World Geography Some Glimpses Class 8 Notes SST Part 2 Chapter 1

Experts have designed these Class 8 Social Science Notes and Class 8 SST Part 2 Chapter 1 World Geography Some Glimpses Notes for effective learning.

Class 8 World Geography Some Glimpses Notes

World Geography Some Glimpses Notes Class 8

→ Bay: A broad inlet of the sea where the land curves inward, smaller than a gulf.

→ Canal: A human-made waterway connecting two water bodies.

→ Carbon Sink: A natural environment that absorbs and stores more carbon dioxide from the atmosphere than it releases.

→ Cartographer: A person who makes or draws maps.

→ Challenger Deep: The deepest point of the Mariana Trench.

→ Conservation Hotspot: An area with rich biodiversity where special efforts are made to protect plants and animals from threats.

→ Coral Bleaching: The process where corals turn white and die due to changes in water chemistry or temperature, often caused by human actions.

→ Coral Reef: A ridge in the ocean formed by corals that supports a rich variety of marine life.

→ Desert: A large, dry area of land receiving less than 25 cm of precipitation annually.

→ Distortion: The unavoidable misrepresentation of size, shape, or distance that occurs when flattening the Earth’s surface onto a map.

→ Fast Fashion: The quick production of low-cost clothes based on the latest trends, often made in countries with inexpensive labour. These clothes are usually thrown away soon as new fashion styles become popular.

→ Gulf Stream: A powerful, warm ocean current that flows from the Equator through the Atlantic towards Western Europe.

→ Gulf: A large inlet of the sea that cuts deeply into the surrounding land.

→ Map Projection: The process of representing the Earth’s surface on a flat map.

→ Mariana Trench: The deepest ocean trench in the world, located in the western Pacific ocean.

→ Mercator Projection: A map that preserves direction and shape but greatly exaggerates the size of landmasses near the poles.

→ Oasis: A fertile spot in a desert where water is found, typically supporting vegetation and human life.

→ Oblate Spheroid: The Earth’s shape; a sphere that bulges at the equator and is slightly flattened at the poles.

→ Ocean Current: A continuous, directed movement of seawater through the ocean.

→ Ocean Trench: A deep, V-shaped depression on the ocean floor, often formed by tectonic activity.

→ Permafrost: Soil that remains frozen for two or more years; it traps greenhouse gases like methane.

→ Plankton: Microscopic organisms that drift in water and form the base of the ocean food chain.

→ Plateau: A large, high area of relatively flat land that rises sharply above the surrounding area.

→ Rainforest: A dense forest that receives heavy rainfall and supports a great variety of plants and animals.

→ Robinson Projection: A compromise map projection that balances distortion of size and shape to give a more “realistic” view of the Earth.

→ Salt Flat: A large, flat area covered with a layer of salt, formed after water evaporates.

→ Savannah: A tropical grassland ecosystem characterised by wide-open spaces, scattered trees, and seasonal rainfall.

→ Sea: A large body of saltwater that is partially enclosed by land and connected to an ocean.

→ Steppe: A vast, treeless grassland found in temperate regions, with hot summers, cold winters, and moderate seasonal rainfall. It also acts as a natural carbon sink, absorbing and storing carbon from the atmosphere.

→ Strait: A narrow passage of water connecting two larger bodies of water, such as two seas.

→ Swamp: A wet area of land where water covers the ground for most of the year.

→ Tectonic: Related to the internal forces and movements of the Earth’s crust that create mountains and plateaus.

→ Third Pole: A term for the Tibetan Plateau because it contains the largest freshwater reserves outside the North and South Poles.

→ Tundra: A treeless, cold plain where the subsoil is permanently frozen.

→ Water Tower: A mountain region that stores freshwater in the form of glaciers and snow, feeding rivers below.

Introduction

• Rabindranath Tagore, observed that although modern advancements have brought the world geographically closer, they have also made it harder for people to form meaningful human connections.
• The Earth is described as the “blue planet”, not just because of its appearance from space but also because it is seen as a living entity and a nurturing mother, referred to as BhudcvT or Vasudha in various cultural traditions.
• Human life is deeply interconnected with physical geography, meaning that natural features directly affect human existence. For example, the Southern Indian Ocean plays a major role in influencing the monsoon system in the Gangetic Plains, showing how distant geographical features can impact local climates.
• The text sets the stage for a global exploration of Earth’s landscapes, including:
  • Towering mountains
  • Harsh deserts
  • Vast oceans
• It also highlights the importance of physical maps, which help us understand the “language” of the Earth’s surface and navigate its diverse features effectively.

The Complexity of Mapping the Earth

• Representing the Earth on a flat map is difficult because the planet is not perfectly spherical but an oblate spheroid, meaning it is slightly flattened at the poles and bulging at the equator.
• A curved surface cannot be flattened without distortion, similar to trying to spread an orange peel flat without tearing or stretching it, which makes map-making a complex task.
• To address this challenge, cartographers use different types of map projections, but each projection involves some compromise in accuracy.
• Different map projection preserve different features— some represent the shapes of countries more accurately, while others represent their sizes more accurately.
• Examples of projections include:
  • Mercator Projection: Useful for navigation because it preserves direction and shape but it greatly exaggerates the size of landmasses near the poles.
  • Robinson Projection: Designed to provide a visually balanced representation of the Earth, maintaining a compromise between size and shape.
• Since no single flat map can accurately represent all aspects of the Earth, it is important to:
  • Use multiple projections for comparison to understand the world.
  • Professionals use maps with latitude and longitude coordinates for precise locations.

The Blue of The Blue Planet, The Oceans

• The Earth is called the “blue planet” because approximately 71% of its surface is covered by oceans, making water the dominant feature of our planet.
• Oceans contain about 97% of Earth’s total water, most of which is saltwater.
• These vast water bodies are extremely important because they:
  • Support a wide variety of life forms, ranging from microscopic plankton to massive blue whales.
  • Act as a global climate regulators by absorbing and slowly releasing heat.
  • Add moisture to the air, helping to form clouds and rainfall.

The underwater world is as diverse as the land, with features such as:

• Mountains
• Valleys
• Plains

→ The Oceans

There are five oceans:

• Pacific Ocean – Largest and deepest ocean; home to whales and tuna.
• Atlantic Ocean- Second largest, busiest waterway for trade and transport, and an important fishing ground.
• Indian Ocean – Third largest, warm waters, rich biodiversity, historic international trade route.
• Southern Ocean – Fourth largest, encircles Antarctica; home to penguins and seals.
• Arctic Ocean – Smallest, shallowest, covered with sea ice; home to polar bears and walruses.

→ Ocean Currents

• Ocean currents function like large rivers flowing within the oceans, constantly moving water across different parts of the globe.
• They play a significant role in regulating regional climates and influencing weather patterns.
• Types of ocean currents:
  • Warm currents → Carry warm water from the equator towards the poles.
  • Cold currents → Carry cold water from the poles towards the equator.

Example:

• This warm current flows from the equator through the Atlantic Ocean towards Western Europe.
• Because of it, countries such as the United Kingdom experience a milder climate compared to other regions at similar latitudes.

→ Ocean Trenches

• Ocean trenches are very deep, V-shaped depressions on the ocean floor.
• The most famous example is the Mariana Trench.
• Its deepest point, Challenger Deep, extends more than 11,000 metres below sea level.
• The Mariana Trench is more than 2,000 metres deeper than the height of Mount Everest.
• These regions have extremely harsh conditions, including:
  • Complete darkness
  • Near-freezing temperatures
  • Immense water pressure
• Despite these conditions, scientists have discovered unique life forms in ocean trenches.
• As sunlight is absent, photosynthesis cannot take place. Instead, organisms use energy from chemicals in the ” water to produce food.

→ The Great Barrier Reef

• A reef is an elevated feature found close to or at the ocean’s surface, formed through natural processes or human activities.
• Natural reefs are either rocky structures or are formed by tiny sea animals called corals.
• Reefs are known as the “rainforests of the sea” because they support a great variety of marine life.
• They provide a habitat, food, and shelter for around one-quarter of all ocean species, including fish, crabs, turtles, and sponges.
• Major threats to reefs caused by human activities include:
  • Pollution
  • Overfishing
  • Climate change
• The Great Barrier Reef stretches for over 2,000 km along the northeastern coast of Australia and covers about 350,000 square kilometres.
• It is home to:
  • Hundreds of species of corals.
  • Thousands of species of fish and other sea animals.
• It is one of the largest and most significant natural ecosystems and is recognised as a UNESCO World Heritage Site.
• Conserving coral reefs is important to protect their rich biodiversity.
• These threats lead to coral bleaching, where corals lose their colour and die due to changes in ocean conditions, resulting in a loss of biodiversity.

→ Smaller Water Bodies and Waterways

• Apart from oceans, there are several smaller water bodies and waterways that are vital for trade, and transport.
• These include:
  • Seas → Large saltwater bodies connected to oceans (e.g., Arabian Sea).
  • Gulfs → Large inlets of the sea extending deep into the land (e.g., Persian Gulf).
  • Bays → Smaller, broad inlets of the sea (e.g., Bay of Bengal, the largest bay and has been important in trade).
  • Straits → Narrow natural passages connecting larger water bodies (e.g., Strait of Malacca).
  • Canals → Artificial waterways created by humans (e.g., Suez Canal).
  • Persian Gulf: An important trade route between India and Europe for thousands of years.
  • Bays: Provide safe locations for ports and dockyards by protecting them from strong ocean winds.
• The Suez Canal, opened in 1869, connects the Red Sea and Mediterranean Sea.
• The Suez Canal significantly created a waterway between the Indian Ocean and Europe, revolutionising global trade.

The Continents: Variety on Land

• The major landforms of the Earth include mountains, plateaus, plains, and deserts.
• Mountains are landforms that rise much higher than the surrounding area and have:
  • A broad base
  • Steep slopes
  • A narrow summit
• Plateaus are elevated landforms with a nearly flat surface and often have steep sides.
• Plains are broad, flat or gently rolling areas without large hills or deep valleys.
• Deserts are large, dry regions with very little rainfall and unique plants and animals.
  • Hot deserts – Sahara Desert (Africa), Thar Desert (Indian Subcontinent)
  • Cold deserts – Gobi Desert (Asia)
• A continent is a large, continuous landmass.
• There are seven continents: Asia, Africa, North America, South America, Antarctica, Europe and Australia.

Table: An Overview of the Seven Continents

Size (Largest to Smallest)	Continent	Population (approx.)	Area (million km2)	Key Fact
1st	Asia	4.8 billion	44.6	Largest and most populous continent; home to Mount Everest.
2nd	Africa	1.5 billion	30.3	Largest hot desert (Sahara) and longest river (Nile).
3rd	North America	610 million	24.7	Home to the Great Lakes and Rocky Mountains.
4th	South America	440 million	17.8	Home to the Amazon Rainforest and the Andes Mountains.
5th	Antarctica	No permanent population	14.0	Largest cold desert, coldest continent, and stores 70% of Earth’s freshwater.
6th	Europe	740 million	10.2	Second smallest continent with many countries.
7th	Australia	27 million	7.7	Smallest continent and only continent that is also a country.

→ Asia

Asia is the largest continent of the world. Some important land features of Asia are as follows:

Roof of the World —The Tibetan Plateau

• The Tibetan Plateau is the highest and largest plateau in the world.
• It is located north of the Himalayan Range.
• It was formed due to the collision of the Indo-Australian and Eurasian tectonic plates.
• It extends nearly 2,500 km east to west and about 1,000 km north to south.
• It has an average elevation of over 4,500 metres.
• It plays a major role in influencing the climate of Asia.
• It is the source of major rivers such as:
  • Indus
  • Brahmaputra
  • Yangtze
• Known as the “Third Pole”, because it contains the largest freshwater reserves outside the polar regions.
• Rising temperatures have increased snow-melt, causing existing lakes to grow larger and new lakes to form.

Gobi Desert in the ‘Land of the Eternal Blue Sky’:

• Deserts are dry regions that receive less than 25 cm of rainfall annually and cover about one-fifth of Earth’s land surface.
• Nearly one billion people live in desert regions according to National Geographic Society.
• The Gobi Desert is located in Mongolia with a part extending into northern China.
• Mongolia is known as the “Land of the Eternal Blue Sky” because it experiences about 8-9 months of sunny weather.
• Temperatures can drop to -30°C in winter, making it extremely harsh.
• The region has sparse vegetation.
• People often follow a nomadic lifestyle, moving with their herds to find pasture supported by underground water sources.

The Eurasian Steppes:

• The Eurasian Steppes are vast grasslands stretching over 8,000 km from west to east.
• It acts as a global carbon sink, absorbing carbon dioxide and helping reduce the greenhouse effect.
• It also serves as a resting ground for migratory birds, such as the Siberian crane.

The Urals:

• The Ural Mountains form a natural boundary between Europe and Asia.
• These mountains stretch for about 2,500 km, from the Arctic Ocean to Kazakhstan, and are rich in minerals such as:
  • Gold
  • Iron ore
  • Oil
  • Coal
  • Zinc
  • Natural gas
  • Platinum
  • Copper
• They form a natural boundary between Europe and Asia.
• The range is known for its rugged slopes, caves, valleys, and forests.
• They support diverse ecosystems including:
  • Deciduous forests
  • Coniferous Taiga forests
• These forests provide habitats for animals such as brown bears, wolves, lynx, elk, reindeer, and sable.
• The Urals have diverse landscapes, ranging from northern tundra and swamps to fertile southern farmlands, making them important for their rich biodiversity, scenic beauty, and economy.

Mountains (Water Towers):
Tectonic movements, volcanoes, and erosion create mountains. They influence the climate, act as water towers, | support biodiversity, and often form natural boundaries between countries.

→ Europe

• Europe is the second smallest continent of the Earth.
• It stretches from the Atlantic Ocean in the west to the Ural mountains in the east.

The European Plain:

• The European Plain is one of the largest flatlands in the world.
• It is characterised by low-lying land, gentle rolling hills, and broad river valleys.
• Its fertile soil, makes it one of the world’s most productive agricultural regions, where crops such as wheat, barley, rye and potatoes are widely grown.
• Its rivers have played an important role in trade and transport.
• The region is rich in resources such as coal, oil, natural gas.
• Its flat terrain and favourable climate have supported the growth of major cities such as Paris, Amsterdam, Moscow, Berlin, and Warsaw.
• The European Plain has witnessed many major battles and remains important for Europe’s agriculture and transport.
• The Alps are a crescent-shaped mountain range in south-central Europe.
• They form a natural barrier and are famous for their beautiful landscapes, skiing, hiking, and the peak of Mont Blanc.
• The Alps are home to diverse forests, alpine flowers, and wildlife such as brown bears, wolves, and golden eagles.
• The Alps provide water to major rivers such as the Rhine and the Danube, supplying drinking water, irrigation, and hydroelectric power.
• The region is also rich in minerals, forests, and fertile land.

→ Africa

• Africa is the second largest continent of the world.
• Africa has a variety of landforms, including deserts, grasslands, and rivers.
• The Sahara Desert is the largest hot desert in the world, with temperatures ranging from 30°C to 46°C, less than 25 cm of rainfall and very little vegetation.
• The Sahara has long been home to nomadic tribes who rear sheep, goats and camels and depend on trade for their livelihood.
• Ancient trade routes across the Sahara carried gold, salt and ideas to the Mediterranean world.
• The African Savannah is a tropical grassland rich in wildlife like lions and elephants, but it is threatened by human activities like, farming, deforestation and climate change.
• The Nile River, at 6,500 km, is the longest river in the world.
• It supported ancient Egyptian civilisation and remains a vital lifeline for irrigation, transport, drinking water, fishing and hydroelectric power.

→ South America

• The Andes Mountains are the largest mountain range in South America.
• The Andes include Mount Aconcagua, the highest peak in the Western Hemisphere, and Bolivia’s Uyuni Salt Flats, the world’s largest salt flat.
• The Andes supply water to the Amazon River, the largest river in the world by volume.
• The mountains support a rich variety of wildlife, with many species found only in this region.
• Only about one-fourth of the original flora and fauna remains, making the Andes an important conservation hotspot.
• The region is also rich in minerals such as silver, zinc, copper and lithium.
• The Atacama Desert in Chile is one of the driest places on Earth, stretching about 1,000 km.
• Temperatures in the Atacama Desert range from about 40°C during the day to 5°C at night.

The Amazon River and Rainforest:

• The Amazon River begins in the Andes Mountains of Peru and flows eastwards into the Atlantic Ocean, making it the longest river in South America.
• Its basin and tributaries nourish and support the Amazon Rainforest.
• Nearly 400 indigenous communities live in the rainforest and help conserve it.
• Deforestation and climate change threaten the Amazon Rainforest.
• Winds carry phosphorus-rich dust from the Sahara Desert to the Amazon, supplying essential nutrients to rainforest plants.

The Atacama Desert:

• The Atacama Desert is known for its clear night skies, making it one of the best places for stargazing.
• Its rocky, Mars-like landscape is used by NASA to test rovers.
• The desert has also become a major dumping ground for discarded clothes due to the growth of fast fashion.
• The United Nations (UN) has described this as an environmental and social emergency.

→ North America

North America is the third largest continent of the world.

The Colorado Plateau:

• The Colorado Plateau is a highland region in the southwest United States, famous for the Grand Canyon.
• It was formed by tectonic uplift and millions of years of erosion, creating striking red rock formations and deep canyons.
• The region is rich in natural resources such as coal, oil, natural gas, uranium, and copper.
• Its unique landscapes and geology make it an important tourist destination.
• The Rocky Mountains extend about 4,800 km and are rich in minerals like, gold, silver and copper.
• Mining, hydropower, tourism, and agriculture contribute to the region’s economy.
• The Rockies were once home to large Native American communities, many of whom now live on reservations.
• The Appalachian Mountains are among the oldest mountain ranges in the world.
• They have supported indigenous communities and are important for coal, timber, tourism, natural gas and renewable energy.
• The Great Lakes are a chain of five freshwater lakes, important for shipping, drinking water, commerce and wildlife but face environmental challenges.

National Park:

• Yellowstone National Park is a well-known example of ecosystem restoration.
• Excessive grazing by elk had disturbed the natural balance of the ecosystem.
• Wolves were reintroduced in 1995 to control the elk population.
• This allowed vegetation to recover and helped restore ecological balance.

→ The Australian Continent

• Australia is the smallest continent on the Earth.
• A large part of Australia is arid and known as the Great Australian Desert. It includes areas such as the Great Victoria Desert.
• It supports unique wildlife, including:
  • Wallabies
  • Dingoes
  • Feral camels
• It is also home to rare animals such as the sandhill dunnart, marsupial mole and mallee fowl, many of which are struggling to survive.
• The indigenous Spinifex people have lived here for over 25,000 years.
• The desert region attracts tourist for its unique geography, wildlife and the preserved culture of the Spinifex.

→ Antarctica

• Deserts are not always hot; some are cold as well.
• Antarctica is the largest and coldest desert on Earth, covering over 14 million square kilometres, more than four times the size of India.
• It is even colder than the Arctic, the Earth’s other polar desert.