Day-581 | Daily MCQs | UPSC Prelims | GEOGRAPHY

Answer: A
Explanation: Both the statements are correct and Statement-II is correct explanation of Statement-I.
What are Eclipses?
• Eclipses are astronomical events that occur when the sun, moon, and Earth align in specific ways.
• There are two primary types of eclipses: solar and lunar.
• A solar eclipse happens when the moon comes between the sun and Earth during a new moon, blocking out the sun’s light.
• Conversely, a lunar eclipse occurs when the Earth is positioned between the sun and the moon during a full moon, casting a shadow on the moon.
Why is there no eclipse every full and new moon?
• Moon’s Path: The moon orbits around Earth, completing one orbit roughly every month.
• Ecliptic Plane: In an ideal scenario, if the moon’s orbit matched Earth’s orbital plane, called the ecliptic, we would witness a solar eclipse during every new moon and a lunar eclipse during every full moon.
• Moon’s Inclination: However, the moon’s orbit is inclined at an angle of about 5 degrees to Earth’s orbital plane, causing irregular eclipse patterns.
Role of Lunar Nodes
• Lunar Nodes: The moon’s orbit intersects Earth’s orbital plane at specific points known as nodes, categorized as ascending or descending nodes depending on the moon’s orbital direction.
• Eclipse Occurrence: Eclipses happen when a full or new moon closely aligns with one of these nodes, ensuring the sun, moon, and Earth are in alignment.

Answer: C
Explanation:
Statement 1 is correct:
Features of Warm Temperate Eastern Margin Climate (China Type):
• Influenced by the on-shore Trade Winds all the year-round, without any monsoon variations.
Statement 2 is correct:
• Fairly uniform distribution of rainfall throughout the year.
• There is rain every month, except in the interior of central China, where there is a distinct dry season.
• Rain comes either from convectional sources or as orographic rain in summer, or from depressions in prolonged showers in winter.
• It is sometimes referred to as the Gulf type or Natal type of climate.
• This type of climate is found on the eastern margins of continents in warm temperate latitudes, just outside the tropics as seen clearly in the below figure:

Answer: C
Explanation:
Statement 1 is correct:
Shale Gas
• Shales are fine-grained sedimentary rocks formed of organic-rich mud that can be rich resources of petroleum and natural gas.
• Shale gas refers to natural gas that is trapped within shale formations due to its low permeability and cannot escape to the surface as easily as conventional natural gas.
Statement 2 is correct:
• Use of Guar gum: Guar gum can quickly turn water into a very thick gel. Adding guar gum increases the viscosity of water and makes high-pressure pumping and the fracturing process more efficient.
• High viscosity water is much more effective at suspending sand grains and carrying them into the fractures.
• The guar bean is grown mainly by farmers in Rajasthan and Haryana.
Statement 3 is correct:
Challenges and Environmental concerns:
• Shale is mostly found about 2,000 meters deep onshore, in areas of human habitation; unlike oil drilling that takes place offshore. Specially designed water bore-wells may be needed in such areas to tackle escaping methane gas. The use of high-power compressors and other equipment could also unsettle local populations, while shale drilling could affect groundwater reserves.
• The gas produced from such reservoir rocks is known as ‘tight gas’ and it requires massive hydraulic fracturing technique. So the potential impacts of hydraulic fracturing locally and downstream of drilling areas are also a big concern. Hydraulic fracturing involves drilling through the water table into deep underground shale gas reserves. Millions of gallons of water are then used to break the shale and release the gas. In theory, all wells should be completely encased until past the water table level.

Answer: C
Explanation:
Statement 1 is correct:
• The Madden Julian Oscillation (MJO) is one of the most important atmosphere-ocean coupled phenomena in the tropics, which has a profound influence on the Indian summer monsoon.
• MJO is a massive weather event consisting of deep convection coupled with atmospheric circulation, moving slowly eastward over the Indian and Pacific Oceans.
• MJO is an equatorial traveling pattern of anomalous rainfall that is planetary in scale.
Statement 2 is correct:
• Each cycle lasts approximately 30–60 days. Also known as the 30-60 day oscillation, 30-60 day wave, or intra-seasonal oscillation (ISO).
Statement 3 is correct:
• The MJO involves variations in wind, sea surface temperature (SST), cloudiness, and rainfall.
• As it moves, strong MJO activity often splits the planet in to two — one in which the MJO is in the active phase and brings rainfall, and the other in which it suppresses rainfall.
• In the active phase, MJO results in more than average rainfall for that time of the year, while in the suppressed phase, the area receives less than average rainfall.
• An active phase is generally followed by a weak or suppressed phase, in which there is little MJO activity.
• Three active MJO periods are witnessed every year on average.

Answer: B
Explanation:
Pair 1 is matched incorrectly:
• A kettle (also known as a kettle lake, kettle hole, or pothole) is a depression/hole in an outwash plain formed by retreating glaciers or draining floodwaters.
• The kettles are formed as a result of blocks of dead ice left behind by retreating glaciers, which become surrounded by sediment deposited by melt water streams as there is increased friction.
Pair 2 is matched correctly:
• An oxbow lake starts as a curve, or meander, in a river. A lake forms as the river finds a different, shorter course. The meander becomes an oxbow lake along the side of the river.
Pair 3 is matched correctly:
• A lagoon is a shallow body of water protected from a larger body of water (usually the ocean) by sandbars, barrier islands, or coral reefs around the Coastal region.
• They are often called estuaries, sounds, bays, or even lakes.
Pair 4 is matched incorrectly:
• The playa, also called pan, flat, or dry lake, is a flat-bottom depression that is caused by Wind erosion and is found in interior desert basins and adjacent to coasts within arid and semi-arid regions, periodically covered by water that slowly filtrates into the groundwater system or evaporates into the atmosphere, causing the deposition of salt, sand, and mud along the bottom and around the edges of the depression.