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Journalism of Courage
UPSC Essentials brings to you its initiative for the practice of Mains answer writing. It covers essential topics of static and dynamic parts of the UPSC Civil Services syllabus covered under various GS papers. This answer-writing practice is designed to help you as a value addition to your UPSC CSE Mains. Attempt today’s answer writing on questions related to topics of GS-1 to check your progress. Since we are resuming the GS 1 mains answer writing practice after a gap of a week, please attempt 4 questions this week to cover Weeks 89 and 90.
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What are deep-focus earthquakes, and how do they differ from shallow-focus earthquakes in terms of impact and origin?
The Sundarbans mangrove ecosystem plays a crucial role in climate resilience and biodiversity conservation. Discuss the findings of the recent study “Global Mangrove Alliance Report on the Sundarbans”.
Marine heatwaves pose a growing hazard to worldwide marine ecosystems and coastal economies. Examine the causes and effects of maritime heatwaves. What steps can be taken to lessen their impact?
The western coast of India around Mumbai has witnessed unusually high temperatures, raising concerns about changing climate patterns. Analyse the factors contributing to this anomaly.
Introduction
— The introduction of the answer is essential and should be restricted to 3-5 lines. Remember, a one-liner is not a standard introduction.
— It may consist of basic information by giving some definitions from the trusted source and authentic facts.
Body
— It is the central part of the answer and one should understand the demand of the question to provide rich content.
— The answer must be preferably written as a mix of points and short paragraphs rather than using long paragraphs or just points.
— Using facts from authentic government sources makes your answer more comprehensive. Analysis is important based on the demand of the question, but do not over analyse.
— Underlining keywords gives you an edge over other candidates and enhances presentation of the answer.
— Using flowcharts/tree-diagram in the answers saves much time and boosts your score. However, it should be used logically and only where it is required.
Way forward/ conclusion
— The ending of the answer should be on a positive note and it should have a forward-looking approach. However, if you feel that an important problem must be highlighted, you may add it in your conclusion. Try not to repeat any point from body or introduction.
— You may use the findings of reports or surveys conducted at national and international levels, quotes etc. in your answers.
Self Evaluation
— It is the most important part of our Mains answer writing practice. UPSC Essentials will provide some guiding points or ideas as a thought process that will help you to evaluate your answers.
QUESTION 1: Recent earthquakes in Delhi-NCR, including the “Dawn Quake,” highlight the seismic vulnerability of the region. What are deep-focus earthquakes, and how do they differ from shallow-focus earthquakes in terms of impact and origin?
Introduction:
— An earthquake is a phenomenon that strikes unexpectedly and causes tremendous shaking of the ground and everything on it. It comes from the release of accumulated stress from moving lithospheric or crustal plates.
— Earthquakes are tectonic in origin, which means that shifting plates cause strong shakings. An earthquake in a densely populated area can result in multiple casualties, injuries, and substantial property damage.
— The recent tremors in Delhi were the largest earthquake to originate in the city in at least five years, according to data from the National Centre of Seismology.
Body:
Deep-focus earthquakes and shallow-focus earthquakes
— Shallow earthquakes range in depth from 0 to 70 km, intermediate earthquakes from 70 to 300 km, and deep earthquakes from 300 to 700 km. In general, the term “deep-focus earthquakes” refers to earthquakes that occur deeper than 70 km. All earthquakes deeper than 70 km occur within large slabs of lithosphere that sink into the Earth’s mantle.
— The strength of shaking from an earthquake decreases with increasing distance from its source, hence the strength of shaking at the surface from a 500 km deep earthquake is significantly less than if the same earthquake occurred at a depth of 20 km.
— Furthermore, earthquake depths provide valuable information on the Earth’s structure and the tectonic setting in which the earthquakes occur. The most visible example of this is at subduction zones, where plates collide and one is subducted beneath another.
Conclusion:
— The Aravalli-Delhi Fold Belt, which stretches from southern and eastern Rajasthan to Haryana and Delhi, is notable for its seismic activity. This region is distinguished by the presence of deformed strata of rock that have been folded or bent as a result of geological processes hundreds of million years ago. These deformities have generated stress, which is occasionally released in the form of earthquakes.
— This is a totally different mechanism than the one that causes earthquakes in the Himalayan region, which is one of the world’s most seismically active areas. The Himalayan region has been seeing the subduction of the Indian tectonic plate beneath the Eurasian plate — one pushing against the other — resulting in significant tension buildup.
(Source: The dawn quake: How tremors in Delhi are different from earthquakes in the Himalayan region by Amitabh Sinha, ndma.gov.in, http://www.usgs.gov)
Points to Ponder
Recent examples of earthquake
Earthquake prone region in India
What is the difference between P and S waves
Related Previous Year Questions
Discuss about the vulnerability of India to earthquake related hazards. Give examples including the salient features of major disasters caused by earthquakes in different parts of India during the last three decades. (2021)
The frequency of earthquakes appears to have increased in the Indian subcontinent. However, India’s preparedness for mitigating their impact has significant gaps. Discuss various aspects. (2015)
QUESTION 2: The Sundarbans mangrove ecosystem plays a crucial role in climate resilience and biodiversity conservation. Discuss the findings of the recent study “Resilience of Sundarban Mangroves in South Asia to Weather Extremes and Anthropogenic Water Pollution”.
Introduction:
— Mangroves are the only trees that can survive in salty water near the sea.
— Mangroves play an essential role in another critical process called carbon sequestration, which involves the removal of carbon dioxide from the atmosphere.
— The mangroves act as the first line of defence against cyclones, home to a large variety of birds, animals and insects, and helping the fight against global warming.
— For example, the Sundarbans are located in the delta formed by the Ganga, Brahmaputra, and Meghna rivers off the coast of Bengal.
Body:
— According to a Global Mangrove Alliance report on the Sundarbans, “Threatened and endangered wildlife — like the Bengal tiger, Irrawaddy river dolphin, finless porpoise, and estuarine crocodile — live here. The mangroves also serve as a bio-shield for the fierce waves and winds of coastal storms.”
Key findings of the report
— The study, ‘Resilience of Sundarban Mangroves in South Asia to Weather Extremes and Anthropogenic Water Pollution,’ examined the nutrient profile available to mangroves in the soil from 2013 to 2015 and investigated their reaction to it. It also investigated how mangroves respond to natural occurrences such as cyclones. It was accomplished by investigating the mangroves’ interactions with a range of elements such as water, wind, water vapour, and sunlight.
— Mangroves recover swiftly from physiological stresses caused by weather extremes, within one to two weeks, and sustain steady productivity in the face of dramatically dropping nutrient content owing to human-induced water pollution.
— Mangroves recover swiftly from physiological stresses caused by weather extremes, within one to two weeks, and sustain steady productivity in the face of dramatically dropping nutrient content owing to human-induced water pollution.
— The Redfield Ratio, which has an optimal value of 106:16:1, was used to establish “steeply declining nutrient composition” in the study. Nitrates have increased, but phosphorus has reduced.
Conclusion:
— A big and complex plant system, such as mangroves, is linked by multiple variables, including entangled roots, shared nutrients and soil composition, and shared stressors. Memory in plants refers to “remembering” how they behaved to a previous stressful event, such as a cyclone, and storing that response for future reference.
— Although the Sundarbans have demonstrated resilience, their ability to self-repair is limited. The study sheds light on the issues that the Sundarbans face and represents one step ahead in the search for strategies to safeguard and maintain them.
(Source: Sundarbans are resilient in face of natural, manmade stress: A new study highlights how by Yashee)
Points to Ponder
Location of Sundarbans mangroves forests
Other mangroves forests in India
Importance of mangroves
Flora and fauna found in Sundarbans
Related Previous Year Questions
Identify and discuss the factors responsible for diversity of natural vegetation in India. Assess the significance of wildlife sanctuaries in rainforest regions of India. (2023)
Examine the status of forest resources of India and its resultant impact on climate change. (2019)
QUESTION 3: Marine heatwaves pose a growing hazard to worldwide marine ecosystems and coastal economies. Examine the causes and effects of maritime heatwaves. What steps can be taken to lessen their impact?
Introduction:
— A maritime heatwave is considered an extreme weather occurrence. It occurs when the surface temperature of a specific area of the water rises by 3 or 4 degrees Celsius over the usual temperature for at least five days.
— According to the US National Oceanic and Atmospheric Administration (NOAA), marine heatwaves (MHWs) can endure for weeks, months, or even years.
— According to a 2021 report by the International Union for Conservation of Nature (IUCN), MHWs have increased by 50% over the last decade, lasting longer and becoming more severe. MHWs can affect tiny regions of coastline or entire oceans.
Body:
Causes of marine heatwaves
— The primary cause is the climate problem. As global temperatures have risen by 1.3 degrees Celsius above pre-industrial levels, the ocean has absorbed 90% of the excess heat.
— The situation is anticipated to worsen not only in Western Australia, but around the world. According to the 2018 study, the current number of MHWs is expected to increase on average by a factor of 16 for 1.5 degrees Celsius of global warming and a factor of 23 for 2.0 degrees Celsius.
What is the impact of marine heatwaves?
— MHWs can be harmful to marine life. For example, the 2010-11 MHWs in Western Australia resulted in large-scale fish kills, which are the abrupt and unexpected deaths of a significant number of fish or other aquatic species over a short period of time and primarily in one area.
— It also destroyed kelp forests and significantly changed the coastal environment. Kelps typically develop in cooler waters, providing habitat and food for a variety of marine species.
— These heat waves contribute to coral bleaching, which lowers coral reproduction and increases their susceptibility to life-threatening diseases.
— Thousands of marine creatures rely on coral reefs for living, and damage to corals could jeopardise their existence.
— In 2024, coral bleaching on Australia’s Great Barrier Reef reached “catastrophic” levels after intense MHWs put corals under stress. This was the reef’s seventh mass bleaching event.
Steps that can be taken to lessen their impact
— To mitigate the effects of the climate problem, governments must invest in natural solutions and reduce emissions from fossil fuels aggressively.
— More research, improved prediction and warning systems.
— Regional efforts to improve ocean resilience can help safeguard communities and ecosystems against MHWs.
Conclusion:
— Climate warming has increased the likelihood of marine heatwaves that killed over 30,000 fish off the coast of Western Australia in January by up to 100 times.
— Marine heat waves endanger marine biodiversity and ecosystems, exacerbate extreme weather, and harm the fisheries, aquaculture, and tourism industries.
(Source: How the climate crisis has intensified marine heatwaves across the world by Alind Chauhan, iucn.org)
Points to Ponder
What is the difference between heat waves and marine heat waves?
What are kelp forests?
What is coral bleaching?
Related Previous Year Questions
What are the consequences of spreading ‘Dead Zones’ on marine ecosystems? (2018)
(a) Bring out the causes for the formation of heat islands in the urban habitat of the world. (b) What do you understand about the phenomenon of ‘temperature inversion’ in meteorology? How does it affect the weather and the habitants of the place? (2013)
QUESTION 4: The western coast of India around Mumbai has witnessed unusually high temperatures, raising concerns about changing climate patterns. Analyse the factors contributing to this anomaly.
Introduction:
— Climate change refers to long-term changes in temperature and weather patterns. Such fluctuations may be natural, due to variations in the sun’s activity or huge volcanic eruptions. However, since the 1800s, human activities have been the primary cause of climate change, owing to the combustion of fossil fuels such as coal, oil, and gas.
— Burning fossil fuels produces greenhouse gas emissions, which act as a blanket over the Earth, trapping the sun’s heat and boosting temperatures.
— The highest temperature was 36 degrees on February 13 and 36.7 degrees on February 14, both more than five degrees above normal. On February 15, the India Meteorological Department’s Santacruz station recorded a high temperature of 36.1 degrees.
Body:
Factors contributing to the rise in temperature on the western coast of India around Mumbai
— Sunil Kamble, Director of IMD Mumbai, stated that easterly winds are blowing till around midday, at which point the wind direction changes to north-westerly, causing temperatures to rise during the day.
— The north-westerly winds in the afternoon cause a jump in daytime temperatures, whilst the easterly breezes in the early hours are milder.
— The IMD has also noted the absence of western disturbances that often bring rain in February. These weather patterns bring milder northerly breezes to Mumbai, lowering temperatures in the city.
— The northwesterlies blowing into the city were caused by an anticyclonic system over the Arabian Sea. Because of the anticyclone system off the west coast of the Arabian Sea, winds are travelling clockwise, resulting in the arrival of north-westerly winds.
— Clear skies and bright sunlight during the day have resulted in greater maximum temperatures and speedier cooling at night.
Conclusion:
— Climate change has made Indian coastal towns more prone to heat stress, which causes physiological stress in the workplace.
— Coastal cities in India experience severe heat waves, owing to a considerable increase in the variety in heat wave characteristics such as length, frequency, and intensity across the country’s urban areas.
(Source: Why Mumbai is sweating this February: Anticyclone above the sea, other factors by Nayonika Bose, http://www.un.org)
Points to Ponder
What is a diurnal range?
What is an anticyclone system?
Read more about north-westerly winds
Related Previous Year Questions
What is sea surface temperature rise? How does it affect the formation of tropical cyclones? (2024)
Discuss the consequence of Climate change on the food security in tropical countries. (2023)
UPSC Essentials: Mains answer practice — GS 3 (Week 90)
UPSC Essentials: Mains answer practice — GS 3 (Week 89)
UPSC Essentials: Mains answer practice — GS 2 (Week 90)
UPSC Essentials: Mains answer practice — GS 2 (Week 89)
UPSC Essentials: Mains answer practice — GS 1 (Week 88)
UPSC Essentials: Mains answer practice — GS 1 (Week 87)
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