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GS Paper: GS1-14.Important Geophysical phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone etc.,

  • Landslides: The Need for Early Warning Systems

    Why in the News?

    Recent landslides across the Western Ghats and other parts of India have revived the debate on installing early warning systems (EWS) for landslides. The renewed discussion exposes a gap between what landslide-prediction technology has already proven capable of and the absence of any single, scaled system deploying it nationally.

    Why has landslide prediction returned to the policy conversation, and does the science actually work?

    1. Trigger: Recent landslides in the Western Ghats and other parts of India reignited discussion on installing EWS for such events.
    2. Proven feasibility: Landslides can be predicted in high-risk zones. The 2024 Wayanad landslide killed more than 300 people, illustrating the human cost when prediction is absent.
    3. Working precedent: Two weeks before the Wayanad disaster, landslides in Munnar caused no fatalities. The Idukki district administration evacuated residents on the advice of an Amrita University research team, led by Maneesha Vinodini Ramesh, that was testing an EWS.
    4. Global validation: EWS already operates effectively in multiple countries, establishing that the underlying approach is proven rather than experimental.

    What are the two competing methodologies India is currently developing for landslide early warning?

    1. Amrita University approach: Deploys a network of on-site sensors, tilt meters, pressure gauges, accelerometers, at high-risk slopes to measure vibration and ground movement.
    2. Threshold-based alerts: When sensor readings cross well-defined thresholds, an automated warning is issued, allowing the administration to act.
    3. IIT Mandi approach: Professor Dericks Praise Shukla’s team uses probabilistic forecasting instead of physical sensors, currently being validated against ongoing landslide events in the Himalayan region.
    4. Satellite-based mapping: The IIT Mandi team has mapped vulnerable spots across the Himalayan region using a satellite-based database of past landslide events.
    5. Multi-factor modelling: The probabilistic model factors in localised rainfall forecasts along with soil conditions, rock stability, extent of slope, and population density.

    Why does neither current methodology, on its own, deliver a complete early warning solution?

    1. Sensor method’s blind spot: Amrita’s sensor network reports data only for the specific slope where instruments are installed. Neighbouring slopes remain unmonitored, even though landslides are highly localised events.
    2. Rainfall model’s lead-time constraint: Shukla’s probabilistic model depends on rainfall forecasts, but highly localised forecasts are currently available only for the day of the event or one day earlier, giving very little lead time.
    3. Trade-off exposed: The sensor method provides adequate lead time but incomplete geographic coverage. The probabilistic method provides wider coverage but insufficient lead time.
    4. Scale limitation: Both methods remain validated only at pilot or regional scale. Neither is currently integrated into a single nationwide operational system.

    What must change before India moves from pilot-scale projects to a comprehensive national system?

    1. Precondition 1: high-risk zone identification: A comprehensive system first requires identifying high-risk areas where landslides are frequent, before sensors or models can be meaningfully deployed at scale.
    2. Risk zones already flagged: Shukla identifies the north-western Himalayan region and parts of Manipur and Mizoram as highly vulnerable. Sikkim is relatively less vulnerable due to a less dense road network, which implies greater slope stability.
    3. Precondition 2: higher-resolution rainfall forecasting: The probabilistic method’s lead-time limitation can only be resolved once the India Meteorological Department develops higher-resolution rainfall forecasts, which is currently in progress.
    4. Timeline and resourcing: A comprehensive and effective landslide EWS can be built in about two years if resources and effort are properly dedicated to it, according to Shukla.
    5. Sequencing: The stated roadmap identifies high-risk zones nationally first, and installs sensors at selected sites only afterward, mapping precedes instrumentation, not the reverse.

    Conclusion

    Landslide early warning technology is scientifically proven and has already prevented casualties in India, as seen in Munnar in 2024. No standardised national system exists, however; current efforts are split between a sensor-based method and a rainfall-probability-based method, each constrained by a different limitation, localised coverage in one case, short lead time in the other. Scaling to a comprehensive national system depends on two preconditions currently absent: systematic identification of high-risk zones across India, and higher-resolution rainfall forecasting infrastructure from the India Meteorological Department. Until both are in place, early warning capability will remain confined to isolated pilot projects rather than a nationwide shield.

    PYQ Relevance

    [UPSC 2021] Describe the various causes and the effects of landslides. Mention the important components of the National Landslide Risk Management Strategy.

    Linkage: The PYQ examines India’s institutional approach to landslide risk reduction through the National Landslide Risk Management Strategy (NLRMS) and disaster preparedness. The article directly complements this PYQ by highlighting early warning systems, sensor networks, vulnerability mapping, localized rainfall forecasting, and timely evacuation, all of which are core components of proactive landslide risk management envisaged under the NLRMS.

  • Behind Europe’s heatwave, cliamte change the culprit

    Why in the News?

    A World Weather Attribution (WWA) study has confirmed climate change as the unequivocal cause of the ongoing European heatwave, which has broken or is forecast to break historic heat-stress records in 45% of 854 cities analysed. The finding sharpens a wider gap between the certainty climate science now offers and the declining political priority accorded to climate action.

    What does the WWA study establish about the causal role of climate change in the current heatwave?

    1. Unequivocal attribution: WWA found climate change, not the El Niño phenomenon or any other factor, responsible for the European heatwave.
    2. Recurrence pattern: This is the third severe heatwave to grip Europe in five years, after 2022 and 2023.
    3. Mortality scale: More than 1,300 excess deaths have been recorded since 21 June; over 1,00,000 people are estimated to have died from extreme heat across 2022 and 2023.
    4. Probability shift: Record-breaking night-time highs are nearly 100 times more likely now than in 2003; daytime peak temperatures are nearly 10 times more likely.
    5. Historical baseline broken: Temperature records being broken were set in 1976; the current daytime and overnight highs would have been virtually impossible to occur as recently as 1976.
    6. ENSO ruled out: The El Niño Southern Oscillation phase played no role in driving the heat during this spell.

    Why has climate attribution science become central to fixing responsibility for extreme weather events?

    1. Definition: Climate attribution is the scientific discipline that determines how much human-caused global warming influences the probability and intensity of specific extreme weather events. It quantifies how much worse or more likely a particular flood, heatwave, or drought has become compared to a hypothetical world without human-driven emissions
    2. Function: Attribution science tests the likelihood of a specific extreme weather event occurring if climate change were not taking place.
    3. Recency: The discipline has developed only over the last two decades.
    4. Speed gain: Assessments earlier took months or years; WWA’s methods now produce findings within days, even while an event is still ongoing.
    5. Purpose: The science removes ambiguity and fixes the exact extent of climate change’s responsibility for an event.
    6. Scientific caution without it: Scientists are otherwise wary of linking any individual extreme weather event to climate change without a dedicated attribution study.
    7. Policy intent: Beyond generating evidence, attribution studies are designed to force policymakers to act faster on climate change.

    Does scientific certainty on climate attribution translate into proportionate political action?

    1. Evidence-action gap: Scientific evidence on climate change is already voluminous and compelling, yet climate change has dropped down the list of global priorities.
    2. Political trigger: The decline has sharpened particularly after Donald Trump took office as US President.
    3. Forum evidence: Recent G7 meetings have carried little or no climate-related agenda or outcomes.
    4. Reversal of salience: Climate change was earlier among the most prominent items at international meetings involving influential leaders; this prominence has receded.
    5. Target abandonment: Scientists maintain the Paris Agreement targets of containing global temperature rise within 1.5°C to 2°C remain achievable, but governments treat them as effectively out of reach.
    6. Reframing of feasibility: Governments are treating the required resource mobilisation as politically impractical rather than scientifically unattainable.

    What risk does the global shift from mitigation to adaptation pose?

    1. Strategic shift: Countries are increasingly choosing to let climate change play out and to adapt to its impacts rather than prevent it.
    2. Scientific objection: Scientists routinely warn against adaptation as a substitute for mitigation.
    3. Inherent limits: Adaptation has limits beyond which impacts cannot be absorbed.
    4. Trend trajectory: Events such as the European heatwave are projected to increase in both frequency and intensity over coming years.
    5. Displacement, not resolution: The shift to adaptation transfers the climate risk from prevention to adaptation capacity rather than resolving it.

    Conclusion

    Climate attribution science has removed the scientific ambiguity once used to avoid linking individual extreme weather events to climate change. The European heatwave attribution exposes a widening gap between scientific certainty and political will, as global climate governance deprioritises mitigation. Countries are substituting adaptation for prevention despite scientists’ warnings that adaptation carries inherent limits. Closing this evidence-action gap is now central to achieving the Paris Agreement targets.

    PYQ Relevance

    [UPSC 2017] ‘Climate Change’ is a global problem. How India will be affected by climate change? How Himalayan and coastal states of India will be affected by climate change?

    Linkage: The PYQ xamines the impacts of climate change and the need for mitigation and adaptation strategies. The article uses the European heatwave as scientific evidence that climate change is intensifying extreme weather events and highlights the growing gap between climate science and political action.

  • Venezuela Earthquake

    Why in News?

    A powerful doublet earthquake (Magnitude 7.2 followed by 7.5) struck Venezuela, killing over 188 people and injuring more than 1,500. It is the strongest earthquake to hit Venezuela in 126 years.

    Key Highlights

    • Two major earthquakes struck within one minute, making it a doublet earthquake.
    • Epicentres were located west of Caracas, near the coastal town of Morón.
    • Tremors were felt in Colombia and Brazil.
    • The earthquakes occurred at shallow depths (10 km and 22 km), resulting in severe ground shaking.
    • International humanitarian assistance was offered by India, the United States, the United Nations, China, Brazil, and others.

    Why Did the Earthquake Occur?

    • Plate Boundary: Venezuela lies along the boundary between the Caribbean Plate and the South American Plate.
    • Strike-slip Faulting: The Caribbean Plate moves eastward relative to the South American Plate, causing horizontal movement along faults.
    • Active Fault Zone: The earthquake occurred near the El Pilar Fault System, one of the most active fault systems in northern Venezuela.
    • Shallow-focus Earthquake: Shallow earthquakes release energy close to the Earth’s surface, leading to greater destruction.
    • Doublet Earthquake: Two large earthquakes occurring almost simultaneously amplify structural damage.

    Prelims Pointers

    • Earthquake: Sudden release of energy in the Earth’s crust due to movement along faults.
    • Focus (Hypocentre): Point inside the Earth where an earthquake originates.
    • Epicentre: Point on the Earth’s surface directly above the focus.
    • Shallow-focus earthquakes: Depth less than 70 km; generally cause maximum damage.
    • Strike-slip fault: Fault where two blocks move horizontally past each other.
    • Doublet earthquake: Two major earthquakes of similar magnitude occurring close together in time and location.

    [2023] Consider the following statements :
    1. In a seismograph, P waves are recorded earlier than S waves.
    2. In P waves, the individual particles vibrate to and fro in the direction of wave propagation whereas in S waves, the particles vibrate up and down at right angles to the direction of wave propagation.
    Which of the statements given above is/are correct?

    [A] 1 only

    [B] 2 only

    [C] Both 1 and 2

    [D] Neither 1 nor 2