Earthquake Zones of India 👉 Seismic Zonation Map India has released a Seismic Zonation Map under the updated Earthquake Design Code (BIS, 2025). The classification is based on faults, maximum likely events, attenuation, tectonics, lithology, and other geological parameters. Details of New Zonation India’s Earthquake Vulnerability Implications of New Map Earthquakes in Delhi–NCR Region 👉…
Distribution of Earthquakes – Global Pattern Earthquakes are not scattered randomly across the globe. They are concentrated in certain belts, which largely coincide with the margins of tectonic plates. In fact, when you plot earthquake epicentres on a world map, they clearly outline the boundaries of plates. 1. The Circum-Pacific Belt (Ring of Fire) 👉…
An earthquake is nothing but the shaking or trembling of the earth’s surface.But the question is—why does the earth shake? It happens because of seismic waves (also called earthquake waves). These waves are generated when there is a sudden movement or sudden release of energy in the earth’s crust or upper mantle. 👉 If the…
We are dealing with the classification of mountains, and mountains can be classified on three bases: 1. Classification Based on the Period of Origin Mountains are not formed in a single event. Instead, they are the results of orogenic movements (mountain-building movements) that have taken place in Earth’s history. Till now, nine major orogenies have…
When we talk about cyclones, most people immediately think of storms, winds, and destruction. But the atmosphere has another equally important system—anticyclones. Unlike cyclones, which are associated with violent weather, anticyclones are often linked with calm, stable conditions. That is why they are sometimes called “weatherless phenomena.” Let us understand their nature: General Characteristics Key…
Cyclones are not just “storms.” They are multi-hazard systems that combine: The damage potential increases with intensity. Let’s try to understand this: Damage Classification by Cyclone Intensity Category Damage Expected Measures Required Depression / Deep Depression Minor damage to weak/unsecured structures. Fishermen advised not to venture into the sea. Cyclone Damage to thatched huts, breaking…
Tropical cyclones do not form everywhere in the tropics. Instead, they are largely confined to 5°–15° latitudes in both hemispheres, over warm ocean waters. From there, they affect the coastal regions of continents. Broadly, there are six major cyclone-prone regions of the world: Now let’s look at each basin in detail. 1. North Atlantic Ocean…
This section brings us to some of the more advanced and fascinating concepts in cyclone dynamics: twin cyclones, the Fujiwhara effect, hybrid cyclones, and the Madden-Julian Oscillation (MJO). These are not only high-value for UPSC (both Prelims & Mains) but also help you appreciate how global circulation patterns interact with local weather phenomena. Let’s understand…
Cyclones are thermal-origin systems, born over warm tropical seas.They develop through successive stages, each marked by rising wind speeds, increasing organization, and eventually the formation of the eye and eyewall. Stages of Development of Tropical Cyclone Stage 1: Tropical Disturbance 👉 Think of this stage as the seed of a cyclone — scattered storms beginning…
One important point before we begin:👉 Even today, scientists don’t fully agree on a single “universal” theory of how tropical cyclones originate. But we do understand the broad conditions necessary for their birth. Earlier, some geographers supported the Frontal Theory – the idea that cyclones form due to frontogenesis (meeting of contrasting air masses). They…
