upsc notes

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    Hypsometric and Mathematical Analysis

    Imagine standing on the peak of Mount Everest, looking down at the vast land below. Now, picture yourself at the bottom of the Mariana Trench, the deepest part of the ocean. These two measurements—height above sea level and depth below sea level—are fundamental in understanding Earth’s surface. This is where hypsometry and bathymetry come into…

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    Indian Ocean

    Let’s now understand the Indian Ocean, the third-largest ocean on Earth. Unlike the vast Pacific or the expanding Atlantic, the Indian Ocean has its own unique identity—a warm, enclosed ocean bound by Asia to the north, Africa to the west, and Australia to the east. It serves as a crucial link between continents, shaping monsoon…

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    Atlantic Ocean

    Introduction Let’s now talk about the Atlantic Ocean, the second-largest ocean on Earth. Picture an enormous S-shaped water body stretching between the Americas on one side and Europe & Africa on the other. This distinct shape is not just a coincidence—it is a geological fingerprint that tells a fascinating story of how continents were once…

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    Introduction to Ocean Bottom Relief

    The ocean floor, covering nearly three-fourths of the Earth’s surface, exhibits diverse and complex relief features, rivalling those found on land. Unlike the earlier belief that ocean bottoms are vast, featureless plains, modern studies reveal distinct topographical variations shaped by tectonic, volcanic, erosional, and depositional processes. The ocean floor is broadly classified into four major…

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    Trewartha’s Climate Classification

    Suppose you are on a journey, starting at the sweltering equator, moving through lush forests, dry deserts, temperate lands, and finally, reaching the icy poles. This is precisely how G.T. Trewartha classified the world’s climates—using temperature and precipitation as the guiding factors, but with a simplified approach compared to Koeppen and Thornthwaite. Unlike Koeppen, who…

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    Thornthwaite’s Climatic Classification

    Thornthwaite’s climatic classification is more complex and empirical compared to Köppen’s, incorporating evaporation, precipitation efficiency, and potential evapotranspiration (PE) to define climate types. Thornthwaite’s Climatic Classification: A Hydrological Perspective Thornthwaite’s approach introduced a new way of classifying climate, focusing not only on temperature and precipitation but also on evaporation and water balance, making it particularly…

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    Köppen’s Climatic Classification

    Whenever we study climate in geography, one question arises: how do we divide the Earth into meaningful climatic zones? Because climate is not just about temperature or rainfall alone. It affects vegetation, agriculture, lifestyle, even settlement patterns. Now, among all climatologists, Vladimir Köppen — a Russian–German scientist — stands out. His classification is so successful…

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    Understanding Climate Classification

    Suppose you are embarking on a journey across the planet, moving from the lush Amazon rainforest to the icy deserts of Antarctica. As you traverse these diverse landscapes, you’ll notice a striking pattern—each region has a unique climate that influences its vegetation, wildlife, and even human settlements. To make sense of this vast diversity, climatologists…

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    Tornadoes

    Imagine standing in an open field when the sky turns an eerie shade of green. Dark clouds swirl above, and suddenly, a towering column of spinning wind descends from the heavens, touching the ground with destructive force—a tornado is born! Tornadoes are among the most violent weather phenomena on Earth. Their winds can exceed 500…

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    Thunderstorms

    General Characteristics Imagine a hot summer afternoon. The ground is burning, the air feels heavy, and suddenly you see tall, black clouds building up in the sky. Within a short while, rain pours down furiously, thunder roars, and lightning flashes. This is what we call a thunderstorm. Technically, a thunderstorm is a local storm that…