Content

1. Judiciary Cannot Impose Timelines on President/Governor for Bill Assent
2. AI-Driven Transformation of Election Data Analysis in India
3. South Asia’s Transboundary Air Pollution Crisis
4. Over 50% Cases Pending in Juvenile Justice Boards: India Justice Report
5. Second-Generation Wild Cheetah Birth in India: Milestone for Project Cheetah
6. India’s Indigenous CRISPR Gene Therapy Breakthrough: Birsa-101
7. Mount Semeru Eruption: Why Volcanic Eruptions Occur and Why Some Are Explosive

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Judiciary Cannot Tie President or Governor to Timelines 

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Why Is It in News?

• A 5-judge Constitution Bench delivered its opinion on the 16th Presidential Reference.
• The Court held that:
  • Judiciary cannot impose fixed timelines on the President/Governors for assent to State Bills.
  • Judiciary cannot presume “deemed consent” if they fail to act within a court-mandated deadline.
• The Court simultaneously criticised “prolonged and evasive inaction” by Governors and the Centre.

Relevance  

GS-2: Polity, Constitution, Governance

• Federal relations (Centre–State dynamics).
• Powers & discretion of Governor/President.
• Doctrine of separation of powers.
• Judicial review and limits of judicial activism.
• Article 200–201 interpretation.

GS-2: Executive–Legislature Relations

• Impact of delayed assent on State legislative functioning.

GS-2: Constitutional Bodies

• Presidential Reference jurisdiction under Art. 143.

Constitutional Provisions on Assent to Bills

Articles Involved

• Art. 200: Governor’s options on State Bills—
  • Assent
  • Withhold assent
  • Return for reconsideration
  • Reserve for President
• Art. 201: President’s options—
  • Assent
  • Withhold assent
  • Return (if not a Money Bill)
• No explicit time limit in Constitution for either office to act.

Principle of Constitutional Morality

• Offices must act “within a reasonable time” as part of constitutional trust.

What Triggered the Presidential Reference?

• Growing friction between Opposition-ruled States and Governors.
• Allegations of:
  • Bills being kept pending for months/years.
  • Governors reserving Bills excessively for the President.
• High Courts (notably Madras HC) began discussing soft timelines.
• Union Government sought clarity via Presidential Reference.

Supreme Court’s Key Findings

A. Judiciary cannot prescribe hard timelines

• Timelines imposed by courts are “one-size-fits-all” and violate:
  • Separation of Powers (basic structure).
  • Explicit constitutional design of discretionary spaces for constitutional heads.

B. No “deemed consent” at expiry of timelines

• Courts cannot assume assent if deadlines lapse.
• Such assumption = judiciary usurping constitutional functions.

C. But constitutional heads cannot sit indefinitely

• Court strongly criticised “prolonged and evasive inaction” by Governors/President.
• Observed:
  • Constitutional heads must record reasons, avoid indefinite delay.
  • Inaction cannot be used as a political veto.

D. Presidential Reference is NOT an “appeal in disguise”

• Some States argued the Centre used this as an appeal against unfavourable HC rulings.
• SC held:
  • Advisory opinions can correct or clarify the law.
  • Not bound by lower court decisions.

Constitutional Overview

A. Doctrine of Separation of Powers (cited by Court)

• Cites Kesavananda Bharati, Indira Gandhi, Puttaswamy.
• Judiciary cannot intrude into executive discretion of constitutional offices.

B. Federal Balance

• Constitution assigns the Governor a limited discretionary role, not a political one.
• Indefinite delays threaten:
  • Basic federalism (S.R. Bommai, Nabam Rebia).
  • Legislative autonomy of States.

C. Reasonableness Standard

• Though no timelines prescribed, Court implies:
  • “Reasonable time” must be context-specific.
  • Non-action is reviewable if it becomes arbitrary or mala fide.

Related Case Law

• Nabam Rebia (2016): Governor cannot interfere with legislative process except where Constitution permits.
• Shamsher Singh (1974): Governor acts on aid & advice, except in limited areas.
• Rameshwar Prasad (2006): Discretion subject to judicial review if mala fide.

Implications for Centre–State Relations

Positive

• Reaffirms judicial restraint.
• Avoids courts overriding federal constitutional design.

Concerns

• Gives administrative space for Governors to delay Bills.
• States fear misuse in politically sensitive Bills.

Net Effect

• A balanced but status-quo reinforcing opinion:
  • No mandatory deadlines.
  • Strong moral-constitutional rebuke of delays.

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Election Data Analysis: From the Dark Ages to the AI Era

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Why Is It in News?

• The Article published a reflective analysis on how election-related data journalism evolved from manual scraping in 2017 to full AI-driven code generation during the 2025 Bihar Assembly elections.
• Marks a technological inflection point:
  • Entire election-night mapping, charting, and analysis produced using AI-generated scripts.
  • Demonstrates how AI reshapes media workflows without replacing journalists.
• Raises policy questions on data access, algorithmic transparency, media ethics, and election integrity.

Relevance  

GS-2: Governance

• Transparency in electoral information.
• Role of technology in elections.
• Data access, public accountability.

GS-3: Science & Tech

• AI adoption in public communication.
• Algorithmic governance & data systems.

GS-3: Cybersecurity

• Risks of automated misinformation.
• Need for secure election data pipelines.

What Is Election Data Analysis?

• Systematic extraction, cleaning, mapping, and interpretation of election results & political patterns.
• Core components:
  • Scraping live results from Election Commission.
  • Constituency-level mapping.
  • Vote-share/swing calculations.
  • Trend/seat projections.
  • Visualisations for public communication.

Pre-2017 “Dark Ages” – Manual & Slow

A. Manual Data Scraping

• Live results had to be copied/scraped manually.
• Slow scraping due to:
  • Limited coding skills.
  • Unstable ECI website structure.
• Results flowed like “water droplets” into spreadsheets.

B. Mapping Challenges

• Tools used: Google Fusion Tables, Indiemapper.io.
• Manual KML boundaries, manual colour-coding.
• Duplication of effort for colour and monochrome print versions.

C. Charting

• Copy-pasting data → Excel → pivot tables → charts.
• High human dependency & narrow deadlines.

2017–2019: Transition to “Industrial Tools”

Key Shifts

• Tableau adopted for mapping → reduced processing time.
• Faster scripts due to communities like Stack Exchange.
• Partial automation in Google Sheets (formulae, scripts).
• Enabled simultaneous print + web coverage.

Limitations

• Heavy manual interventions required.
• Tools remained fragmented (separate for maps, charts, tables).

2019–2024: The Industrial Revolution

Characteristics

• Heavy machinery, faster workflows.
• Automated formula pipelines.
• More realtime analysis, especially during 2019 and 2023 elections.
• Still required:
  • Script debugging
  • Cross-tool integration
  • Designer intervention for visuals

2025 Bihar Assembly Election – The AI Era

A. AI-Generated Code

• Google AI Studio generated mapping + scraping + visualization scripts.
• JupyterLab executed AI-written pipelines.
• No need for:
  • Tableau
  • Excel pivot tables
  • Mapping software
  • Manual charting tools

B. What AI Automated

• Live data ingestion
• Data cleaning & transformation
• Charting (auto-generated)
• Geo-mapping
• Statistical summaries
• First-draft insights

C. Output Gains

• Faster online analysis.
• Backend + frontend automation for livestreams.
• Print edition wrapped up by 10:30 PM (earlier than ever).

Why AI Didn’t Replace Journalists

Core Functions Still Human

• Interpretation of trends.
• Identifying misleading patterns.
• Contextualising swings, alliances, caste shifts.
• Writing coherent narratives.
• Editorial judgement and ethics.

The Principle

• AI accelerates production; journalists give meaning.

Deeper Analysis: Impact on Indian Democracy & Media

A. Strengthening Public Information

• Faster dissemination → more informed electorate.
• Real-time mapping exposes micro-trends (regional, demographic).

B. Risks

• Data quality vulnerability: Errors in source data propagate quickly.
• Algorithmic opacity: AI-generated code may be non-auditable.
• Deepfake + misinformation risks if AI visualisations are misused.
• Over-automation reduces cross-verification, increasing error probability.

C. Digital Divide

• Smaller media houses without AI capability may be disadvantaged.

Structural Issues Highlighted

A. Election Commission Website

• Historically inconsistent formats, unstructured HTML.
• High friction for scraping.
• Need for open APIs, standardised data formats.

B. Dependence on External Tools

• Shift from proprietary tools (Tableau) → open-source + AI pipelines.
• Greater technological sovereignty for newsrooms.

Implications for Future Elections

• AI-native election rooms become standard.
• Hybrid workflows: AI for computation, humans for interpretation.
• Increasing demand for:
  • Data journalists
  • Policy-aware technologists
  • Election-law literate analysts
• Sets the stage for predictive analysis, probabilistic modelling like U.S. outlets (538 model equivalents for India).

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South Asia’s Air Pollution Crisis

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Why Is It in News?

• North India and eastern/northern Pakistan experienced an extreme cross-border smog episode in Nov 2024, popularly termed the “2024 India–Pakistan Smog”.
• Delhi and Lahore recorded among the highest AQI readings globally, with “brown clouds” visible in satellite images.
• The episode re-opened debates on regional airshed management, cross-border pollution flows, and South Asia’s anthropogenic emissions crisis.
• Relevance renewed in 2025 as Delhi and Lahore again top global pollution charts.

Relevance

GS-1: Geography & Society

• Transboundary environmental phenomena.
• Urbanisation impacts.

GS-2: Governance

• Inter-governmental coordination, regulatory institutions (CAQM).
• Cross-border environmental diplomacy.

GS-3: Environment

• Air pollution, climate change, anthropogenic emissions.
• Reports: Greenpeace 2023, WHO AQG 2021, UNEP 2023.
• Economic impacts of pollution.

What Was the 2024 India–Pakistan Smog?

• A severe, transboundary pollution event across:
  • Eastern & northern Pakistan (esp. Lahore)
  • North India (Delhi NCR, Punjab, Haryana, UP)
• Visible as brown aerosol clouds in satellite imagery.
• Triggered by a convergence of:
  • Low wind speeds → pollutant stagnation
  • Post-harvest biomass burning across Punjab–Haryana–Punjab (Pakistan) belt
  • Industrial emissions
  • Vehicular exhaust accumulation
  • Winter inversion layers trapping pollutants
• Winds shifted from Pakistan towards Delhi, worsening Delhi’s AQI.

How Has Air Pollution Become Rampant Across South Asia?

A. Shared Meteorology

• Indo-Gangetic Plain behaves as a single airshed.
• Winter inversion + low dispersion + high humidity increases PM2.5 concentration.

B. High Anthropogenic Emissions

• Pakistan: crop-burning, brick kilns, industrial clusters near Lahore.
• India: vehicles, industries, solid fuel, construction, crop burning.
• Bangladesh: brick kilns, diesel generators, transport.
• Nepal: valley trapping effect in Kathmandu.

C. Rapid Urbanisation + Weak Governance

• Poor public transport, land-use mismanagement, unregulated construction, and old diesel fleets.

D. Climate Change Feedback Loop

• Heatwaves → increased ozone formation.
• Erratic winds → stagnant air pockets.

E. Political–Administrative Fragmentation

• No formal regional clean air treaty despite identical airshed.

What Does the Greenpeace 2023 World Air Quality Report State?

Core Findings for South Asia

• World’s most polluted region, with PM2.5 levels exceeding WHO standards by 7–10 times.
• Key drivers:
  • Industrial emissions (steel, cement, brick kilns).
  • Vehicular emissions.
  • Burning of solid fuels (biomass, crop residue, waste).
  • Coal-based power generation.
• Pakistan, India, Bangladesh, Nepal dominate list of most polluted countries/cities.
• Notes lack of coordinated regional action despite shared geography.

Economic Impact of Deteriorating AQI Levels in India

A. Direct Economic Loss

• Lancet Journal (2019): India’s GDP fell by 1.36% due to premature morbidity & mortality.
• Other estimates:
  • 3% of GDP lost due to healthcare costs + lost labour productivity.
  • India loses ~8.5 lakh lives annually from air pollution (IHME data context).

B. Labour Productivity Decline

• Fatigue, respiratory illness → lower work hours.
• Outdoor workforce (construction, transport) hit hardest.

C. Healthcare Burden

• Escalating treatment of asthma, COPD, cardiovascular diseases.

D. Impact on Investment & Tourism

• Pollution deters FDI inflow in key cities.
• Reduced tourist footfall during peak winter season.

E. Agriculture & Climate Impact

• Pollution-induced dim sunlight (global dimming) → reduced crop yields.
• Ozone exposure damages staples: wheat, rice, pulses.

Way Ahead

A. Regional Airshed Governance (Key Recommendation)

• Adopt a South Asian cross-border airshed management framework.
• Model: California’s Bay Area Air Quality Management District or ASEAN Transboundary Haze Agreement.
• IIT Bhubaneswar’s study supports “airshed-scale” governance.

B. Strengthen Domestic Governance

• Move from episodic GRAP responses → to permanent emission-reduction plans.
• Mandate 24×7 industrial monitoring, strict action on non-compliant units.

C. Sectoral Reforms

• Agriculture:
  • MSP-linked crop diversification
  • In-situ residue management (Happy seeder incentives)
• Transport:
  • Electrification
  • Bus fleet expansion
  • Non-motorised mobility
• Urban Planning:
  • Greening, heat-island mitigation, dust control
  • Construction regulation
• Energy:
  • Phase-down of coal
  • Scale rooftop solar + clean cooking fuel

D. Data, Science, Monitoring

• Real-time satellite-based emission tracking.
• Unified Air Quality Data Portal for South Asia.

E. Political Will & Social Model

• A “caring human development model” prioritising health, workers, farmers, and urban poor.

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Over 50% Cases Pending in Juvenile Justice Boards (JJBs): India Justice Report

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Why Is It in News?

• India Justice Report (IJR) released a dedicated study on capacity and performance of Juvenile Justice Boards (JJBs)—first such national-level, empirical assessment.
• Found 55% pendency, severe vacancies, weak data architecture, and institutional incapacity despite a decade of the JJ Act, 2015.
• Justice Madan B. Lokur called the findings “deeply worrying”, highlighting systemic neglect.

Relevance

• GS-2: Governance, Vulnerable Sections
  Systemic failure in delivering justice to minors.
• GS-2: Judiciary
  Pendency, quasi-judicial bodies, institutional delays.

What Are JJBs?

• Created under Juvenile Justice (Care & Protection) Act, 2015 to handle cases of Children in Conflict with Law (CICL).
• Mandated composition:
  • 1 Judicial Magistrate (First Class)
  • 2 Social Workers (at least one woman)
• Philosophy:
  • Child-friendly inquiry
  • Rehabilitation > Punishment
  • Speedy resolution (within 4 months, ideally)

Key Data (India Justice Report 2023)

Pendency

• 55% of 1,00,904 cases pending (as of Oct 31, 2023).
• State variation:
  • Odisha: 83% pendency
  • Karnataka: 35% pendency
• 154 cases pending per JJB annually on average.

Vacancies & Institutional Weakness

• 24% JJBs not fully constituted → breaks statutory requirement.
• Staff shortages in Child Care Institutions (CCIs): counsellors, probation officers, house parents.
• 30% JJBs lack Legal Services Clinics → affects access to representation.

Weak Data Governance

• No NJDG-like centralised data portal for JJBs.
• From 250+ RTI filings:
  • 11% rejected
  • 24% no response
  • 29% transferred
  • Only 36% valid responses
• Reveals poor transparency and weak record-handling culture.

Inter-agency Coordination Failures

• Weak linkage among:
  • Police → JJB
  • District Child Protection Units
  • CCIs
  • Child Welfare Committees
• Delays in Social Investigation Reports and counselling assessments.

Why the System is Failing ?

• Underfunding of juvenile justice mechanisms.
• Lack of trained personnel → high turnover of social workers.
• Weak monitoring by State Child Protection Societies.
• Policing-oriented mindset, not child-centric.
• Poor infrastructure, digitalisation, reporting.

Impact

• Delays compromise:
  • Child rehabilitation
  • Schooling, social reintegration
  • Rights under Article 21
• Prolonged detention increases:
  • Trauma
  • Risk of repeat offending
  • Institutionalisation effects

Way Forward

• Fill vacancies, professionalise cadre of social workers.
• National data grid for JJBs.
• Independent performance audits.
• Adequate funding for CCIs, mental health support.
• Mandatory training for JJB members.
• Strengthening convergence with DCPUs, CWCs, and legal aid bodies.

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Indian-born Cheetah Mukhi Gives Birth to Five Cubs – Milestone for Project Cheetah

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Why Is It in News?

• At Kuno National Park (MP), Mukhi, the first India-born female cheetah, has given birth to five cubs.
• First instance of second-generation wild breeding in India post-reintroduction.
• Raises total cheetah population to 32, including 21 India-born.
• Termed a breakthrough by Union Environment Ministry for proving ecological adaptation.

Relevance

• GS-3 (Environment & Biodiversity)
  Species reintroduction, ecological restoration.
• GS-3 (Conservation Governance)
  Role of NTCA, scientific protocols.
• GS-3 (Science & Tech)
  Animal telemetry, habitat modelling.

Project Cheetah

• Launched 2022 for reintroduction of cheetahs from Namibia & South Africa.
• Objective:
  • Establish self-sustaining, genetically diverse cheetah metapopulations.
  • Restore open forest–savannah landscapes.
• Managed by:
  • NTCA
  • WII
  • State Forest Departments

Why Mukhi’s Birth Is Historically Significant

A. First India-born cheetah to reproduce

• Establishes evidence of successful biological integration of reintroduced cheetahs.

B. Proof of suitability of Indian habitats

• Indicates:
  • Sufficient prey base
  • Acceptable predator competition
  • Healthy adaptation cycle

C. Wild reproduction despite early adversity

• Mukhi was:
  • Born to Namibian cheetah Jwala (2023)
  • Abandoned at birth
  • Hand-raised by Kuno staff
  • Later rewilded successfully
• Demonstrates adaptive success of human-assisted rearing + wild integration.

Population Update

• Total cheetahs: 32
  • 29 in Kuno
  • 3 in Gandhi Sagar Wildlife Sanctuary
• 21 are India-born → large F1 generation emerging.

Scientific and Conservation Significance

A. Genetic viability

• Second-generation births critical for:
  • Genetic mixing
  • Minimising founder-effect bottlenecks
  • Stability of future populations

B. Behavioural adaptation

• Shows:
  • Successful hunting skills
  • Reproductive acceptance
  • Habitat fidelity

C. Indicator of ecological restoration

• Cheetahs returning to Indian landscapes after 70+ years (extinct since 1952).

Challenges still present

• Mortality among translocated cheetahs.
• Kuno’s limited carrying capacity (approx. 20–21 adults).
• Need for multiple cheetah landscapes (Gandhi Sagar, Nauradehi, Mukundra Hills).
• Radio-collar issues.
• Potential human–wildlife conflict.

Way Forward

• Diversify release sites to prevent overcrowding in Kuno.
• Strengthen veterinary and monitoring teams.
• Improve prey base and grassland restoration.
• Scientific population management (genetic mapping, soft-release protocols).
• Community engagement to prevent conflict.

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Indigenous Gene Editing Tool (Birsa-101)

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 Why Is It in News?

• CSIR-IGIB (Institute of Genomics & Integrative Biology) has developed India’s first fully indigenous CRISPR-Cas9–based gene editing platform.
• Technology transferred to Serum Institute of India (SII) for Phase II–III clinical trials.
• Using this platform, IGIB developed a curative gene therapy for sickle cell disease (SCD) named Birsa-101 (after Birsa Munda, as SCD is highly prevalent among tribal communities).
• Expected to be significantly cheaper than the US-approved gene therapy Casgevy (USD 2.2 million per patient).
• Phase I trials will be conducted with AIIMS Delhi; manufacturing facility already set up.

Relevance

GS-2 (Health, Governance)

• National SCD Elimination Mission.
• Inclusive tribal health policy.

GS-3 (Science & Technology)

• Biotechnology, genetic engineering, indigenous R&D.
• CRISPR applications and ethical concerns.

GS-1 (Society)

• Tribal health challenges.
• Disease burden in vulnerable populations.

What Is Sickle Cell Disease (SCD)?

• Inherited blood disorder caused by mutation in the HBB gene → defective haemoglobin (HbS).
• Results in:
  • Rigid, sickle-shaped RBCs
  • Blocked blood vessels
  • Pain crises, anaemia, organ failure
  • Infections, stroke risk
• India’s tribal belts in MP, Chhattisgarh, Jharkhand, Odisha, Maharashtra, Gujarat have highest burden.

Basics of CRISPR-Cas9 Gene Editing

What is CRISPR-Cas9?

• A bacterial immune-system protein that acts as “genetic scissors”.
• Precisely cuts specific DNA segments → allows correction of disease-causing mutations.
• Awarded the 2020 Nobel Prize for Chemistry.

Indian Improvement

• IGIB scientists created an indigenous Cas9 variant (2016):
  • Avoids expensive Western IP.
  • Optimised for reduced off-target effects (major global concern).
  • Allows editing exactly at the mutation site (curative edit).

What Is Birsa-101 Gene Therapy?

Mechanism

• Directly corrects the defective mutation in HBB gene.
• One-time infusion of edited stem cells.
• Once corrected, the body begins producing normal haemoglobin.

How it differs from Casgevy (US therapy)

Feature	Birsa-101 (India)	Casgevy (US/UK)
Strategy	Corrects the original mutation	Increases fetal haemoglobin (HbF) to bypass defect
Technology	Indigenous CRISPR-Cas9	Licensed CRISPR tech (very expensive)
Cost	Expected to be fraction of $2.2 million	$2.2 million per patient
Long-term effect	Potential cure	Functional cure but mechanism bypasses root cause

Why Is This a Major Scientific Breakthrough?

A. Complete Indigenous Development

• All patents held by Indian scientists.
• Avoids global IP licensing → drastically lower cost → scalable for India’s tribal SCD mission.

B. Addresses a Major Public Health Challenge

• SCD affects:
  • ~1 in 86 births in certain tribal districts.
  • 10–11% carrier prevalence in many Adivasi populations.
• Aligned with National Mission to Eliminate Sickle Cell Anaemia (2023–2030).

C. Global-Standard Gene Editing Platform

• India becomes one of very few countries with:
  • Own CRISPR tool
  • Own clinical-grade manufacturing
  • Capability for gene-editing therapy trials

D. Reduced “Off-Target” Risk

• IGIB Cas9 engineered to minimise unintended edits:
  • Off-target mutations can cause cancer, developmental defects, organ damage.
  • Many global Cas9 variants unsuitable for therapy due to unpredictable cuts.

What Happens Next?

Clinical Pathway

• Phase I trials (AIIMS Delhi, 2025) → safety, dosing.
• Phase II–III trials (Serum Institute) → efficacy, scalability.
• Regulatory review by CDSCO + DBT + ICMR.
• Integration into national SCD elimination programme after approval.

Industrial Pathway

• IGIB already built GMP-grade manufacturing for clinical batches.
• SII to scale production for national deployment after Phase I.

Wider Scientific Significance

• Positions India in the global gene therapy market (currently dominated by US/EU).
• Opens doors for editing therapies for:
  • Thalassemia
  • Gaucher’s disease
  • Duchenne muscular dystrophy
  • Rare genetic disorders (India has 70M affected)
• Establishes a sovereign biotechnological ecosystem:
  • Indigenous gene-editing IP
  • Indigenous manufacturing
  • Indigenous clinical trial pipeline

Challenges Ahead

• Ensuring long-term safety (off-target monitoring for years).
• Cost reduction for mass rollout in rural tribal belts.
• Infrastructure for genetic testing, counselling, and follow-up.
• Ethical and regulatory oversight for gene editing.

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Mount Semeru Eruption

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Why is it in News?

• Mount Semeru, one of Indonesia’s most active volcanoes, erupted again on Wednesday, releasing ash clouds, pyroclastic flows, and volcanic debris.
• Located in Java, Semeru is part of the Pacific “Ring of Fire,” making it prone to frequent eruptions.
• The eruption renewed concerns over Indonesia’s high volcanic risk, evacuation readiness, and the science behind explosive eruptions.

Relevance

• GS1 (Geography): Physical geography, volcanism, tectonic processes.
• GS3 (Disaster Management): Hazard assessment, early warning, mitigation.

What causes volcanic eruptions?

• Heat inside Earth melts rocks into magma in the mantle.
• Magma is lighter than surrounding solid rock → rises through cracks.
• It accumulates in magma chambers beneath volcanoes.
• As more magma enters the chamber, pressure builds.
• When pressure > strength of the overlying rock → magma forces its way out through vents.
• Once it reaches the surface, it is called lava.

Why are some eruptions explosive and others gentle?

a) Low-viscosity magma (runny/thin) → Gentle eruptions

• Basalt-rich, low silica.
• Gases escape easily → low pressure buildup.
• Produces lava flows (e.g., Hawai’i volcanoes).

b) High-viscosity magma (thick/sticky) → Explosive eruptions

• Andesitic/rhyolitic, high silica.
• Traps gases → enormous pressure builds.
• Sudden release = explosive eruption, throwing ash, pumice, tephra.
• Produces pyroclastic flows (like Semeru).

Why Semeru is so explosive?

• High-silica magma → very viscous.
• Closed conduit system traps gases effectively.
• Located on a subduction zone (Indo-Australian plate under Eurasian plate), which naturally produces gas-rich, sticky magma.
• Generates deadly pyroclastic flows, ash columns, lahars.

Indonesia’s Volcanic Vulnerability

• Sits on the Ring of Fire with 120+ active volcanoes.
• Subduction of tectonic plates produces high-pressure volcanic systems.
• Dense population on volcanic slopes increases risks.

Overview

A. Causes of volcanic eruptions

• Mantle convection & heat → melting of rocks.
• Buoyancy of magma → upward movement.
• Gas pressure in magma chambers.
• Weak zones / fractures created by tectonic movements.

B. Types of volcanic eruptions

• Effusive (Hawaii-like) – lava flows, low danger.
• Explosive (Semeru, Krakatoa) – ash columns, pyroclastic flows.
• Phreatomagmatic – interaction with water increases explosivity.

C. Hazard profile of explosive eruptions

• Pyroclastic density currents: fastest and deadliest.
• Ash clouds: aviation risk, respiratory hazards.
• Lahars: volcanic mudflows; long-term destruction.
• Climate impacts: large eruptions can inject aerosols → global cooling.

D. Why some volcanoes erupt repeatedly

• Constant magma supply due to subduction tectonics.
• Structural weakness of volcanic conduits.
• Recharge of magma chambers over time.