generated during the maximum considered earthquake ground motion in that zone. Each zone indicates the effects of an earthquake at a particular place based on the observations of the affected areas and can also be described using a descriptive scale like the Modified Mercalli intensity scale or the Medvedev–Sponheuer–Karnik scale. Zone 5 Zone 5 covers the areas with the highest risk of suffering earthquakes of intensity MSK IX or more significantly. The IS code assigns a zone factor of 0.36 for Zone 5. Structural designers use this factor for the earthquake-resistant design of structures in Zone 5. The zone factor of 0.36 (the maximum horizontal acceleration that a structure can experience) is indicative of effective (zero period) level earthquakes in this zone. It is referred to as the Very High Damage Risk Zone. The regions of Kashmir, the Western and Central Himalayas, North and Middle Bihar, the North-East Indian region, the Rann of Kutch and the Andaman and Nicobar group of islands fall in this zone. Generally, the areas having trap rock or basaltic rock are prone to earthquakes. Zone 4 This zone is called the High Damage Risk Zone and covers areas liable to MSK VIII. The IS code assigns a zone factor of 0.24 for Zone 4. Jammu and Kashmir, Ladakh, Himachal Pradesh, Uttarakhand, Sikkim, parts of the Indo-Gangetic plains (North Punjab, Chandigarh, Western Uttar Pradesh, Terai, a major portion of Bihar, North Bengal, the Sundarbans) and the capital of the country Delhi fall in Zone 4. In Maharashtra, the Patan area (Koynanagar) is also in Zone 4. Zone 3 This zone is classified as a Moderate Damage Risk Zone which is liable to MSK VII. The IS code assigns a zone factor of 0.16 for Zone 3. Several megacities like Chennai, Mumbai, Bengaluru,Kolkata and Bhubaneshwar lie in this zone. Zone 2 This region is liable to MSK VI or lower and is classified as the Low Damage Risk Zone. The IS code assigns a zone factor of 0.10 for Zone 2. It is the zone with low chances of having earthquakes. Cities like Trichy or Thiruchirappalli are in this zone ,ex- cities of Bulandshahr , Moradabad, Gorakhpur, Chandigarh Zone 1 Since the current division of India into earthquake hazard zones does not use Zone 1, no area of India is classed as Zone 1. See also List of earthquakes in India Geology of India Notes Further reading