive significantly less rainfall than nearby regions on the windward side like Mangalore.

Option (a) is incorrect because Coriolis force deflection operates primarily on a larger scale and does not create the windward-leeward differential. Option (c) confuses katabatic winds with orographic effects. Option (d) is geographically inaccurate as the eastern slopes receive monsoon winds that have already lost their moisture.

—

Answer 2: (b)

Explanation:

Antecedent rivers are streams that originated before the major uplift of the landmass they currently flow through, and they have maintained their original courses by continuously eroding downward (downcutting) through the rising terrain. The Indus, Sutlej, Ganga, and Brahmaputra are prime examples of antecedent rivers. These rivers existed on a stable landscape before the Himalayan uplift occurred. As the Himalayas rose due to the ongoing collision between the Indian and Eurasian plates (approximately 70 million years ago), these rivers maintained their courses by cutting deeper into the rising mountains, creating gorges and deep valleys.

This process demonstrates the principle of dynamic equilibrium, where the river’s capacity for vertical erosion exceeds the rate of tectonic uplift in localized areas. The formation of transverse gorges across mountain ranges is a defining characteristic of antecedent drainage systems.

Option (a) refers to consequent drainage, which follows topographic slopes but doesn’t explain trans-mountain cutting. Option (c) (superimposed drainage) involves patterns inherited from earlier formations, which is not the primary characteristic here. Option (d) (subsequent drainage) develops after uplift along structural weaknesses, which is not applicable to these major rivers.

—

Answer 3: (a)

Explanation:

Karst topography develops exclusively in soluble rock terrains, primarily limestone, dolomite, and gypsum. However, not all limestone regions develop karst features equally. Several essential conditions must be simultaneously present:

1. Soluble Rock Material: The rocks must be primarily composed of calcium carbonate (limestone) or magnesium carbonate (dolomite). These rocks are vulnerable to chemical dissolution by slightly acidic rainwater (containing dissolved CO₂).

2. High Porosity and Fracturing: The limestone must be porous and extensively fractured (jointed) to allow percolation of water into the subsurface. Dense, non-fractured limestone restricts subsurface drainage.

3. Position Above Water Table: The limestone should be positioned above the water table so that water can percolate through it. If the water table is too high, the system becomes waterlogged and underground drainage cannot develop properly.

4. Adequate Rainfall: Sufficient precipitation is necessary to provide the acidic water capable of dissolving limestone. Arid regions with minimal rainfall cannot develop extensive karst features despite having limestone.

Option (b) is incorrect as it stipulates non-fractured limestone and high water table—conditions that inhibit karst development. Options (c) and (d) reference unsuitable rock types and processes.

—

Answer 4: (d)

Explanation:

The Hadley cell circulation represents one of Earth’s three primary atmospheric circulation cells. A comprehensive understanding of its mechanism is essential for UPSC prelims:

Statement 1 – CORRECT: At the equator, intense solar radiation heats the surface, causing air to rise. This rising air carries significant moisture through convection. As the air rises and expands adiabatically, it cools. When cooling reaches the dew point, condensation occurs, releasing latent heat and causing heavy precipitation. This rising motion and precipitation occur within the ITCZ, a belt of intense rain-producing thunderstorms around the equator.

Statement 2 – CORRECT: The rising air at the equator moves poleward at upper atmospheric levels (around 12-15 km altitude). As it moves toward higher latitudes (approximately 30° N and S), it cools further and becomes denser. This air descends (sinks) at subtropical latitudes. As air descends, it undergoes adiabatic warming, which increases its moisture-holding capacity. This creates high-pressure zones where rainfall is suppressed, resulting in the characteristic clear, stable weather patterns of subtropical regions.

Statement 3 – CORRECT: The world’s major deserts—the Sahara, Arabian, Atacama, Australian, and Kalahari—are all positioned between 15° and 35° latitude, corresponding precisely with the sinking branches of Hadley cells. The descending, warming air cannot support condensation, creating persistent dry conditions.

All three statements are factually accurate and logically connected.

—

Answer 5: (a)

Explanation:

The Indian Ocean Dipole (IOD) represents a coupled ocean-atmosphere interaction system specific to the Indian Ocean, operating independently of ENSO but often interacting with it. The IOD oscillates between three phases: positive, neutral, and negative.

During a Positive IOD Phase:

– Western Indian Ocean: Sea-surface temperatures (SSTs) become anomalously warm, exceeding the long-term average. This warming enhances evaporation and atmospheric convection, leading to increased precipitation over regions like East Africa, the Middle East, and sometimes parts of South Asia.

– Eastern Indian Ocean: Water temperatures become anomalously cool, suppressing convection and reducing rainfall. This cooling, combined with the pressure gradient associated with warm western waters, can contribute to droughts in adjacent landmasses like Indonesia and Australia.

– Monsoon Enhancement: A positive IOD phase typically strengthens the southwest monsoon over the Indian subcontinent, increasing rainfall, while simultaneously weakening monsoons in Southeast Asia.

Option (b) is incorrect because the IOD does not produce uniform basin-wide warming. Option (c) describes cooling in the west and warming in the east—the negative IOD phase, not positive. Option (d) misattributes pressure cell formation to the IOD mechanism.

—

Answer 6: (b)

Explanation:

The syntaxial bending (also called syntaxes or syntaxial bends) refers to sharp, pronounced bends in the Himalayan mountain axis at the northwestern extremity (Nanga Parbat syntaxis) and northeastern extremity (Namcha Barwa syntaxis). These features result from specific tectonic conditions:

Primary Cause – Rotational Movement:

Following the collision of the Indian Plate with the Eurasian Plate approximately 50 million years ago, the Indian Plate’s northward drift was significantly retarded. However, rather than completely halting, the plate began rotating clockwise (when viewed from above). This rotation, combined with the plate’s reduced but continued northward movement, caused intense compressive stress to be redirected, creating sharp bends in the mountain chain.

Mechanism:

The rotation creates a structural geometry where the initially linear mountain belt becomes bent. At the syntaxial bends, the mountain axis curves sharply. The Nanga Parbat massif (Western Syntaxial Bend) represents an area of intense uplift and exhumation, while the Namcha Barwa region (Eastern Syntaxial Bend) shows similar characteristics. The rotation of the Indian Plate is facilitated by the existence of the Arabian Sea to the south and the overall geometry of the plate margin.

Geological Evidence:

Radiometric dating of rocks and structural geological analysis reveal that the rotation initiated after the main collision phase, indicating that plate kinematics—specifically rotational movement—was the primary driver.

Option (a) incorrectly attributes the bending to gravitational collapse. Option (c) oversimplifies the process by focusing only on erosion. Option (d) confuses the mechanism with lateral extrusion tectonics seen in Southeast Asia (e.g., the Sunda Arc).

—

Answer 7: (c)

Explanation:

Fjords represent the world’s most dramatic examples of glacial erosion and landscape modification. The formation process involves several interconnected mechanisms:

Formation Sequence:

1. Pre-glacial Valley: Before glaciation, a typical river valley has a V-shaped cross-section formed by fluvial erosion.

2. Glacial Deepening: During glaciation, a glacier occupies this valley. Unlike rivers that erode primarily through hydraulic action and abrasion along the valley floor, glaciers employ multiple erosion mechanisms:
– Ice Segregation: Water in the bedrock freezes and expands, fragmenting rock material.
– Plucking: Glaciers quarry large blocks from the bedrock and incorporate them into the ice.
– Abrasion: Rock fragments embedded in glacial ice scrape and polish the bedrock.

3. U-shaped Valley Creation: These processes, acting simultaneously across the entire valley width and considerable depth, transform the V-shaped valley into a U-shaped glacial trough. Importantly, glaciers erode the valley floor far more vigorously than river systems do.

4. Overdeepening: Glacial erosion can cut the valley floor below current sea level, creating basins 1,000+ meters deep (e.g., Sognefjord, Norway—approximately 1,300 meters below sea level).

5. Marine Inundation: When glaciers retreat, two processes occur:
– Sea level rises due to meltwater from global ice sheets.
– Isostatic Rebound: The land, no longer burdened by glacial ice, begins rising. However, in most fjord regions, sea level rise outpaces crustal rebound, and the previously ice-filled valley floods with seawater, creating a fjord.

Threshold Formation:

Many fjords feature a rocky threshold (sill) at their mouth. This forms where the glacier’s erosion rate decreased as the ice terminus entered the ocean and became partially buoyant, reducing its downward force.

Option (a) incorrectly attributes formation to tidal action. Option (b) confuses chemical weathering processes with glacial erosion. Option (d) describes submarine processes unrelated to fjord formation.

—

Answer 8: (b)

Explanation:

Laterite soils represent the end product of intensive chemical weathering in tropical and subtropical climates. The laterization process is fundamentally different from other weathering regimes:

Essential Climatic Conditions:

1. High Temperature: Tropical and subtropical temperatures accelerate chemical reaction rates exponentially (following the Van ‘t Hoff principle—a 10°C increase approximately doubles reaction rates). High temperatures also increase evaporation rates, concentrating weathering solutions.

2. High Rainfall: Copious precipitation provides water necessary for chemical weathering reactions. Rainwater, containing dissolved CO₂, forms carbonic acid, which dissolves minerals.

3. Alternate Wet-Dry Cycles: This is crucial and often overlooked. During wet periods, water percolates through the soil profile, leaching soluble minerals (especially silica and lime/calcium). During dry periods, upward capillary movement concentrates sesquioxides (iron and aluminum oxides) in upper horizons. The cyclical repetition intensifies this differentiation.

Weathering Process:

– Feldspar minerals in the parent rock are attacked by carbonic acid and hydrolyzed.
– Silica is highly soluble in acidic, waterlogged soil and is leached downward in solution.
– Iron and aluminum oxides are relatively insoluble and remain concentrated in the upper profile.
– The result is a reddish-brown soil rich in iron oxide (Fe₂O₃) and aluminum oxide (Al₂O₃) but depleted in silica, lime, and organic matter.

Distribution in India:

Laterite soils are extensively developed in the Western Ghats (summits at 1,000-1,500 m elevation), parts of Karnataka, Maharashtra, Chhattisgarh, Odisha, Assam, and the Deccan Plateau—all regions experiencing the requisite climatic conditions.

Option (a) describes glacial weathering—not applicable to laterite zones. Option (c) describes mechanical weathering in arid zones, which produces entirely different soil types. Option (d) describes temperate maritime conditions where podzolic soils (not laterites) develop.

—

Answer 9: (c)

Explanation:

The Walker Cell (also known as the Walker Circulation) represents an east-west (zonal) atmospheric circulation pattern discovered by Sir Gilbert Walker in his studies of the Southern Oscillation phenomenon.

Normal Walker Cell Circulation:

Rising Air (Convective Activity):
– Air rises over the maritime continent (Indonesia, Philippines) and western Pacific Ocean regions.
– This region experiences the warmest sea-surface temperatures and the strongest atmospheric convection.
– Heavy precipitation occurs over these areas.

Upper-level Divergence:
– Rising air moves eastward at upper tropospheric levels (approximately 10-15 km altitude).

Sinking Air:
– Air descends over the eastern Pacific Ocean (near Peru and Ecuador).
– This sinking motion creates the South Pacific high-pressure anticyclone.
– The descending air is dry, creating conditions unfavorable for precipitation.

Surface Wind Pattern:
– The pressure gradient between high pressure in the east and low pressure in the west drives surface winds from east to west (the easterly trade winds).
– These surface winds complete the circulation cell.

Relationship to ENSO:

During El Niño events, the Walker Cell weakens dramatically. The eastern Pacific warms anomalously, reducing the east-west pressure gradient, weakening trade winds, and disrupting the typical circulation pattern.

Option (a) reverses the circulation—describing rising air in the wrong location. Option (b) incorrectly describes westerlies at the surface (westerlies exist in mid-latitudes, not the tropics). Option (d) is incorrect because the Walker Cell is a fundamental feature of tropical circulation, not negligible.

—

Answer 10: (a)

Explanation:

The Somali Current (Findlater Current) is a monsoon-driven ocean current flowing along the eastern African coast. Its behavior is intimately linked to monsoon wind patterns and underlying pressure systems.

Normal Somali Current Behavior:

During Southwest Monsoon (June-September):
– Intense low-pressure systems develop over the Tibetan Plateau and the Indian interior.
– Strong pressure gradients drive forceful southwest monsoon winds toward the Indian subcontinent.
– These winds extend into the Indian Ocean, driving the Somali Current northwestward (from Somalia toward the Arabian Sea).
– The Somali Current becomes a powerful western boundary current, comparable in intensity to the Gulf Stream.
– This current significantly enhances moisture transport to the Indian subcontinent, strengthening the monsoon.

During Northeast Monsoon (October-March):
– The Somali Current reverses direction, flowing southwestward.

Exceptional Weak Monsoon Years:

Occasionally (roughly every 6-7 years), the Somali Current weakens dramatically, and monsoon rains fail over the Indian subcontinent. The primary cause is:

– A critical pressure reversal occurs: the typical low-pressure anomaly along Somalia’s eastern coast becomes a high-pressure anomaly.
– This pressure reversal indicates anomalously warm sea-surface temperatures in the western Indian Ocean (characteristic of positive IOD events or specific ENSO configurations).
– The reversed pressure gradient weakens the monsoon wind system.
– Consequently, the Somali Current weakens or reverses prematurely.
– The reduced current strength means less moisture advection toward India, resulting in below-normal monsoon rainfall.

This pressure reversal mechanism is a primary indicator used by meteorologists to forecast monsoon strength and intensity for the upcoming season.

Option (b) incorrectly references hemispheric Coriolis force properties. Option (c) misidentifies the causal mechanism. Option (d) incorrectly attributes the effect to ITCZ migration alone, whereas pressure systems in the Arabian Sea are the direct cause.

Daily Static Quiz