Earthquake Zones of India — Seismic Zones, Major Earthquakes, and NDMA Guidelines

India is highly vulnerable to earthquakes — about 59% of India’s land area is prone to moderate to very high intensity earthquakes. Understanding seismic zones, past earthquakes, and disaster preparedness is essential for PSC exams.

1. Why India is Earthquake-Prone

Factor	Explanation
Indian Plate movement	The Indian Plate moves northward at about 5 cm/year and collides with the Eurasian Plate
Himalayan seismic belt	The collision zone produces intense seismic activity along the entire Himalayan arc
Intraplate seismicity	Peninsular India also experiences earthquakes due to ancient fault lines (e.g., Bhuj 2001)
Subduction zones	Andaman-Nicobar region lies on a subduction zone (Indo-Australian Plate under Burma Plate)

2. India’s Seismic Zones (BIS: IS 1893:2002)

India is divided into 4 seismic zones (Zone II to V). Zone I was merged with Zone II in 2002.

Zone	Intensity (MSK)	Risk Level	Major Areas Covered
Zone V	IX and above	Very High	Entire northeast India, parts of J and K, Himachal Pradesh, Uttarakhand, Kutch (Gujarat), Andaman and Nicobar Islands
Zone IV	VIII	High	Remaining parts of J and K, Himachal, parts of UP, Bihar, parts of Delhi-NCR, northern Punjab, parts of Maharashtra near Latur
Zone III	VII	Moderate	Kerala, Goa, remaining Maharashtra, parts of Punjab, Rajasthan, MP, Jharkhand, Chhattisgarh, parts of West Bengal
Zone II	VI and below	Low	Remaining parts of peninsular India — most of Tamil Nadu, Karnataka interior, Andhra Pradesh interior, Rajasthan desert

PSC Favourite: “How many seismic zones does India have currently?” — 4 zones (Zone II to V). Zone I was merged with Zone II after the 2001 Bhuj earthquake revision.

Kerala Note: Kerala falls primarily in Zone III (moderate risk). However, the Idukki reservoir area has experienced reservoir-induced seismicity.

3. Major Earthquakes in India

Year	Location	Magnitude	Casualties	Key Facts
1819	Kutch (Rann of Kutch), Gujarat	8.0	~1,500	Created the “Allah Bund” (natural dam)
1897	Shillong, Assam	8.1	~1,542	One of the first well-documented Indian earthquakes
1905	Kangra, Himachal Pradesh	7.8	~20,000	Devastated Kangra Valley
1934	Bihar-Nepal	8.1	~10,700	Massive destruction in Muzaffarpur, Darbhanga
1950	Assam-Tibet border	8.6	~1,530	One of the largest recorded earthquakes globally
1967	Koyna, Maharashtra	6.3	177	Reservoir-induced seismicity (Koyna Dam); strongest in peninsular India at the time
1988	Bihar-Nepal border	6.6	~1,004	—
1991	Uttarkashi, Uttarakhand	6.8	~768	—
1993	Latur (Killari), Maharashtra	6.2	~9,748	Struck a zone considered “safe” (then Zone I); led to revision of seismic zone map
1999	Chamoli, Uttarakhand	6.8	~103	—
2001	Bhuj, Gujarat	7.7	~20,000	Republic Day earthquake (26 Jan); massive destruction in Kutch; led to revision of IS 1893 in 2002
2004	Indian Ocean (Sumatra)	9.1	~12,000+ in India	Triggered the devastating tsunami; worst in Andaman-Nicobar, Tamil Nadu coast
2005	Kashmir	7.6	~1,300+ in India (73,000 in Pakistan)	—
2011	Sikkim	6.9	~111	—
2015	Nepal (felt strongly in India)	7.8	~9,000 (Nepal); ~78 in India	Bihar, UP, West Bengal affected
2023	Joshimath subsidence	—	Land subsidence, not earthquake	Related to tectonic vulnerability of the area

4. Earthquake Measurement Scales

Scale	Measures	Range	Key Point
Richter Scale	Magnitude (energy released)	0-10 (logarithmic)	Each whole number = 10x amplitude, ~31.6x energy
Modified Mercalli Scale (MMI)	Intensity (felt effects)	I-XII	Based on observed damage; varies by location
MSK Scale	Intensity	I-XII	Used in India’s seismic zonation
Moment Magnitude Scale (Mw)	Magnitude	Open-ended	Most accurate for large earthquakes; now the global standard

5. NDMA (National Disaster Management Authority)

Aspect	Detail
Established under	Disaster Management Act, 2005
Chairman	Prime Minister of India
Maximum members	9 (including chairperson)
Role	Plans, policies, and guidelines for disaster management across India
State-level body	SDMA (State Disaster Management Authority), headed by the Chief Minister
District-level body	DDMA (District Disaster Management Authority), headed by the Collector
NDRF	National Disaster Response Force — specialised response force under NDMA

NDMA Guidelines for Earthquake Preparedness

Guideline	Detail
Earthquake-resistant construction	Mandatory in Zones III, IV, and V
Retrofitting old buildings	Government buildings, schools, and hospitals to be prioritised
Awareness programmes	School drills, community awareness, mock drills
Early warning systems	Seismological network of India (operated by IMD and NCS)
Land-use planning	No critical infrastructure in high-risk zones near fault lines

6. Building Codes — BIS Standards

Standard	Purpose
IS 1893 (Part 1): 2016	Criteria for earthquake-resistant design of structures (general provisions)
IS 4326: 2013	Earthquake-resistant design and construction of buildings
IS 13920: 2016	Ductile detailing of reinforced concrete structures
IS 13935: 2009	Repair and seismic strengthening of buildings

Feature	Detail
Seismic zone factor (Z)	Zone II: 0.10, Zone III: 0.16, Zone IV: 0.24, Zone V: 0.36
Base isolation	Advanced technique to isolate building from ground shaking
Soft storey	Ground floor with open parking is a major vulnerability; requires special design
Non-structural elements	Parapets, water tanks, and cladding must be secured

7. Key Organisations

Organisation	Role
IMD (India Meteorological Department)	Monitors seismic activity; operates seismological observatories
NCS (National Centre for Seismology)	Under MoES; India’s nodal agency for earthquake monitoring
GSI (Geological Survey of India)	Geological mapping and seismic hazard assessment
NDMA	Policy and guidelines for disaster management
NDRF	Operational rescue and response during disasters
NIDM (National Institute of Disaster Management)	Training and capacity building
BIS (Bureau of Indian Standards)	Issues building codes and standards

8. Earthquake Terminology for PSC

Term	Meaning
Focus (Hypocentre)	Point underground where the earthquake originates
Epicentre	Point on the surface directly above the focus
Seismograph	Instrument that records earthquake waves
P-waves	Primary waves — fastest, travel through solids and liquids
S-waves	Secondary waves — slower, travel only through solids
Surface waves	Slowest but most destructive
Aftershock	Smaller earthquake following the main shock
Foreshock	Smaller earthquake preceding the main shock
Liquefaction	Soil behaves like liquid during shaking; common in sandy/wet areas
Tsunami	Ocean wave caused by underwater earthquake (magnitude usually 7.0+)

9. Previous Year PSC-Style Questions

Question	Answer
How many seismic zones does India have?	4 (Zone II to V)
Which is the highest seismic risk zone?	Zone V
The 2001 Bhuj earthquake occurred on which date?	26 January 2001 (Republic Day)
Koyna earthquake (1967) was caused by?	Reservoir-induced seismicity
NDMA is headed by?	Prime Minister
The Richter Scale measures?	Magnitude of an earthquake
Kerala falls in which seismic zone?	Zone III
What was the Latur earthquake’s significance?	Struck a zone previously classified as Zone I (safe); led to revision of seismic zones
The instrument used to measure earthquakes is?	Seismograph
NDRF stands for?	National Disaster Response Force