Test: Geography MCQs (August 2024 Current Affairs) - UPSC MCQ

- Statement 1 is incorrect. The Ashoka Seamount was discovered in 2012, but it was identified using the Russian vessel Akademik Nikolay Strakhov, not the Indian research vessel MGS Sagar.

- Statement 2 is incorrect. The Kalpataru Ridge covers an area of approximately 430 sq km, but it was discovered using the Russian vessel Akademik Nikolay Strakhov, not MGS Sagar.

- Statement 3 is correct. The Chandragupt Ridge extends over 675 sq km and was identified in 2020 by the Indian research vessel MGS Sagar.

Thus, the correct statements are 1 and 3 only. Therefore, the correct answer is Option C: 1 and 3 Only.

Both statements are accurate regarding the formation of pyrocumulonimbus clouds. Statement-I correctly identifies the key factor leading to the formation of these clouds, which is the heat generated from large wildfires or volcanic eruptions. Statement-II further elaborates on this, specifying that pyrocumulonimbus clouds are similar to cumulonimbus clouds but are uniquely driven by the heat generated from such specific sources. Hence, Statement-II provides a more detailed explanation of the formation process outlined in Statement-I. Therefore, option (a) is the correct choice as both statements are correct, and Statement-II effectively explains Statement-I.

Statement-I correctly indicates that the Panama Canal handles approximately 5% of global shipping, not 10% as mentioned in Statement-I. This fact aligns with the information provided in the text about the canal's significance in global trade. Statement-II is inaccurate because the first ship navigated through the Panama Canal on August 15, 1914, and not in 1914 as stated in the statement.

1. Weakening of the Polar Vortex: Disruption of atmospheric waves allowing warm air entry - Correctly matched. The weakening of the polar vortex allows warm air to infiltrate the Antarctic region, contributing to the heatwave.

2. Reduced Antarctic Sea Ice: Increased sunlight reflection leading to cooler temperatures - Incorrectly matched. Reduced sea ice actually decreases sunlight reflection (albedo effect), causing more sunlight to be absorbed by the ocean, leading to higher temperatures.

3. Accelerated Warming in Antarctica: Warming rate nearly double the global average - Correctly matched. Antarctica is warming at a rate of 0.22°C to 0.32°C per decade, which is nearly double the global average.

4. Albedo Effect: Reduced ice cover leading to increased sunlight absorption - Correctly matched. The reduction of ice decreases the Earth's albedo, leading to more sunlight absorption by the ocean, resulting in additional warming.

Thus, three pairs are correctly matched.

Statement 1: Correct. The Panama Canal has indeed been undergoing a prolonged drought that commenced in early 2023. This has significantly reduced the number of ships that can pass through the canal, with numbers dropping to as few as 22 vessels per day in December 2023, compared to the typical 36 to 38 ships.

Statement 2: Correct. The lowered water levels in Lake Gatun have imposed restrictions on the size of vessels that can transit the canal. This is because larger ships require more substantial volumes of water for navigation through the locks, which has become limited due to the drought.

Statement 3: Incorrect. The Panama Canal handles approximately 5% of global shipping, not 15%. While it is still a crucial route for international trade, the percentage is significantly lower than stated.

Thus, the correct answer is Option B: 1 and 2 Only.

1. Lake Gatun - Artificial lake supporting Panama Canal operations: Correct. Lake Gatun is an artificial lake that is crucial for the functioning of the Panama Canal, providing the water necessary to operate the canal's lock system.

2. Kosi River - Tributary of the Ganga River: Correct. The Kosi River, known as the "Sorrow of Bihar," flows through Nepal and India and merges with the Ganga River near Kursela in Katihar district, Bihar.

3. Mechi River - Originates in the Mahabharat range of hills in Nepal: Correct. The Mechi River is a trans-boundary river, originating in the inner valley of the Himalayas in the Mahabharat range of hills in Nepal, and flows through Bihar, India.

4. Panama Canal - Connects the Indian Ocean to the Atlantic Ocean: Incorrect. The Panama Canal connects the Atlantic Ocean to the Pacific Ocean, not the Indian Ocean.

Thus, three pairs are correctly matched.

The melting of polar ice caps leads to water flowing towards the equator, which increases the Earth's oblateness and moment of inertia. This phenomenon results in a slowing down of the Earth's rotation, as mass distribution near the equator rises, in accordance with the conservation of angular momentum principle. The change in rotational dynamics due to melting ice caps showcases the significant impact of climate change on Earth's fundamental processes.

The primary factor contributing to the heatwave in Antarctica is the weakening of the Polar Vortex, which is a band of cold air and low-pressure systems that typically circulate around the Earth's poles in the stratosphere. This weakening allows warm air to infiltrate the region, leading to elevated temperatures.

Pyrocumulonimbus clouds are special thunderclouds formed due to intense heat generated from large wildfires or volcanic eruptions. These clouds, driven by the heat from the Earth's surface, appear darker than typical clouds due to the presence of smoke and ash. They have the potential to trap aerosol pollutants in the stratosphere and can even ignite new fires through lightning strikes.

Both statements are individually correct based on the provided information. Statement-I discusses the impact of polar ice melting on Earth's rotation, while Statement-II addresses the deep-winter heatwaves in Antarctica and their consequences. However, these statements do not directly relate to each other or explain one another. The information provided in the statements, while accurate, covers different aspects of climate change effects and does not establish a clear explanatory link between them.

The prolonged drought affecting the Panama Canal operations has imposed restrictions on the size of vessels that can transit the canal. Lowered water levels mean that larger ships face a greater risk of grounding in shallower waters, impacting the smooth passage of vessels through the canal.

Statement 1: The melting of polar ice sheets indeed leads to water flowing towards the equator. This redistribution of mass increases the Earth's oblateness (flattening at the poles) and moment of inertia (resistance to rotational change). This change in mass distribution causes the Earth's rotational speed to decrease to conserve angular momentum. Therefore, statement 1 is correct.

Statement 2: As Earth's rotation slows down, the discrepancy between atomic time (measured by highly precise atomic clocks) and solar time (based on the Earth's rotation) increases. To maintain synchronization, additional leap seconds may be required. Systems relying on precise timekeeping, such as GPS and network timestamps, could be affected by these adjustments. Hence, statement 2 is correct.

Statement 3: Melting polar ice affects the Earth's axis of rotation, leading to slight but measurable shifts. This phenomenon, known as the Chandler wobble, can influence rotational timing and stability. Therefore, statement 3 is incorrect.

Thus, the correct statements are 1 and 2.

Answer: Option B: 1 and 2 Only

Statement 1: Correct. The primary factor contributing to the heatwave in Antarctica is indeed the weakening of the polar vortex. The polar vortex is a band of cold air and low-pressure systems that circulate around the Earth's poles in the stratosphere. When the vortex weakens, it allows warm air to infiltrate the region, leading to higher temperatures.

Statement 2: Correct. Reduced Antarctic sea ice has contributed to the heatwave by absorbing more sunlight. Sea ice typically reflects sunlight back into space, helping to keep temperatures low. With less sea ice, more sunlight is absorbed by the ocean, leading to higher temperatures.

Statement 3: Incorrect. While the statement correctly mentions that temperatures have spiked significantly in East Antarctica, the heatwave is not necessarily confined to this region alone. The description provided does not limit the heatwave's impact to East Antarctica exclusively.

Therefore, the correct answer is Option B: 1 and 2 Only.

Statement-I correctly highlights the ongoing severe winter heatwave in Antarctica, emphasizing the abnormal temperature spikes. Statement-II accurately explains the primary reason behind this heatwave, which is the weakening of the polar vortex, allowing warm air intrusion due to disruptions caused by atmospheric waves. The weakening of the polar vortex has indeed led to the unusual warmth in Antarctica, making both statements correct, with Statement-II providing a logical explanation for the situation described in Statement-I.

1. Raman Ridge - Discovered by the Indian research vessel Sagar Kanya (Incorrect)
Raman Ridge was discovered by a US oil vessel in 1951 and accepted in 1992.

2. Panikkar Seamount - Named after physicist Sir CV Raman (Incorrect)
Panikkar Seamount is named after renowned oceanographer NK Panikkar.

3. DN Wadia Guyot - Named after geologist DN Wadia (Correct)
DN Wadia Guyot was named in 1993 after geologist DN Wadia and was discovered by the Indian research vessel Sagar Kanya.

4. Ashoka Seamount - Identified using Russian vessel Akademik Nikolay Strakhov (Correct)
Ashoka Seamount was discovered in 2012, spanning approximately 180 sq km, and identified using the Russian vessel Akademik Nikolay Strakhov.

Only pairs 3 and 4 are correctly matched.