Topic 6: Vulcanicity & Earthquakes in India

India sits astride one of Earth's most active collision zones — the Indian plate driving north into Eurasia — making earthquakes a first-order hazard for the Himalaya, the plains and even parts of the "stable" peninsula. This chapter builds the physics first (vulcanicity, earthquake mechanics, focus & epicentre, seismic waves, magnitude vs intensity), then applies it to India: the Deccan-Trap volcanic record, the live volcanoes of the Andaman arc (Barren & Narcondam), the BIS seismic-zone map (Zones II–V), the great Indian earthquakes (Bhuj, Latur, Kashmir, Sikkim), reservoir-induced & intraplate seismicity, the 2004 tsunami, and disaster mitigation. With labelled diagrams, tables and PYQs + full model answers.

UPSC Prelims · Mains GS-I & GS-III Seismic Zones · Bhuj · Tsunami ~40 min read Disaster Management link Very High Weight

1.India's Seismotectonic Setting — Overview
2.Vulcanicity & India's Volcanic Record
3.Present Volcanoes: Barren & Narcondam
4.Earthquake Mechanics: Focus, Waves, Magnitude
5.Why India is Earthquake-Prone
6.Seismic Zoning of India (Zones II–V)
7.Major Indian Earthquakes
8.Intraplate & Reservoir-Induced Seismicity
9.Tsunami & the 2004 Indian Ocean Event
10.Impacts, Mitigation & GS-III Synthesis
11.Current Affairs Link
12.Prelims PYQs
13.Mains PYQs + Model Answers
★15-Minute Revision Box

Conceptual Clarity — Why this Chapter Matters

This is a cross-over chapter — Prelims tests the definitions, Mains (GS-III) tests disaster management. Sort your prep three ways:

Definitional / static: focus (hypocentre) vs epicentre; body waves (P, S) vs surface waves (L); P = fastest & through solid+liquid, S = only through solids (reveals the liquid outer core); magnitude (Richter/moment, energy) vs intensity (Mercalli, damage); Barren = only active volcano.
Statement-elimination: seismic Zones II–V (V = highest risk: NE, Kashmir, Kutch, Andaman), Bhuj 2001 (intraplate, Kutch), Latur 1993 & Koyna 1967 (peninsular/reservoir-induced), 2004 tsunami source (Sumatra subduction).
Applied / synthesis (Mains GS-III): why the Himalaya & Kutch are so seismic (plate convergence), why "stable" peninsula still quakes, building-code & early-warning gaps, NDMA & the tsunami-warning system. Needs cause + example + policy.

Territorial note: the seismic zones described cover the entire sovereign territory of India, including Jammu & Kashmir, Ladakh and the Andaman & Nicobar Islands. The LoC and LAC are not settled international borders.

1. India's Seismotectonic Setting — Overview

Earthquakes and volcanoes are endogenic (internal-force) phenomena driven by plate tectonics. India's hazard profile flows from one master fact: the Indian plate is moving north-north-east at ~5 cm/yr and colliding with the Eurasian plate, building the Himalaya and storing vast crustal strain.

Convergent margin: the Indian plate underthrusts the Eurasian plate along the Himalaya — a continent–continent collision generating shallow, damaging quakes.
Subduction margin: off the Andaman–Sumatra arc the Indian plate subducts, producing volcanoes (Barren, Narcondam) and great tsunamigenic quakes (2004).
Intraplate stress: even the rigid peninsula carries ancient rift faults (Narmada–Son, Godavari) that occasionally rupture (Latur, Koyna).

Fig 6.1 — The northward-moving Indian plate underthrusts the Eurasian plate, uplifting the Himalaya and storing strain that releases as shallow, damaging earthquakes (schematic, not to scale).

One master fact: India's seismicity is a direct product of the Indian plate's northward collision. The higher the strain accumulation (Himalaya, Kutch), the higher the seismic zone.

2. Vulcanicity & India's Volcanic Record

Vulcanicity is the movement of molten rock (magma) into or onto the crust. India today has very little active volcanism on the mainland — but its geological past holds one of Earth's greatest volcanic events.

2.1 Types (quick recap)

Intrusive (plutonic): magma cools within the crust → batholiths, dykes, sills, laccoliths.
Extrusive (volcanic): lava reaches the surface → central-vent cones or, as in India, vast fissure flows.

2.2 India's volcanic record

Deccan Traps: around 66 Ma, enormous fissure eruptions of basaltic lava covered ~5 lakh km² of west-central India — one of the largest volcanic provinces on Earth; source of black regur soil and step ("trap") topography.
Rajmahal Traps: older (Jurassic–Cretaceous) basalt flows in the east (Jharkhand–Bengal).
Present-day: active volcanism is confined to the Andaman arc (Barren, Narcondam) — not the mainland.

Deccan Trap significance: fissure basalt → fertile black-cotton (regur) soil + flat-topped stepped plateaus; the eruptions coincide with the K–Pg mass extinction (a debated contributor alongside the Chicxulub impact).

3. Present Volcanoes: Barren & Narcondam

India's only volcanoes are in the Andaman Sea, on the Indian–Burmese subduction arc — an extension of the Indonesian volcanic belt.

Volcano	Status	Note
Barren Island	Active (India's only active volcano)	Andaman Sea; erupted repeatedly (incl. recent decades); uninhabited
Narcondam	Dormant	Andaman Sea; forested; Narcondam hornbill endemic

Prelims lock: Barren Island = India's ONLY active volcano, in the Andaman group (Bay of Bengal / Andaman Sea). Narcondam is dormant. Neither is on the mainland or in Lakshadweep.

4. Earthquake Mechanics: Focus, Waves & Magnitude

An earthquake is the shaking of the ground from a sudden release of accumulated crustal strain (elastic-rebound theory) — usually along a fault.

4.1 Focus & epicentre

Focus (hypocentre): the point inside the Earth where rupture begins; shallow-focus quakes are the most damaging.
Epicentre: the point on the surface directly above the focus; shaking is strongest here.

Fig 6.2 — Rupture starts at the focus underground; the point on the surface directly above is the epicentre, from which seismic waves radiate (schematic).

4.2 Seismic waves

Wave	Type	Key property
P-wave (Primary)	Body, longitudinal	Fastest; travels through solids, liquids & gases
S-wave (Secondary)	Body, transverse	Slower; travels only through solids (reveals the liquid outer core — S-wave shadow zone)
L-wave (Surface)	Surface (Love/Rayleigh)	Slowest but most destructive; confined to the surface

4.3 Magnitude vs intensity

Magnitude = energy released; measured on the Richter / moment-magnitude scale (logarithmic) — a single value per quake.
Intensity = degree of shaking/damage felt; measured on the Modified Mercalli scale — varies with distance & ground.

Prelims lock: P-waves are fastest and pass through liquids; S-waves cannot pass liquids (proving the liquid outer core). Magnitude (Richter) = energy; intensity (Mercalli) = felt damage.

5. Why India is Earthquake-Prone

About 59% of India's land is prone to moderate-to-severe earthquakes — a consequence of active tectonics on three fronts.

Himalayan collision belt: continuous strain from the plate collision → frequent shallow quakes (Uttarkashi 1991, Kashmir 2005, Nepal 2015 felt across N. India).
Kutch & western margin: ancient rift & the Kutch fault system → great intraplate quakes (Bhuj 2001).
Andaman–Nicobar subduction: plate subduction → volcanoes & tsunamigenic mega-quakes (2004).
Peninsular rift faults: Narmada–Son, Godavari, Koyna → occasional damaging intraplate/reservoir-induced quakes (Latur 1993, Koyna 1967).
Soft-soil amplification: the thick alluvium of the plains amplifies shaking, raising damage far from the epicentre.

Key idea: the more strain a region stores (Himalaya, Kutch) or the softer its ground (Gangetic alluvium), the greater its earthquake risk — which is exactly what the seismic-zone map encodes.

6. Seismic Zoning of India (Zones II–V)

The Bureau of Indian Standards (BIS) divides India into four seismic zones — II, III, IV and V (an older map had five; Zone I was merged into II) — in rising order of expected intensity. There is no Zone I today.

Zone	Risk	Representative areas
Zone V	Very high (highest)	NE India, Kashmir–Himalaya, Kutch (Gujarat), N. Bihar, Andaman & Nicobar
Zone IV	High	Delhi-NCR, remaining Himalayan foothills, parts of Indo-Gangetic plain, Sikkim
Zone III	Moderate	Much of the peninsula fringe, central India, coastal belts
Zone II	Low	Most of the stable peninsular interior

Zone V (most dangerous): the entire NE, Kashmir Himalaya, the Kutch (Rann) region, parts of north Bihar and the Andaman & Nicobar Islands.
Delhi lies in Zone IV — a high-risk mega-city on soft Yamuna alluvium.
The zoning is based on past seismicity, tectonics and expected ground motion — it drives the earthquake-resistant building codes (IS 1893).

Prelims lock: India has four seismic zones (II–V); Zone V is the highest risk (NE, Kashmir, Kutch, N. Bihar, A&N); there is no Zone I. Delhi = Zone IV.

7. Major Indian Earthquakes

A handful of quakes recur in exams — learn the year, place, tectonic type and one lesson for each.

Earthquake	Year	Type / setting	Lesson
Assam–Tibet	1950	Himalayan collision (great quake, M~8.6)	Brahmaputra course changes; NE hazard
Koyna	1967	Peninsular — reservoir-induced	Dams can trigger quakes (RIS)
Uttarkashi	1991	Himalayan (Uttarakhand)	Hill building vulnerability
Latur (Killari)	1993	Peninsular intraplate (Maharashtra)	"Stable" shield can rupture; heavy toll
Bhuj	2001	Intraplate, Kutch fault (Gujarat)	Great intraplate quake; building codes overhauled
Kashmir (Muzaffarabad)	2005	Himalayan collision	Cross-border relief; landslides
Sikkim	2011	Himalayan	NE Zone-V risk to hydropower
Nepal (Gorkha)	2015	Himalayan collision	Felt across N. India; regional exposure

Bhuj 2001 (Republic Day) was a great intraplate quake on the Kutch fault — a wake-up call that led to strengthened building codes, the Gujarat State Disaster Management Authority and, nationally, momentum toward the Disaster Management Act, 2005 and the NDMA.

8. Intraplate & Reservoir-Induced Seismicity

Most quakes occur at plate boundaries, but India also suffers intraplate quakes deep inside the "stable" peninsula, and human-triggered reservoir-induced seismicity.

Intraplate seismicity: reactivation of ancient rift faults (Narmada–Son, Godavari) — e.g. Latur 1993 — rare but shallow and destructive because they strike unprepared regions.
Reservoir-induced seismicity (RIS): the weight of a large reservoir + water seepage lubricating faults can trigger quakes — the classic case is Koyna 1967 (Maharashtra), one of the world's best-documented RIS events.

Why it matters: intraplate & RIS quakes show that "stable" is relative — peninsular dams, cities and industry are not risk-free. This links directly to disaster-management planning for large reservoirs (Tehri, Sardar Sarovar).

9. Tsunami & the 2004 Indian Ocean Event

A tsunami is a series of long-wavelength sea waves generated by the sudden vertical displacement of the sea floor — usually by a submarine subduction earthquake (also by undersea landslides or volcanic collapse).

2004 Indian Ocean tsunami: triggered by a great (M~9.1) subduction quake off Sumatra; devastated the Andaman & Nicobar Islands and the Tamil Nadu–Andhra–Kerala coasts.
Why coasts are exposed: low, flat, densely-settled east coast (Coromandel) and the near-source A&N islands took the worst impact.
Response: India set up the Indian Tsunami Early Warning Centre (ITEWC) at INCOIS, Hyderabad, plus coastal bio-shields (mangroves) and preparedness drills.

Prelims & Mains hook: tsunamis come from subduction quakes (vertical sea-floor movement), not from every earthquake. The 2004 source was the Sumatra subduction zone; India's warning system is run by INCOIS/ITEWC.

10. Impacts, Mitigation & GS-III Synthesis

Earthquakes cannot be predicted or prevented — so the entire strategy is risk reduction: know the hazard, build for it, and prepare communities.

Structural mitigation: earthquake-resistant design (IS 1893, IS 13920), retrofitting, ductile detailing, enforcing building bye-laws — especially in Zones IV–V.
Non-structural: microzonation of cities (Delhi, Guwahati), land-use control on soft soils, insurance, and public awareness/mock drills.
Institutional: the Disaster Management Act, 2005 and NDMA (with SDMAs/DDMAs); NDRF for response; early-warning for tsunamis (INCOIS).
Ecological: mangrove/coral "bio-shields" reduce tsunami & surge energy on the coast.

GS-III synthesis: India's seismicity is fixed by tectonics, but its disaster risk is a policy variable — enforcement of building codes, microzonation, retrofitting and community preparedness decide whether a quake becomes a catastrophe. The single logic: hazard is natural; disaster is man-made — mitigation, not prediction, saves lives.

11. Current Affairs & Contemporary Relevance (2024–2026)

Seismic risk stays "current" through Himalayan quakes, dam-safety debates, microzonation and warning-system upgrades — verify the latest status. check for latest update or data

11.1 Himalayan & regional seismicity

Recurring Himalayan quakes: moderate tremors along the Himalayan arc and in the NE keep the "great Himalayan earthquake" risk and the fragility of hill hydropower (Joshimath subsidence, 2023) in the news. check for latest update or data

11.2 Dam safety & RIS

Dam Safety Act, 2021: renewed focus on reservoir-induced seismicity and ageing-dam safety (Koyna, Tehri) ties this chapter to live infrastructure-risk policy. check for latest update or data

11.3 Warning & preparedness

Microzonation & early warning: seismic microzonation of major cities and upgrades to the INCOIS tsunami-warning system recur in disaster-management news. check for latest update or data

11.4 Why it matters

Development	Why it matters for UPSC
Joshimath subsidence / hill hazards	Himalayan fragility & disaster link (GS-I & GS-III).
Dam Safety Act, 2021	Reservoir-induced seismicity & ageing dams.
City microzonation	Urban earthquake risk (Delhi Zone IV).
INCOIS tsunami warning	Coastal preparedness after 2004.

Recurring exam hooks:

Focus/epicentre · P/S/L waves · magnitude vs intensity (evergreen Prelims).
Seismic zones · Barren volcano · Bhuj/Latur/Koyna (favourite factual sets).
Disaster mitigation, NDMA, building codes, tsunami warning (evergreen Mains GS-III).

12. Prelims PYQs (exam-style, high-frequency themes)

Objective questions anchored to genuinely tested UPSC themes on vulcanicity, earthquakes and seismic zoning in India. Each carries a worked rationale.

UPSC Prelims — exam-style

Q: The point on the Earth's surface directly above the focus of an earthquake is called the:

(a) Epicentre
(b) Hypocentre
(c) Fault scarp
(d) Isoseismal

Answer: (a) Epicentre. The focus (hypocentre) is the underground rupture point; the epicentre is directly above it on the surface, where shaking is strongest.

UPSC Prelims — exam-style

Q: Which seismic waves cannot pass through the liquid outer core, thereby proving its liquid state?

(a) P-waves
(b) S-waves
(c) L-waves
(d) Rayleigh waves

Answer: (b) S-waves (transverse) cannot travel through liquids — the resulting S-wave shadow zone proves the outer core is liquid. P-waves (fastest) pass through solids and liquids.

UPSC Prelims — exam-style

Q: India's only active volcano is:

(a) Narcondam
(b) Barren Island
(c) Dhinodhar
(d) Baratang mud volcano

Answer: (b) Barren Island (Andaman Sea) is India's only active volcano. Narcondam is dormant; Baratang has mud volcanoes (not true lava volcanoes).

UPSC Prelims — exam-style

Q: How many seismic zones does the current BIS map divide India into?

(a) Three
(b) Four (II, III, IV, V)
(c) Five (I–V)
(d) Six

Answer: (b) Four zones (II–V); the erstwhile Zone I was merged into Zone II, so there is no Zone I. Zone V is the highest risk.

UPSC Prelims — exam-style

Q: Consider the following statements about seismic Zone V:

1. It is the highest-risk zone.
2. The Kutch region of Gujarat lies in it.
3. Most of the peninsular interior falls in it.

Which are correct?

(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

Answer: (a) 1 and 2 only. Zone V is highest-risk and includes Kutch, NE India, Kashmir Himalaya, N. Bihar & A&N. The stable peninsular interior is mostly Zone II (low), not V.

UPSC Prelims — exam-style

Q: The Koyna earthquake (1967) is a classic example of:

(a) A plate-boundary collision quake
(b) Reservoir-induced seismicity
(c) A volcanic earthquake
(d) A subduction-zone tsunami quake

Answer: (b) Koyna is one of the world's best-documented cases of reservoir-induced seismicity — the reservoir's load and water seepage triggered fault movement in the peninsula.

UPSC Prelims — exam-style

Q: The 2004 Indian Ocean tsunami was generated by a great earthquake off the coast of:

(a) Sri Lanka
(b) Sumatra (Indonesia)
(c) the Makran coast
(d) the Andaman ridge only

Answer: (b) The M~9.1 subduction quake off Sumatra triggered the tsunami that struck the A&N Islands and India's east coast. Tsunamis need vertical sea-floor displacement, typical of subduction quakes.

UPSC Prelims — exam-style

Q: Which pair is correctly matched (earthquake — setting)?

(a) Latur 1993 — Himalayan collision
(b) Bhuj 2001 — intraplate (Kutch fault)
(c) Koyna 1967 — subduction zone
(d) Kashmir 2005 — reservoir-induced

Answer: (b) Bhuj 2001 was a great intraplate quake on the Kutch fault. Latur = peninsular intraplate; Koyna = reservoir-induced; Kashmir 2005 = Himalayan collision.

Prelims — anticipated themes

Likely: focus vs epicentre · P/S/L waves & shadow zones · magnitude (Richter) vs intensity (Mercalli) · four seismic zones & Zone-V areas · Barren active volcano · Deccan/Rajmahal traps · Bhuj/Latur/Koyna settings · RIS · 2004 tsunami source & INCOIS · ~59% of India seismic. check for latest update or data

13. Mains PYQs + Model Answers

Genuine UPSC GS-I/GS-III themes on India's seismicity, vulcanicity and disaster management. Each carries a full answer skeleton — Introduction → body → Conclusion.

UPSC Mains GS-I — style 15 marks · 250 words

Q: Explain why India is highly prone to earthquakes and how the seismic-zone map reflects this.

Model Answer

Introduction: nearly 59% of India is quake-prone — a direct result of the Indian plate's northward collision with Eurasia.
Causes: the Himalayan collision belt (shallow quakes), the Kutch rift (Bhuj), Andaman subduction (tsunamigenic quakes), peninsular rift faults (Latur, Koyna) and soft-soil amplification in the plains.
Zone map: BIS Zones II–V grade this risk — Zone V (NE, Kashmir, Kutch, N. Bihar, A&N) is highest, Zone II the peninsular interior; the map drives building codes.
Implication: high-risk zones coincide with dense settlement (Himalayan towns, Delhi, Kutch), so exposure is severe.
Conclusion: the zone map translates tectonics into planning — making enforcement of zone-based codes the key to cutting risk.

UPSC Mains GS-III — style 15 marks · 250 words

Q: "Earthquakes cannot be predicted, but disasters can be prevented." Discuss with reference to India's mitigation framework.

Model Answer

Introduction: seismic prediction remains scientifically elusive, so India's strategy centres on risk reduction, not forecasting.
Structural mitigation: earthquake-resistant design (IS 1893/13920), retrofitting of schools/hospitals, and enforcement of building bye-laws in Zones IV–V.
Non-structural: city microzonation, land-use control on soft soils, insurance and community mock-drills.
Institutional: the Disaster Management Act 2005, NDMA/SDMA/DDMA, NDRF for response, and INCOIS tsunami early-warning — much of it catalysed by Bhuj 2001 and the 2004 tsunami.
Conclusion: the hazard is fixed by nature but the disaster is shaped by preparedness — enforcement and awareness, not prediction, save lives.

UPSC Mains GS-I — style 15 marks · 250 words

Q: Although the Peninsular Plateau is considered stable, it is not free from seismic activity. Examine.

Model Answer

Introduction: the peninsula is an ancient rigid shield, generally aseismic — yet it has produced damaging quakes, showing "stable" is relative.
Intraplate faults: ancient rift zones (Narmada–Son, Godavari) can reactivate — Latur 1993 struck an unprepared shield region with heavy casualties.
Reservoir-induced: large dams add load and pore-pressure that can trigger quakes — Koyna 1967 is a global reference case.
Consequence: because these areas assumed safety, buildings were unprepared, magnifying damage — a lesson for peninsular cities & dams.
Conclusion: intraplate and reservoir-induced seismicity mean the whole country, not just the Himalaya, needs seismic-safe construction.

UPSC Mains GS-III — style 15 marks · 250 words

Q: Discuss the causes and consequences of tsunamis in the Indian context, with reference to the 2004 event.

Model Answer

Introduction: tsunamis are long sea waves from sudden vertical sea-floor displacement, usually by great subduction earthquakes.
2004 causes: an M~9.1 subduction quake off Sumatra uplifted the sea floor, sending waves across the Indian Ocean.
Consequences for India: the near-source A&N Islands and the low, densely-settled Tamil Nadu–Andhra coasts suffered massive loss of life and property.
Response & lessons: India built the INCOIS/ITEWC warning centre, promoted mangrove bio-shields, coastal zoning and preparedness drills.
Conclusion: tsunami risk is concentrated on subduction-facing coasts — early warning, ecological buffers and coastal planning are the core defences.

UPSC Mains GS-I — style 10 marks · 150 words

Q: Bring out the significance of the Deccan Trap volcanism in India's physical geography.

Model Answer

Introduction: around 66 Ma, vast fissure eruptions built the Deccan Trap, one of Earth's largest volcanic provinces.
Soils: weathered basalt yields fertile, moisture-retentive black regur — the base of the cotton belt.
Relief: horizontal lava sheets created the flat-topped, step-like ("trap") plateaus and Ghat escarpments.
Conclusion: a single volcanic episode still shapes India's soils, relief and agriculture across a sixth of the country.

Mains — anticipated themes

Likely: why India is quake-prone & the zone map · prediction vs mitigation (NDMA) · peninsular/intraplate & RIS seismicity · tsunami causes & 2004 · Deccan Trap significance · Himalayan hill-hazard & hydropower risk. check for latest update or data

15-Minute Revision Box

Must-Remember Facts — Vulcanicity & Earthquakes

Mechanics:

Focus = underground rupture; Epicentre = surface point above
P-wave = fastest, through solid+liquid; S-wave = solids only (liquid-core proof)
L-wave = surface, most destructive
Magnitude (Richter) = energy; Intensity (Mercalli) = damage

Vulcanicity:

Deccan Trap ~66 Ma fissure basalt → regur soil
Rajmahal Traps (older, east)
Barren = only active volcano; Narcondam dormant

Seismic zones:

Four zones II–V (no Zone I); V = highest
Zone V = NE, Kashmir, Kutch, N. Bihar, A&N
Delhi = Zone IV; ~59% of India seismic

Major quakes & tsunami:

Bhuj 2001 = intraplate (Kutch) → DM Act 2005/NDMA
Latur 1993 = peninsular intraplate
Koyna 1967 = reservoir-induced (RIS)
2004 tsunami = Sumatra subduction; INCOIS warning

Highest-frequency themes: focus/epicentre · P/S waves & core · magnitude vs intensity · four zones & Zone-V areas · Barren volcano · Bhuj/Latur/Koyna types · 2004 tsunami source & INCOIS. One logic: India's seismicity = plate collision; risk = strain stored + soft soil; disaster = policy failure, so mitigation (codes, microzonation, warning) not prediction saves lives.

Wave	Key trait
P	Fastest; solid+liquid
S	Solids only
L	Surface; destructive

Zone	Risk
V	Very high (NE, Kutch)
IV	High (Delhi)
III	Moderate
II	Low (peninsula)

Topic 6: Vulcanicity & Earthquakes in India

On this page

Conceptual Clarity — Why this Chapter Matters

1. India's Seismotectonic Setting — Overview

2. Vulcanicity & India's Volcanic Record

2.1 Types (quick recap)

2.2 India's volcanic record

3. Present Volcanoes: Barren & Narcondam

4. Earthquake Mechanics: Focus, Waves & Magnitude

4.1 Focus & epicentre

4.2 Seismic waves

4.3 Magnitude vs intensity

5. Why India is Earthquake-Prone

6. Seismic Zoning of India (Zones II–V)

7. Major Indian Earthquakes

8. Intraplate & Reservoir-Induced Seismicity

9. Tsunami & the 2004 Indian Ocean Event

10. Impacts, Mitigation & GS-III Synthesis

11. Current Affairs & Contemporary Relevance (2024–2026)

11.1 Himalayan & regional seismicity

11.2 Dam safety & RIS

11.3 Warning & preparedness

11.4 Why it matters

12. Prelims PYQs (exam-style, high-frequency themes)

13. Mains PYQs + Model Answers

Model Answer

Model Answer

Model Answer

Model Answer

Model Answer

15-Minute Revision Box

Must-Remember Facts — Vulcanicity & Earthquakes