{"id":342964,"date":"2025-07-17T17:30:04","date_gmt":"2025-07-17T12:00:04","guid":{"rendered":"https:\/\/forumias.com\/blog\/?p=342964"},"modified":"2025-12-11T10:18:47","modified_gmt":"2025-12-11T04:48:47","slug":"earthquakes-mechanism-distribution-preparedness-explained-pointwise","status":"publish","type":"post","link":"https:\/\/forumias.com\/blog\/earthquakes-mechanism-distribution-preparedness-explained-pointwise\/","title":{"rendered":"Earthquakes &#8211; Mechanism, Distribution &#038; Preparedness &#8211; Explained Pointwise"},"content":{"rendered":"<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">Recently, several earthquake tremors were felt in the National Capital Region as reported by National Centre for Seismology. Increased frequency of such tremors is a wake up call for India&#8217;s seismic vulnerability &amp; particularly highlights the vulnerability of Delhi which currently houses 33.5mn people &amp; over 5,000 high rise buildings, where over 80% buildings, fail to comply with seismic codes.<\/span><\/p>\n<table style=\"border-collapse: collapse; width: 100%; height: 180px;\">\n<tbody>\n<tr style=\"height: 30px;\">\n<td style=\"width: 100%; text-align: center; height: 30px;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Table of Content<\/strong><\/span><\/td>\n<\/tr>\n<tr style=\"height: 150px;\">\n<td style=\"width: 100%; height: 150px;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><a href=\"#h1\">What is an EARTHQUAKE?<\/a><\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><a href=\"#h2\">EARTHQUAKE WAVES<\/a><\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><a href=\"#h3\">TYPES OF FAULTS ASSOSCIATED WITH EARTHQUAKES<\/a><\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><a href=\"#h4\">TYPES OF EARTHQUAKES<\/a><\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><a href=\"#h5\">MEASURING EARTHQUAKES<\/a><\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><a href=\"#h6\">DISTRIBUTION OF EARTHQUAKE<\/a><\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><a href=\"#h7\">SEISMIC VULNERABILITY OF INDIA<\/a><\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><a href=\"#h8\">EARTHQUAKE ZONES IN INDIA<\/a><\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><a href=\"#h9\">WHAT PREPAREDNESS MEASURES HAVE BEEN UNDERTAKEN?<\/a><\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><a href=\"#h10\">WAY FORWARD<\/a><\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2><span style=\"text-decoration: underline; font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong><a id=\"h1\"><\/a>What is an EARTHQUAKE?<\/strong><\/span><\/h2>\n<ul>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">An earthquake (also known as a quake, tremor or temblor) is a type of diastrophic movement which involves shaking of the Earth surface, resulting from the sudden release of energy in the Earth&#8217;s lithosphere that creates seismic waves.<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">The release of energy occurs along a fault. A fault is a sharp break in the crustal rocks. Rocks along a fault tend to move in opposite directions. As the overlying rock strata press them, the friction locks them together. However, their tendency to move apart at some point of time overcomes the friction. As a result, the blocks get deformed and eventually, they slide past one another abruptly. This causes a release of energy, and the energy waves travel in all directions.<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">The point inside the earth where the energy is released is called the <strong>FOCUS<\/strong> (also known as the <strong>HYPOCENTER<\/strong>)<strong>.<\/strong> The point on the surface, nearest to the focus, is called <strong>EPICENTRE.<\/strong><\/span><\/li>\n<\/ul>\n<h2><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong><span style=\"text-decoration: underline;\"><a id=\"h2\"><\/a>EARTHQUAKE WAVES<\/span>:<\/strong><\/span><\/h2>\n<ul>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">Earthquake shaking and damage is the result of 2 basic types of seismic waves:<\/span>\n<ol>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Body Waves =<\/strong> Travel through the <strong data-start=\"192\" data-end=\"217\">interior of the Earth<\/strong>.:<\/span>\n<ol style=\"list-style-type: lower-alpha;\">\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>P-waves =\u00a0<\/strong>Longitudinal (compressional) waves<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>S-waves =\u00a0<\/strong>Transverse (shear) waves<\/span><\/li>\n<\/ol>\n<\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Surface Waves =<\/strong> Travel along the <strong data-start=\"955\" data-end=\"974\">Earth\u2019s surface<\/strong> (cause most destruction):<\/span>\n<ol style=\"list-style-type: lower-alpha;\">\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>L-waves =\u00a0<\/strong>Horizontal shear motion (side-to-side)<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>R-waves =\u00a0<\/strong>Rolling motion (like ocean waves) \u2013 both vertical and horizontal<\/span><\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>P-waves<\/strong> = The faster of these body waves is called the primary or P wave. Its motion is the same as that of a sound wave in that, as it spreads out, it alternately pushes (compresses) and pulls (dilates) the rock. These P waves are able to travel through both solid rock, such as granite mountains, and liquid material, such as volcanic magma or the water of the oceans.<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>S-waves =<\/strong> The slower wave through the body of rock is called the secondary or S wave. As an S wave propagates, it shears the rock sideways at right angles to the direction of travel. If a liquid is sheared sideways or twisted, it will not spring back, hence S waves cannot propagate in the liquid parts of the earth, such as oceans and lakes.<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>L-waves<\/strong> i.e. <strong>Love waves<\/strong> = Its motion is essentially that of S waves that have no vertical displacement; it moves the ground from side to side in a horizontal plane but at right angles to the direction of propagation. The horizontal shaking of Love waves is particularly damaging to the foundations of structures.<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>R-waves<\/strong> i.e. <strong>Rayleigh waves = <\/strong>They are like rolling ocean waves. Rayleigh waves move both vertically and horizontally in a vertical plane pointed in the direction in which the waves are travelling.<\/span><\/li>\n<\/ul>\n<h2><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong><span style=\"text-decoration: underline;\"><a id=\"h3\"><\/a>TYPES OF FAULTS ASSOCIATED WITH EARTHQUAKES<\/span>:<\/strong><\/span><\/h2>\n<ul>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">There are 3 main types of faults: <strong>Normal, Reverse<\/strong> (Thrust) and <strong>Strike-slip<\/strong>.<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">Normal and reverse faulting are examples of dip-slip, where the displacement along the fault is in the direction of dip and movement on them involves a vertical component.<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Normal faults<\/strong> occur mainly in areas where the crust is being extended such as a divergent boundary.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Reverse faults<\/strong> occur in areas where the crust is being shortened such as at a convergent boundary.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Strike-slip faults<\/strong> are steep structures where the two sides of the fault slip horizontally past each other. Transform boundaries are a particular type of strike-slip fault.<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">Reverse faults, particularly those along convergent plate boundaries are associated with the most powerful earthquakes, megathrust earthquakes, including almost all of those of magnitude 8 or more.<\/span><\/li>\n<\/ul>\n<h2><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong><span style=\"text-decoration: underline;\"><a id=\"h4\"><\/a>TYPES OF EARTHQUAKES<\/span>:<\/strong><\/span><\/h2>\n<table style=\"width: 100%; border-collapse: collapse; background-color: #eef09c;\">\n<tbody>\n<tr>\n<td style=\"width: 13.1483%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Shallow-Focus Earthquakes<\/strong><\/span><\/td>\n<td style=\"width: 86.8517%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Depth:<\/strong> 0 \u2013 70 km<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Occurrence:<\/strong> Most common type (~80% of all earthquakes).<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Impact:<\/strong> Most destructive because the energy is released close to the Earth\u2019s surface.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Examples:<\/strong> Nepal earthquake (2015), Bhuj earthquake (2001).<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 13.1483%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Intermediate-Focus Earthquakes<\/strong><\/span><\/td>\n<td style=\"width: 86.8517%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Depth:<\/strong> 70 \u2013 300 km<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Occurrence:<\/strong> About 12% of earthquakes.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Impact:<\/strong> Less destructive than shallow-focus but can still cause significant damage over a wide area.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Examples:<\/strong> Earthquakes in subduction zones (e.g., Peru-Chile Trench).<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 13.1483%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Deep-Focus Earthquakes<\/strong><\/span><\/td>\n<td style=\"width: 86.8517%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Depth:<\/strong> 300 \u2013 700 km<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Occurrence:<\/strong> About 3% of earthquakes.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Impact:<\/strong> Rarely cause surface destruction due to great depth, but can be very powerful.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Examples:<\/strong> Earthquakes in the Tonga Trench and Mariana Trench regions.<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong><span style=\"text-decoration: underline;\"><a id=\"h5\"><\/a>MEASURING EARTHQUAKES<\/span>:<\/strong><\/span><\/h2>\n<table style=\"width: 100%; border-collapse: collapse; background-color: #f0fa93;\">\n<tbody>\n<tr>\n<td style=\"width: 7.41583%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Magnitude<\/strong><\/span><\/td>\n<td style=\"width: 92.5842%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">The <strong data-start=\"4\" data-end=\"34\">magnitude of an earthquake<\/strong> refers to the <strong data-start=\"49\" data-end=\"117\">amount of energy released at the earthquake\u2019s focus (hypocentre)<\/strong> during seismic activity.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">It is a quantitative measure, usually expressed on a <strong data-start=\"196\" data-end=\"217\">logarithmic scale.<br \/>\n<\/strong>It is measured by using <strong data-start=\"196\" data-end=\"217\">RICHTER SCALE.<br \/>\n<\/strong>The magnitude is expressed in absolute numbers, 0-10.<strong data-start=\"196\" data-end=\"217\"><br \/>\n<\/strong><\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 7.41583%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Intensity<\/strong><\/span><\/td>\n<td style=\"width: 92.5842%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">The <strong data-start=\"4\" data-end=\"34\">intensity of an earthquake<\/strong> refers to the <strong data-start=\"49\" data-end=\"156\">measure of the effects and damage caused by the earthquake at specific locations on the Earth&#8217;s surface<\/strong>. The intensity scale takes into account the visible damage caused by the event.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">Intensity is a qualitative measure of the shaking at a given location.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">Two scales most commonly used for intensity are the <strong>Modified Mercalli Intensity scale<\/strong> and <strong>MSK scale<\/strong>, both of which classify earthquakes from I (least perceptible) to XII (most severe). These readings are based on factors such as how people perceive the shaking. The same earthquake will have different intensity readings at different places; the farther one moves away from the epicentre, the less intense the shaking.<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2><span style=\"text-decoration: underline; font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong><a id=\"h6\"><\/a>DISTRIBUTION OF EARTHQUAKE:<\/strong><\/span><\/h2>\n<table style=\"width: 100%; border-collapse: collapse; background-color: #e8f0a3;\">\n<tbody>\n<tr>\n<td style=\"width: 13.7398%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Circum-Pacific Belt (Ring of Fire)<\/strong><\/span><\/td>\n<td style=\"width: 86.2603%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Location:<\/strong> Surrounds the Pacific Ocean (Japan, Indonesia, Philippines, Chile, Alaska, California).<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Share:<\/strong> ~70\u201380% of the world\u2019s earthquakes.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Cause:<\/strong> Subduction zones and transform faults.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 13.7398%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Alpine\u2013Himalayan Belt<\/strong><\/span><\/td>\n<td style=\"width: 86.2603%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Location:<\/strong> From the Mediterranean \u2192 Middle East \u2192 Himalayas \u2192 Southeast Asia.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Share:<\/strong> ~15\u201320% of earthquakes.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Cause:<\/strong> Collision between Eurasian Plate and African\/Indian Plates.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 13.7398%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Mid-Atlantic Ridge (Oceanic Ridges)<\/strong><\/span><\/td>\n<td style=\"width: 86.2603%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Location:<\/strong> Runs down the Atlantic Ocean; includes Iceland.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Cause:<\/strong> Divergent plate boundaries (sea-floor spreading).<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Earthquake type:<\/strong> Mostly shallow-focus.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 13.7398%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Intraplate Earthquakes<\/strong><\/span><\/td>\n<td style=\"width: 86.2603%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">Occur within tectonic plates, away from boundaries.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">Examples: New Madrid Seismic Zone (USA), Kutch Region (India)<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2><span style=\"color: #000000; font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong><u><a id=\"h7\" style=\"color: #000000;\"><\/a>SEISMIC VULNERABILITY OF INDIA:<\/u><\/strong><\/span><\/h2>\n<ul>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">Around <strong data-start=\"1881\" data-end=\"1908\">58% of India\u2019s landmass<\/strong> is vulnerable to moderate or severe seismic hazard.<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">India&#8217;s seismic risk is rooted in the northward drift of the Indian Plate, colliding with the Eurasian Plate at 4-5cm a year.<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Great Himalayan Earthquake<\/strong> = Himalayas are one of the most tectonically active regions of the world. An earthquake of magnitude 8 or higher is long overdue in the region according to various seismic studies. The Himalayan <strong>&#8216;Seismic Gap&#8217;\u00a0<\/strong>where strain has built since the Kangra earthquake (1906) &amp; Gorkha earthquake (2015), are a ticking clock.<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">Factors Increasing Vulnerability:<\/span>\n<ul>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">Unplanned urbanization and poor construction practices.<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">High population density in hazard-prone regions.<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">Lack of earthquake-resistant design in many buildings.<\/span><\/li>\n<li><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">Low awareness and preparedness.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2><span style=\"text-decoration: underline; font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong><a id=\"h8\"><\/a>EARTHQUAKE ZONES IN INDIA:<\/strong><\/span><\/h2>\n<table style=\"width: 100%; border-collapse: collapse; background-color: #e4f067;\">\n<tbody>\n<tr>\n<td style=\"width: 12.6024%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Zone 5<\/strong><\/span><\/td>\n<td style=\"width: 87.3976%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">Zone 5 covers the areas with the highest risk zone that suffers earthquakes of intensity MSK IX or greater.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">It is referred to as the <strong>Very High Damage Risk Zone<\/strong>.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">The region 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.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 12.6024%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Zone 4<\/strong><\/span><\/td>\n<td style=\"width: 87.3976%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">This zone is called the <strong>High Damage Risk Zone<\/strong> and covers areas liable to MSK VIII.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Sikkim, parts of Indo-Gangetic plains (North Punjab, Chandigarh, Western Uttar Pradesh, Terai, North Bengal, Sundarbans) and the capital of the country Delhi fall in Zone 4. In Maharashtra, the Patan area (Koynanagar) is also in Zone 4. In Bihar the northern part of the state like Raxaul, near the border of India and Nepal, is also in Zone 4.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 12.6024%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Zone 3<\/strong><\/span><\/td>\n<td style=\"width: 87.3976%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">This zone is classified as <strong>Moderate Damage Risk Zone<\/strong> which is liable to MSK VII.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">Zone 3 = Gujarat, Goa, West Bengal, parts of Andhra, Tamil Nadu<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 12.6024%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Zone 2<\/strong><\/span><\/td>\n<td style=\"width: 87.3976%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">This region is liable to MSK VI or less and is classified as the <strong>Low Damage Risk Zone<\/strong>.<\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">Zone 2 = Southern Deccan Plateau, Karnataka, Kerala<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">Since the current division of India into earthquake hazard zones does not use Zone 1, no area of India is classed as Zone 1.<\/span><\/p>\n<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-342976 size-full\" src=\"https:\/\/i0.wp.com\/forumias.com\/blog\/wp-content\/uploads\/2025\/07\/ndian-seismic-zone-map-of-2002.png?resize=600%2C600&#038;ssl=1\" alt=\"\" width=\"600\" height=\"600\" srcset=\"https:\/\/i0.wp.com\/forumias.com\/blog\/wp-content\/uploads\/2025\/07\/ndian-seismic-zone-map-of-2002.png?w=600&amp;ssl=1 600w, https:\/\/i0.wp.com\/forumias.com\/blog\/wp-content\/uploads\/2025\/07\/ndian-seismic-zone-map-of-2002.png?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/forumias.com\/blog\/wp-content\/uploads\/2025\/07\/ndian-seismic-zone-map-of-2002.png?resize=150%2C150&amp;ssl=1 150w\" sizes=\"auto, (max-width: 600px) 100vw, 600px\" \/><\/span><\/p>\n<h2><span style=\"text-decoration: underline; font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong><a id=\"h9\"><\/a>WHAT PREPAREDNESS MEASURES HAVE BEEN UNDERTAKEN?<\/strong><\/span><\/h2>\n<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><b><span class=\"citation-96\">1. Seismic Zoning Map:<\/span><\/b><span class=\"citation-96 citation-end-96\"> The Bureau of Indian Standards (BIS) has classified India into four seismic zones (Zone II, III, IV, and V) based on historical earthquake data and geological features.<\/span> This map guides earthquake-resistant design. <span class=\"citation-95 citation-end-95\">Zone V is the most seismically active, while Zone II is the least.<\/span><\/span><\/p>\n<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><b><span class=\"citation-94\">2. Earthquake-Resistant Building Codes:<\/span><\/b><span class=\"citation-94 citation-end-94\"> The National Building Code of India includes stringent guidelines for designing earthquake-resistant structures, especially in high-risk zones.<\/span><\/span><\/p>\n<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><b><span class=\"citation-93\">3. Retrofitting of Buildings:<\/span><\/b><span class=\"citation-93 citation-end-93\"> A major focus has been on retrofitting and strengthening existing older buildings, particularly critical infrastructure (hospitals, schools, government buildings) and those in highly vulnerable areas, to withstand seismic events.<\/span> Financial grants are sanctioned to support these efforts.<\/span><\/p>\n<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><b><span class=\"citation-91\">4. Expansion of Seismic Observatories:<\/span><\/b><span class=\"citation-91 citation-end-91\"> The number of seismic observatories has significantly increased (from 80 in 2014 to 168 by February 2025), enhancing monitoring capabilities.<\/span><\/span><\/p>\n<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><b><span class=\"citation-89\">5. BhooKamp App:<\/span><\/b><span class=\"citation-89 citation-end-89\"> Launched by NCS, this mobile application provides real-time earthquake information to users.<\/span><\/span><\/p>\n<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><b>6. Earthquake Risk Indexing (EDRI):<\/b> NDMA&#8217;s EDRI project assesses earthquake risks in Indian cities, evaluating hazard, vulnerability, and exposure to guide mitigation efforts. Phase I covered 50 cities, and Phase II targets 16 more.<\/span><\/p>\n<h2><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong><span style=\"text-decoration: underline;\"><a id=\"h10\"><\/a>WAY FORWARD<\/span>:<\/strong><\/span><\/h2>\n<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><b><span class=\"citation-118\">1. Strict Compliance and Audits:<\/span><\/b><span class=\"citation-118 citation-end-118\"> Implement stricter enforcement mechanisms for existing earthquake-resistant building codes (e.g., IS 1893:2016) for all new constructions.<\/span> This includes mandatory structural safety certificates and regular, independent structural audits, especially for critical infrastructure, schools, hospitals, and high-rise buildings.<\/span><\/p>\n<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><b><span class=\"citation-117\">2. Retrofitting Old Structures:<\/span><\/b><span class=\"citation-117 citation-end-117\"> Accelerate and expand the retrofitting program for the vast inventory of older, non-compliant buildings, particularly in high-risk seismic zones and densely populated urban centers.<\/span> This will require significant budgetary allocation, government incentives, and public-private partnerships.<\/span><\/p>\n<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><b>3. Risk-Informed Urban Planning:<\/b><span class=\"citation-116 citation-end-116\"> Enforce stringent land-use regulations to avoid construction in high-risk liquefaction zones and active fault lines.<\/span> Promote urban planning that includes adequate open spaces for evacuation and resilient infrastructure development.<\/span><\/p>\n<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><b>4. Accelerate EEW System Deployment:<\/b><span class=\"citation-115 citation-end-115\"> Expedite the research, development, and deployment of robust Earthquake Early Warning (EEW) systems, particularly in the Himalayan region and other Zone IV and V areas.<\/span> Focus on &#8220;last-mile connectivity&#8221; to ensure timely alerts reach communities effectively.<\/span><\/p>\n<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><b>5. International Collaboration:<\/b> Strengthen collaboration with earthquake-prone countries (e.g., Japan, Chile) to share best practices, research, and technology in earthquake monitoring and early warning systems.<\/span><\/p>\n<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><b>6. Continuous Awareness Campaigns:<\/b> Sustain and intensify public awareness campaigns using diverse media to educate citizens on earthquake risks, safe building practices, and the &#8220;Drop, Cover, and Hold On&#8221; technique.<\/span><\/p>\n<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><b>7. Seismic Insurance and Risk Financing:<\/b><span class=\"citation-113 citation-end-113\"> Explore and promote government-backed earthquake insurance schemes for homes and businesses, potentially with incentives for adopting earthquake-resistant measures, to transfer financial risk and aid faster recovery.\u00a0<\/span><\/span><\/p>\n<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Conclusion:<\/strong><\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\">The seismic activity intensifying globally as well as regionally, from Greece to Indonesia to Chile-Argentina border &amp; Ecuador signals a dynamic earth. India cannot afford delay &amp; must bridge the enforcement gap to prevent large-scale devastation.<\/span><\/p>\n<table style=\"border-collapse: collapse; width: 100%;\">\n<tbody>\n<tr>\n<td style=\"width: 100%;\"><span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>Read More: <a href=\"https:\/\/www.thehindu.com\/opinion\/op-ed\/a-tectonic-shift-in-thinking-to-build-seismic-resilience\/article69820061.ece\" target=\"_blank\" rel=\"noopener\">The Hindu<\/a>, <a href=\"https:\/\/en.wikipedia.org\/wiki\/Earthquake\" target=\"_blank\" rel=\"noopener\">Wikipedia<\/a><\/strong><\/span><br \/>\n<span style=\"font-family: arial, helvetica, sans-serif; font-size: 14pt;\"><strong>USPC GS-1: Geography\u00a0<\/strong><\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"excerpt":{"rendered":"<p>Recently, several earthquake tremors were felt in the National Capital Region as reported by National Centre for Seismology. Increased frequency of such tremors is a wake up call for India&#8217;s seismic vulnerability &amp; particularly highlights the vulnerability of Delhi which currently houses 33.5mn people &amp; over 5,000 high rise buildings, where over 80% buildings, fail&hellip; <a class=\"more-link\" href=\"https:\/\/forumias.com\/blog\/earthquakes-mechanism-distribution-preparedness-explained-pointwise\/\">Continue reading <span class=\"screen-reader-text\">Earthquakes &#8211; Mechanism, Distribution &#038; Preparedness &#8211; Explained Pointwise<\/span><\/a><\/p>\n","protected":false},"author":10391,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"footnotes":""},"categories":[130],"tags":[],"class_list":["post-342964","post","type-post","status-publish","format-standard","hentry","category-7-pm","entry"],"jetpack_featured_media_url":"","views":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/posts\/342964","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/users\/10391"}],"replies":[{"embeddable":true,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/comments?post=342964"}],"version-history":[{"count":0,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/posts\/342964\/revisions"}],"wp:attachment":[{"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/media?parent=342964"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/categories?post=342964"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/tags?post=342964"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}