Pressure belts and winds

  1. The Earth’s atmosphere is divided into distinct pressure belts due to uneven heating of its surface.
  2. There are seven pressure belts around the Earth: Equatorial low, Subtropical highs (two), Subpolar lows (two), and Polar highs (two).
  3. The Equatorial low-pressure belt, or the doldrums, lies around the equator (0°-5° latitude).
  4. This region experiences intense solar heating, causing air to rise and creating low pressure.
  5. The Subtropical high-pressure belts are located aroun

Weather and climate

  1. Weather refers to the short-term atmospheric conditions of a specific place at a specific time.
  2. Climate is the average weather pattern of a region over a long period, typically 30 years or more.
  3. Weather elements include temperature, humidity, precipitation, wind, and atmospheric pressure.
  4. Climate factors include latitude, altitude, proximity to water bodies, and ocean currents.
  5. Weather is highly variable and can change within hours or days.
  6. Climate

Atmosphere

  1. The atmosphere is a mixture of gases surrounding the Earth, essential for sustaining life.
  2. It consists of 78% nitrogen, 21% oxygen, and 1% other gases, including argon, carbon dioxide, and trace gases.
  3. The atmosphere is divided into five layers based on temperature variations.
  4. Troposphere: The lowest layer, where most weather phenomena occur and life exists.
  5. The average height of the troposphere is about 12 km, but it va

Major geomorphic features

  1. Geomorphic features are landforms created by internal and external forces shaping the Earth's surface.
  2. These features are classified into primary (endogenic) and secondary (exogenic) landforms.
  3. Primary landforms are formed by tectonic activities like mountain building, volcanism, and faulting.
  4. Mountains: Elevated landforms created by tectonic forces, classified as fold, block, volcanic, or residual mountains.
  5. Fold mountains: Formed by compressional force

External processes

  1. External processes are geomorphic activities that originate from forces outside the Earth's surface.
  2. These processes are also called exogenic processes.
  3. They include weathering, erosion, transportation, and deposition.
  4. External processes are driven by solar energy, gravity, and the hydrological cycle.
  5. Weathering is the breakdown of rocks into smaller particles through physical, chemical, or biological means.
  6. Physical weat

Solar system

  1. The Solar System consists of the Sun, eight planets, moons, dwarf planets, asteroids, comets, and other celestial objects.
  2. The Sun is the center of the Solar System and accounts for 99.86% of its total mass.
  3. The eight planets are classified as terrestrial planets (Mercury, Venus, Earth, Mars) and gas giants (Jupiter, Saturn) and ice giants (Uranus, Neptune).
  4. Mercury is the closest planet to the Sun and has no atmosphere to retain heat.
  5. Venus

Earth's motions

  1. The Earth has two primary motions: rotation and revolution.
  2. Rotation refers to the Earth spinning on its axis.
  3. The Earth completes one rotation in approximately 24 hours, causing day and night.
  4. The axis of rotation is tilted at an angle of 23.5° relative to the plane of its orbit.
  5. Revolution refers to the Earth's orbit around the Sun.
  6. One complete revolution takes approximately 365.25 days, leading to the concept of a year.

Structure of the Earth

  1. The Earth is divided into three main layers: the core, mantle, and crust.
  2. The crust is the Earth's outermost layer, comprising solid rocks and minerals.
  3. The thickness of the crust varies from 5 km under oceans to 70 km under continents.
  4. The crust is divided into the continental crust and oceanic crust.
  5. The continental crust is primarily composed of granite, while the oceanic crust is made of basa

Origin of the Earth

  1. The Earth is a part of the Solar System, which includes the Sun, eight planets, and other celestial bodies.
  2. The Big Bang Theory explains the origin of the universe approximately 13.8 billion years ago.
  3. The Solar System is believed to have formed about 4.6 billion years ago.
  4. The nebular hypothesis proposed by Immanuel Kant and Pierre-Simon Laplace suggests the Solar System formed from a rotating cloud of gas and dust.
  5. The protostar at the center of the nebula eventually b

Modern Developments

  1. The adoption of the Constitution of India in 1950 established India as a sovereign, secular, socialist, democratic republic.
  2. The Green Revolution (1960s–1970s) transformed India’s agriculture, achieving self-sufficiency in food grains.
  3. The White Revolution, spearheaded by Verghese Kurien, made India the largest producer of milk and dairy products.
  4. India’s space program, led by ISRO, achieved significant milestones, including the