Daily Prelims Notes 9 August 2024
- August 9, 2024
- Posted by: OptimizeIAS Team
- Category: DPN
Daily Prelims Notes
9 August 2024
Table Of Contents
- WHO lists over 30 pathogens that could potentially start the next pandemic
- DNA profiling and its scientific value in establishing guilt or innocence in the justice system
- On Monetary Policy and Financial Markets
- Why Has the RBI Policy Panel Kept Interest Rates Unchanged for the 9th Time?
- An emerging threat of drug-resistant fungal infections
- Andhra Pradesh seeks Karnataka’s help to address human-elephant conflict
- Government announces waiver for several drugs approved from select countries
- Why Himalayan towns need a different kind of development
- Forest clearance not sought to divert part of Assam wildlife sanctuary, NGT told
- What’s causing Antarctica’s deep-winter heatwave, what could be its fallout?
- Why do stable lands like the Western Ghats, Guiana Shield & the Drakensberg rise vertically? Scientists find answers
1. WHO lists over 30 pathogens that could potentially start the next pandemic
Sub: Sci
Sec: Health
Context:
- WHO updates its list of top pandemic threats, highlighting over 30 dangerous pathogens including Nipah and Mpox.
More on the news:
- In a significant update, the World Health Organization (WHO) has revised its list of priority pathogens, identifying a broader range of viruses and bacteria that pose a potential risk for future pandemics.
- This updated list now includes over 30 pathogens, encompassing well-known threats such as influenza A virus, dengue, and Mpox, as well as emerging threats like the Nipah virus.
What is the ‘Pathogens Prioritization’ report?
- ‘Pathogens Prioritization’ report was released by WHO.
- It outlines the findings of a global pathogen prioritization process involving over 200 scientists from more than 50 countries who evaluated the evidence related to 28 Viral Families and one core group of Bacteria, encompassing 1,652 pathogens.
- This process emphasized the imperative nature of collaborative efforts to attain global resilience against epidemics and pandemics.
- The final list comprises over 30 ‘priority pathogens’.
Key findings of the report:
- Sarbecovirus is classified as ‘high’ in the WHO list, for its risk of causing a Public Health Emergency of International Concern or PHEIC.
- The list also includes Subgenus Merbecovirus, which includes the Middle East Respiratory Syndrome Coronavirus (MERS-CoV).
- The dengue virus and the influenza A viruses, including the H5 subtype, which caused an avian influenza outbreak in India and which even affected cattle in the United States are now on the list.
- In the Southeast Asia region, the report notes, bacterial pathogens are priorities including Vibrio cholera O139 (cholera) and Shigella dysenteriae serotype 1 (dysentery).
What are Prototype pathogens?
- The 2024 report, incorporates for the first time, the concept of the ‘Family approach’ and the ‘Prototype Pathogen’.
- The family approach is important, as pathogens within a family have a lot of similarities, and even share genetic material, meaning an existing treatment option or vaccine for one strain of the pathogen family could potentially be repurposed for another.
- The ‘prototype pathogens are representative pathogens within a family selected to serve as a model for fundamental research to develop medical countermeasures that can be applied to other members of the family.
2. DNA profiling and its scientific value in establishing guilt or innocence in the justice system
Sub: Sci
Sec: Health
- The accuracy of DNA evidence is increasing with the advancement of science with every passing day, thereby making it more and more reliable, but yet we have not reached a juncture where it may be called infallible.
What is DNA profiling?
- DNA profiling is the process where a specific DNA pattern, called a profile, is obtained from a person or sample of bodily tissue.
- Human DNA profiles can be used to identify the origin of a DNA sample at a crime scene or test for parentage.
- Each individual inherits a unique combination of polymorphisms from their parents and these DNA polymorphisms are analyzed to give a DNA profile.
- DNA profiling includes isolation, purification and quantitation of DNA, amplification of selected genetic markers, visualizing the fragments and genotyping, statistical analysis and interpretation, the Kolkata lab explainer adds.
What is the source of DNA profiling?
- DNA can be sourced from any biological material.
- This includes saliva, semen, vaginal fluids, blood, body tissues, teeth, hair, and bones.
- The quantity of DNA contained in biological material varies as blood and saliva are richer sources of DNA as compared to teeth and hair roots, which are DNA deficien
- Touch DNA contains very low amounts of DNA and is not an ideal source for DNA profiling.
How reliable is DNA?
- DNA in all human beings is 99.9% identical.
- In forensic DNA profiling, a few locations in the remaining 0.1% of DNA are chosen to create a person’s DNA profile.
- These specific locations at which the DNA is examined are called loci which have repetitive sequences of DNA called Short Tandem Repeats, or STRs.
- While every individual has the same sequence, or STR, on a locus, the number of times that it repeats itself may vary across individuals.
- The current genetic markers of choice for forensic purposes are STRs.
- STRs present on the Y chromosome are used in sexual assault cases or to determine paternal lineage.
How conclusive is DNA profiling?
- Manikanda Raj, head of forensic medicine and toxicology at Chengalpattu Medical College and Hospital, says DNA analysis as a process is based on probability and, in that sense, cannot be considered conclusive evidence.
- As per the The Madras High Court verdict there are three possible outcomes of a profile comparison-
- (1) Match : If the DNA profiles obtained from the two samples are indistinguishable, they are said to have matched.
- (2) Exclusion : If the comparison of profiles shows differences, it can only be explained by the two samples originating from different sources.
- (3) Inconclusive : The data does not support a conclusion.
- As per the Law Commission of India report If the samples match, that does not mean the identity is conclusively proved.
- Thus, DNA may be more useful for purposes of investigation but not for raising any presumption of identity in a court of law.
3. On Monetary Policy and Financial Markets
Sub: Eco
Sec: Monetary Policy
- Global Monetary Policy Challenges:
- Rapid market volatility has exposed the challenges central banks face when implementing monetary policy amid strong financial markets.
- Central banks, like the Bank of Japan, have made interest rate adjustments (e.g., raising rates) to combat inflation and economic stagnation, leading to significant market disruptions.
- These disruptions underscore the difficulty of managing economic policy in an environment where financial markets react swiftly and unpredictably.
- Interest Rates as a Tool for Economic Management:
- The consensus approach to monetary policy involves using interest rates to balance the trade-off between inflation and unemployment.
- As inflation rises, central banks typically raise interest rates to curb investment and slow aggregate demand, thereby reducing labor demand and controlling wage inflation.
- Criticism of this approach suggests it unfairly burdens workers, who face increased unemployment and a rising cost of living.
- Impact of Financial Markets on Monetary Policy:
- Financial markets often react faster than policymakers can respond, leading to large-scale drops in asset values and potential destabilization.
- The global nature of financial markets means that actions in one country can have significant effects on others, complicating the implementation of domestic monetary policy.
- Recession Fears and Market Expectations:
- Market behavior is often driven by expectations rather than actual economic conditions.
- For example, a weaker-than-expected jobs report in the U.S. led to fears of a recession and a subsequent sell-off in equity markets, despite the economy not being in a recession.
- This highlights how market expectations can prematurely drive economic outcomes.
- The Carry Trade and Global Finance Dynamics:
- The carry trade involves borrowing at low-interest rates in one country (e.g., Japan) to invest in higher-yielding assets elsewhere.
- When the Bank of Japan raised interest rates, it disrupted carry trades, causing investors to sell off assets in other markets to cover increased borrowing costs.
- This scenario illustrates how domestic monetary policy can have unintended global consequences through the interconnectedness of global finance.
- Conclusion:
- The interaction between monetary policy and financial markets is increasingly complex, with financial markets often undermining traditional economic policy tools.
- Policymakers need to adapt their strategies to account for the rapid and volatile nature of financial markets.
- Recent experiences in Japan and the U.S. demonstrate the ongoing challenges and the need for a more nuanced approach to managing the global economy in this interconnected era.
4. Why Has the RBI Policy Panel Kept Interest Rates Unchanged for the 9th Time?
Sub: Eco
Sec: Monetary Policy
- Persistent Food Inflation:
- The RBI’s Monetary Policy Committee (MPC) kept the Repo rate steady at 6.5% for the ninth consecutive time due to persistent food inflation.
- Food inflation remains a significant concern as it could derail the disinflation path, which is crucial for maintaining price stability.
- Impact on Retail Inflation:
- The headline inflation, measured by the year-on-year changes in the all-India Consumer Price Index (CPI), rose to 5.1% in June from 4.8% in May.
- Food inflation contributed around 70% of the overall retail inflation, making it a major factor in the MPC’s decision to keep rates unchanged.
- RBI’s Vigilance on Price Stability:
- RBI Governor emphasized the need for vigilance to prevent spillovers or second-round effects from persistent food inflation.
- The MPC aims to preserve the gains made so far in monetary policy credibility by maintaining a cautious stance on interest rates.
- Economic Forecasts and Growth Projections:
- The RBI has kept the GDP growth projection for FY2025 unchanged at 7.2% and the retail inflation forecast at 4.5%, despite the challenges posed by food inflation.
- The MPC believes that high growth cannot be achieved without price stability, underscoring the importance of controlling inflation.
- Potential for Future Rate Cuts:
- Economists suggest that a rate cut may be possible in December 2024, provided that the inflation situation improves due to a good monsoon and the absence of major domestic or global shocks.
- The RBI is likely to monitor incoming data and exercise caution before deciding on any rate cuts.
- Impact on Lending Rates:
- With the Repo rate unchanged, external benchmark lending rates (EBLR) linked to the Repo rate will remain steady, providing relief to borrowers as their EMIs on home and personal loans will not increase.
- However, lenders may raise interest rates on loans linked to the marginal cost of fund-based lending rate (MCLR), where the full transmission of previous rate hikes has not yet occurred.
- Global Economic Considerations:
- The RBI’s policy decisions are also influenced by global economic events, including potential rate cuts by the US Federal Reserve and geopolitical uncertainties.
- The RBI may consider aligning its monetary policy with the global rate cycle to reduce any significant future policy deviations.
In summary, the RBI’s decision to keep interest rates unchanged for the ninth consecutive time is driven by the need to manage persistent food inflation and ensure price stability while being cautious about future rate cuts.
5. An emerging threat of drug-resistant fungal infections
Subject: Science and Tech
Sec: Health
Context:
The rise of drug-resistant fungal infections, notably Trichophyton indotineae, is emerging as a significant health concern in India. This resilient dermatophyte, linked to the misuse of topical steroids, poses challenges for both patients and healthcare providers.
More on News:
Many who face infections caused by Trichophyton indotineae, commonly known as ringworm or jock itch. First identified in India, this fungus has now spread to several countries worldwide. The inappropriate use of steroid creams has exacerbated the problem, making this strain particularly hard to treat.
This dermatophyte, found in various regions including Australia and Oman, belongs to genotype VIII within the T. mentagrophytes/T. interdigitale species complex.
Clinical Challenges and Symptoms:
- Patients often present with persistent, treatment-resistant rashes that can easily be mistaken for eczema or other skin conditions, delaying effective treatment.
- These rashes can be red, scaly, and itchy, making them similar to more common dermatological issues.
- The diagnostic process involves not just clinical examination but also laboratory tests, such as fungal cultures and molecular diagnostics, to confirm the presence of resistant fungal strains.
- Misdiagnosis and delayed treatment can lead to the spread of the infection, not only worsening the individual’s condition but also increasing the risk of transmission within the community.
Treatment options :
- Trichophyton indotineae is a newly-identified dermatophyte species that has been found in near-epidemic form on the Indian subcontinent.
- This fungus, identical to genotype VIII within the T. mentagrophytes/T. interdigitale species complex, was described in 2019 by sequencing the Internal Transcribed Spacer (ITS) region of ribosomal DNA.
- More than 10 ITS genotypes of T. interdigitale and T. mentagrophytes can now be identified. T. indotineae causes inflammatory and itchy, often widespread dermatophytosis affecting the groins, gluteal region, trunk, and face, affecting patients of all ages and genders.
- Alternative treatments such as itraconazole may be necessary. However, these alternatives often come with significant side effects, including gastrointestinal issues, liver toxicity, and interactions with other medications, and will require close monitoring by healthcare providers.
- One of the major reasons this is happening is the itraconazole drug formulations available are not of good quality. This results in suboptimal dosing, even if patients take it as prescribed. Unregulated sales of steroid-containing combination creams that may temporarily reduce the itch but contribute to resistance further complicate treatment efforts.
- Regular follow-ups with healthcare providers are essential to ensure effective management.
- Monitoring the patient’s response to treatment allows for timely adjustments to the treatment plan.
Prevention strategies:
Healthcare professionals strongly advise against the unsupervised use of combination creams containing steroids and antifungals, as these can contribute to drug resistance and worsen infections.
Public awareness campaigns are crucial to inform the public about the risks of self-medication and the importance of consulting healthcare professionals for skin conditions.
Maintaining good hygiene practices.
- Keeping the skin dry and clean is essential since moisture creates an ideal environment for fungal growth.
- Regularly washing and drying areas prone to sweating, such as the feet, groin, and armpits, can help reduce this risk.
- Avoiding sharing of personal items like towels, clothing, and grooming tools is another important preventive measure.
- Wearing breathable clothing, particularly loose-fitting fabrics like cotton, helps keep the skin dry and reduces sweating.
- Proper footwear, along with regular cleaning of bed linens, towels, and clothing in hot water, can kill fungal spores and reduce the risk of infection.
Public health concerns in India:
- Indians, living in a land that has a tropical climate and high population density, are particularly vulnerable to fungal infections.
- The prevalence of Trichophyton indotineae is a growing public health concern, especially in rural areas where access to healthcare is limited.
- Public health initiatives must focus on improving diagnostic facilities and ensuring the availability of effective treatments.
6. Andhra Pradesh seeks Karnataka’s help to address human-elephant conflict
Subject: Env
Sec: Species in news
Context:
Andhra Pradesh Deputy Chief Minister Pawan Kalyan met Environment Minister Eshwar Khandre and sought the help of the Karnataka Forest Department to tackle man-elephant conflict in his State.
More on News:
- The Kumki elephants, which take part in Jumbo Savari during the Dasara celebrations in Mysuru, would not be given.
- They have around 103 semi-trained kumki elephants in our elephant camps.
- Karnataka has sent 67 kumki elephants to various States.
- In 2022-23, four elephants were sent to Uttar Pradesh, 14 to Madhya Pradesh, and three to Maharashtra.
MoU:
- A memorandum of understanding (MoU) is a type of agreement between two (bilateral) or more (multilateral) parties.
- Formal institutional arrangement between Andhra Pradesh and Karnataka Forest Departments for addressing man-animal conflict, deploying expert teams for elephant capturing, mahout training, training programme in running elephant camps, knowledge transfer, standard operating procedure for darting and capture of elephants, provide expertise in nutrition and food, workshop etc.
- During the meeting, Karnataka Forest officials disclosed to the Andhra Pradesh counterparts that they had seized ₹140 crore worth of red sanders in the State, which was smuggled from Andhra Pradesh.
Elephants
- Elephants in India:
- Elephants are keystone species as well as the Natural Heritage Animal of India.
- India has the largest number of wild Asian Elephants. The elephant population in the country is estimated to be over 30,000.
- Karnataka has the highest elephant population in India.
- Conservation Status:
- Convention of the Migratory Species (CMS): Appendix I
- Wildlife (Protection) Act, 1972: Schedule I
- International Union for Conservation of Nature (IUCN) Red List of threatened species:
- Asian Elephant: Endangered
- African Forest Elephant: Critically Endangered
- African Savanna Elephant: Endangered
- Conservative Efforts:
- India:
- Gaj Yatra
- Project Elephant
- Global:
- Monitoring of Illegal Killing of Elephants (MIKE) Programme.
- World Elephant Day.
- India:
- Status of Elephant Corridors in India:
- The key findings of the Elephant Corridors of India, 2023 Report are as follows:
- The report highlighted a surge of 62 new corridors, marking a 40% increase since 2010, now totalling 150 corridors across the nation.
- West Bengal has the highest number of elephant corridors, totalling 26, constituting 17% of the total corridors.
- The East central region contributes 35% (52 corridors), and the North East region follows as the second-largest with 32% (48 corridors).
- Southern India registered 32 elephant corridors, representing 21% of the total, while northern India has the lowest count of 18 corridors, amounting to 12%.
- Elephants have expanded their ranges in the Vidarbha region of Maharashtra and southern Maharashtra bordering Karnataka.
- The key findings of the Elephant Corridors of India, 2023 Report are as follows:
7. Government announces waiver for several drugs approved from select countries
Subject: Science and Tech
Sec: Health
Context:
In a decision that would make drugs manufactured outside India more accessible and affordable in the local market the Central government has decided to waive the requirement for clinical trials in India if the drugs are approved in the United States, United Kingdom, Japan, Australia, Canada, and European Union.
More on News:
- The Central Government has specified a set of five categories for new drugs that will be considered for the Indian market.
- Drugs including vaccines that fall in the category — orphan drugs for rare diseases, gene and cellular therapy products, new drugs used in pandemic situations, new drugs used for special defence purposes, and new drugs having significant therapeutic advances over the current standard care – will be considered under the waiver.
- India’s drug regulatory agency, Central Drugs Standard Control Organisation (CDSCO), the Central Government has authorised the exemption of local clinical trials for approval of new drugs, ‘as per Rule 101’.
- As per Rule 101 of New Drugs and Clinical Trial Rules, 2019 the Central Licensing Authority, with approval of the Central Government, may specify by an order, the name of the countries from time to time for considering waiver of local clinical trial for approval of new drugs under Chapter X and for grant of permission for conduct of clinical trial under Chapter V of the said rules.
- The order has been a long standing demand of the pharmaceutical companies and health experts who have been advocating for enhanced drug accessibility for patients and for research.
- Anil Matai, director general, Organisation of Pharmaceutical Producers of India (OPPI) reacting to the announcement said that this a welcome and progressive move that will significantly benefit both domestic and foreign drug manufacturers by expediting the approval process and facilitating faster access to essential medications for Indian patients.
- The inclusion of specific categories such as orphan drugs for rare diseases, gene and cellular therapy products, new drugs used in pandemic situations, those for special defense purposes and new drugs with significant therapeutic advance over the current standard care would address critical and unmet medical needs.
CDSCO:
- The Central Drugs Standard Control Organisation (CDSCO)under Directorate General of Health Services, Ministry of Health & Family Welfare, Government of India is the National Regulatory Authority (NRA) of India.
- The New drugs and Clinical trials rules 2019 (New rules) was introduced on 19thMarch 2019 by Government of India.
- New rules have set specific requirements for ethics committee (EC). The EC is required to follow requirements set as per New rules and to forward their report to Central Licensing Authority (CLA).
- The new rules define orphan drugs – for the first time – as drugs to treat conditions affecting less than 500,000 people in India.
- As per the new rules, Indian regulators have now been empowered to exempt orphan drugs from Phase III and IV clinical trials.
- On 13 January 2021, the Government of India introduced a Comprehensive ‘National Policy For Rare Diseases 2021’ (which included – Research & development to manufacture orphan drugs, treatment of rare diseases, etc.), replacing its ‘National Policy for Treatment of Rare Diseases 2017’.
Rule 101 of CDSCO:
- Rule 101 allows the Drugs Controller General of India (DCGI) to specify certain countries for considering waiver of local clinical trials for approval of new drugs.
An Orphan Drug:
- An Orphan Drug is a medicine or other medical product used to diagnose, prevent, and treat a life-threatening chronic condition or disorder.
- It is called an ‘orphan drug’ because of its limited market (which is rare, with about 450 rare diseases recorded in India so far), and is unlikely to be adopted by a pharmaceutical company.
- By selling only to a small group of patients, a drug manufacturer will likely not be able to recover the development and marketing costs, so the Government of India has implemented a new ‘National Policy for Rare Diseases (NPRD)’ in the year 2021 to encourage the production of these Orphan drugs.
8. Why Himalayan towns need a different kind of development
Sub: Geo
Sec: Indian physical geo
Context:
- The Indian Himalayan Range (IHR), which includes 11 States and two Union Territories, experienced a decadal urban growth rate of over 40% from 2011 to 2021. However, Himalayan towns require a distinct approach to urbanisation.
What is happening in IHR towns?
- Himalayan towns, including State capitals like Srinagar, Guwahati, Shillong, and Shimla, struggle with civic issues, particularly in sanitation, waste management, and water supply.
- Planning institutions often adopt models from the plains, which are ill-suited for the unique challenges of these regions, and face a severe shortage of human resources, with up to 75% of positions unfilled.
- Cities are expanding into peripheral areas, encroaching on village commons, open spaces, forest land, and watersheds, as seen in Srinagar, where significant land use changes have occurred between 2000 and 2020.
- Water bodies are shrinking, and untreated liquid waste pollutes the remaining water sources.
Why is this happening?
- The IHR is under intense pressure from urbanisation, development, high-intensity tourism, and unsustainable infrastructure, exacerbated by climatic variations such as changing precipitation patterns and rising temperatures.
- This has led to water scarcity, deforestation, land degradation, biodiversity loss, and increased pollution, threatening the socio-ecological fabric of the region.
- Tourism, with an anticipated average annual growth rate of 7.9% from 2013 to 2023, often results in the replacement of eco-friendly infrastructure with inappropriate and unsightly constructions, harming biodiversity and ecosystem services.
What needs to be done?
- Urban planning in IHR cities should be based on comprehensive mapping of geological and hydrological vulnerabilities, involving local communities and following a bottom-up approach.
- The current consultant-driven planning processes should be replaced with climate-resilient urban designs tailored to the region’s unique needs.
- Given that IHR cities cannot generate sufficient capital for infrastructure, the Finance Commission should include a chapter on urban financing specifically for the IHR, and intergovernmental transfers should be increased from 0.5% to 1% of GDP.
- Himalayan towns must prioritize sustainability, focusing on eco-centric planning and public participation to ensure a resilient urban future.
Source: TH
9. Forest clearance not sought to divert part of Assam wildlife sanctuary, NGT told
Sub: Env
Sec: Protected Area
Context:
- The Assam government did not obtain the required forest clearance for non-forestry activities in the Sonai-Rupai Wildlife Sanctuary.
Details:
- The Ministry informed the NGT that it did not receive any proposal for forest clearance for activities in Sonai-Rupai, though such activities require approval under the Van (Sanrakshan Evam Samvardhan) Adhiniyam, 1980.
- Assam’s Principal Chief Conservator of Forests (PCCF) acknowledged that Sonai-Rupai and Charduar, along with three other protected areas—Balipara Reserve Forest, Senglimari Reserve Forest, and Naduar Reserve Forest—are under significant encroachment.
Sonai- Rupai Wildlife Sanctuary:
- Located in the state of Assam in India.
- It is located along the foothills of the Great Himalayan Range. The area was declared a sanctuary in 1998.
- Four rivers flow through the sanctuary: Gabharu, Gelgeli, Sonai and Rupai.
- Wildlife:
- Mammals: tiger, lesser cats, elephant, gaur, wild boar, pygmy hog, swamp deer and barking deer.
- Birds: white-winged wood duck, hornbill, pelican, and various migratory birds.
- Reptiles: python, Russell’s viper.
Source: TH
10. What’s causing Antarctica’s deep-winter heatwave, what could be its fallout?
Sub: Geo
Sec: Climatology
Record-breaking Heatwave in Antarctica:
- Antarctica is experiencing a record-breaking heatwave for the second time in two years, with ground temperatures averaging 10 degrees Celsius higher than normal and reaching up to 28 degrees higher on certain days.
- In East Antarctica, temperatures are currently between minus 25 degrees to minus 30 degrees Celsius, compared to the usual minus 50 to minus 60 degrees Celsius during deep winter.
Reasons for the Heatwave:
- The heatwave is mainly due to the weakening of the polar vortex, which usually traps cold air over Antarctica but was disturbed this year by large-scale atmospheric waves. This allowed warmer air to enter the region, causing an increase in temperatures.
- A weakened southern hemisphere vortex is a rare event, typically occurring once every two decades, making this an unusual occurrence.
- Other contributing factors include the reduction of Antarctic sea ice, which plays a crucial role in maintaining low temperatures by reflecting sunlight and acting as a barrier between cold air and warmer water.
Impact of Global Warming:
- Global warming is affecting Antarctica more severely than other parts of the planet, with the continent warming at nearly twice the rate of the global average.
- The Antarctic Ice Sheet, which holds over 60% of the world’s freshwater, is at risk of further loss due to rising temperatures.
Possible Fallouts:
- The heatwave may lead to further losses of the Antarctic Ice Sheet, which could raise global sea levels by hundreds of feet, threatening coastal cities and displacing millions of people.
- In March 2022, a previous heatwave led to the collapse of a portion of the ice sheet the size of Rome.
- Rising temperatures in Antarctica could also impact the global ocean circulation system, which is responsible for regulating climate.
- Melting ice slows down this circulation, leading to oceans absorbing less heat and CO2, thereby intensifying global warming and increasing the frequency of extreme weather events like floods and droughts.
Source: IE
Sub: Geo
Sec: Geomorphology
Context:
- A new study reveals that the splitting of continents can cause significant topological changes in distant stable lands, such as the formation of plateaus and escarpments (steep slopes).
Tectonic Movements and Lithosphere Thinning:
- When tectonic plates move apart, the lithosphere, consisting of the upper mantle and crust, thins, leading to the splitting of a continent. During this process, steep coastal escarpments form at the rift margins, marking the transition between continents and oceans, while interior plateaus rise inland.
Impact on Cratons and Vertical Uplift:
- The study explains why cratons, stable parts of continents like the Sahyadri hill range in the Western Ghats, eastern Brazil, and southern Africa, which are far from rift zones, experience vertical uplift.
- This is due to a ‘deep mantle wave’ triggered by the continental breakup, which travels along the continent’s base and removes layers of rock, causing the continents to rise through a process called isostasy.
Climate Impact and Biodiversity
- The formation of escarpments and elevated plateaus can lead to extreme erosion, which helps draw down carbon dioxide from the atmosphere.
- Additionally, these topological changes create physical barriers that drive the formation of new species by forcing populations to adapt to different ecological niches.
- The uplift of land by hundreds of meters to over a kilometre can either push plants out of their comfort zones or compel them to adapt to new climatic conditions. Researchers aim to determine if this process occurs globally in other continental regions.
Source: DTE