ICSE Class 9 Geography Syllabus

Approximately what percentage of the Earth's surface is covered by water, and what fraction of that is fresh water?

About 71% of the Earth's surface is water; only about 2.5–3% of all water is fresh water, and most of that is locked in glaciers and ice caps.

Name the four major oceans of the world in order of size.

Pacific Ocean (largest), Atlantic Ocean, Indian Ocean, and Arctic Ocean (smallest). (The Southern/Antarctic Ocean is now also recognised.)

What are ocean currents and how are warm and cold currents different?

Ocean currents are large-scale movements of seawater in fixed directions. Warm currents flow from the equator toward the poles; cold currents flow from the poles toward the equator.

What are tides and what causes them?

Tides are the periodic rise and fall of sea level, caused mainly by the gravitational pull of the Moon (and Sun) on the ocean waters.

Differentiate between spring tides and neap tides.

Spring tides are the highest tides, occurring at full and new moon when Sun, Moon and Earth are aligned. Neap tides are the lowest tides, occurring at first and third quarter when Sun and Moon are at right angles to Earth.

What is salinity of ocean water and what is its average value?

Salinity is the amount of dissolved salt in seawater, measured in parts per thousand (‰). The average ocean salinity is about 35‰ (35 grams of salt per kilogram of water).

Name the layers of the atmosphere in order from the Earth's surface upward.

Troposphere, Stratosphere, Mesosphere, Thermosphere (Ionosphere), and Exosphere.

In which atmospheric layer does weather occur, and why?

Weather occurs in the troposphere because it contains almost all the water vapour, dust and clouds, and is where temperature decreases with height.

What is the importance of the ozone layer and in which atmospheric layer is it found?

The ozone layer, located in the stratosphere, absorbs the Sun's harmful ultraviolet (UV) radiation, protecting life on Earth.

List the major gases of the atmosphere and their approximate percentages.

Nitrogen ~78%, Oxygen ~21%, Argon ~0.93%, Carbon dioxide ~0.03–0.04%, plus traces of other gases and variable water vapour.

Define weather and climate and state the key difference.

Weather is the day-to-day, short-term state of the atmosphere at a place. Climate is the average weather of a place over a long period (about 30 years). The difference is the time scale.

What is atmospheric pressure and how does it change with altitude?

Atmospheric pressure is the weight of the air column pressing on a unit area of the Earth's surface. It decreases as altitude increases because air gets thinner.

What is humidity, and what is relative humidity?

Humidity is the amount of water vapour in the air. Relative humidity is the ratio (in %) of the actual water vapour present to the maximum the air can hold at that temperature.

Name the three main types of rainfall.

Convectional rainfall, Orographic (relief) rainfall, and Cyclonic (frontal) rainfall.

How is orographic (relief) rainfall formed?

Moist air is forced to rise over a mountain barrier; it cools, condenses and falls as rain on the windward side, leaving a dry 'rain shadow' on the leeward side.

What is the biosphere?

The biosphere is the narrow zone of the Earth where land, water and air interact and where all living organisms (plants, animals, microbes) exist.

What is an ecosystem?

An ecosystem is a community of living organisms interacting with one another and with their non-living physical environment as a single functional unit.

Differentiate between biotic and abiotic components of an ecosystem.

Biotic components are the living parts — plants, animals and microorganisms. Abiotic components are the non-living parts — air, water, soil, sunlight and temperature.

In an ecosystem, what are producers, consumers and decomposers?

Producers (green plants) make their own food by photosynthesis; consumers (animals) eat other organisms; decomposers (bacteria, fungi) break down dead matter and recycle nutrients.

What is a food chain?

A food chain is the sequence of organisms through which energy and nutrients flow as one organism is eaten by another, e.g., grass → grasshopper → frog → snake → hawk.

What is biodiversity and why is it important?

Biodiversity is the variety of all living organisms — plants, animals and microbes — in a region. It maintains ecological balance, provides resources, and keeps ecosystems stable and resilient.

What are the primary, secondary and tertiary sectors of economic activity?

Primary: extracting natural resources (farming, fishing, mining). Secondary: manufacturing/processing raw materials into goods. Tertiary: providing services (transport, trade, banking, education).

Differentiate between subsistence and commercial farming.

Subsistence farming produces food mainly for the farmer's own family with little surplus. Commercial farming produces crops/livestock on a large scale for sale in the market for profit.

What is the difference between renewable and non-renewable resources? Give one example of each.

Renewable resources can be replenished naturally within a short time (e.g., solar energy, water, forests). Non-renewable resources are finite and cannot be replaced quickly (e.g., coal, petroleum, natural gas).

Distinguish between an earthquake's focus and its epicentre.

The focus (hypocentre) is the point inside the Earth where an earthquake originates. The epicentre is the point on the Earth's surface directly above the focus, where shaking is felt most strongly.

What instrument measures earthquakes, and on what scale is their magnitude measured?

Earthquakes are recorded by a seismograph; their magnitude is measured on the Richter scale (intensity is measured on the Mercalli scale).

What is a tsunami and what usually causes it?

A tsunami is a series of very large, fast ocean waves usually caused by a submarine (undersea) earthquake, volcanic eruption or landslide displacing huge volumes of water.

Differentiate between a cyclone and a flood as natural disasters.

A cyclone is a violent storm with a low-pressure centre and strong rotating winds and heavy rain. A flood is the overflow of water submerging normally dry land, often caused by heavy rain, river overflow, or cyclones.

What are the four main types of pollution?

Air pollution, Water pollution, Soil (land) pollution, and Noise pollution.

Name two major causes of air pollution and one of its harmful effects.

Causes: burning of fossil fuels (vehicles, factories) and industrial smoke/emissions. Harmful effect: respiratory diseases, acid rain, and global warming.

What is the greenhouse effect and which gas is most responsible for it?

The greenhouse effect is the trapping of the Sun's heat by certain gases in the atmosphere, warming the Earth. Carbon dioxide (CO₂) is the main greenhouse gas; methane and CFCs also contribute.