o level geography notes Archives - Page 2 of 7 - Free ZIMSEC & Cambridge Revision Notes

Humidity

By garikaib|2025-02-12T09:08:25+02:00February 12th, 2025|O Level Geography, Weather and Climate|

Wet and dry bulb thermometer. Image by TradeIndia ZIMSEC O Level Geography Notes: Humidity

-a quantity representing the amount of water vapor in the atmosphere.

It is measured using a hydrometer.
The wet and dry bulb thermometer is also known as a psychrometer.
Weather satellites can […]

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Plate tectonics

By garikaib|2025-02-12T09:14:08+02:00February 12th, 2025|Landform Studies, Notes, O Level Geography, Ordinary Level Notes|

Major Plates of the world. Image by Learner.org ZIMSEC O Level Geography Notes: Plate Tectonics

The lithosphere (that is the earth’s crust and the rigid part of the mantle) is divided into seven large and several smaller plates.
A plate is a rock that is found […]

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Limestone pavements

By garikaib|2025-02-12T09:24:56+02:00February 12th, 2025|Landform Studies, Notes, O Level Geography, Ordinary Level Notes|

Clints and grikes. Image credit nen.gov.uk. ZIMSEC O Level Geography Notes: Limestone pavements

Limestone pavements are flat areas of exposed limestone rocks.
They are part of the dissolved bedding plate which may have been exposed because the surface soil may have been removed by glacial activity […]

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River processes: Basic Concepts

By garikaib|2025-02-12T09:13:58+02:00February 12th, 2025|Notes, O Level Geography, Ordinary Level Notes, River Processes|

A turbulent river. Image credit jokeroo.com ZIMSEC O Level Geography Notes: River processes:Basic Concepts.

Rivers are perhaps the most important denudation agent.
They carve channels, form valleys,transport and deposit regolith over great distances and other material to form other types of landforms.

Terms used in describing a […]

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Pressure

By garikaib|2025-02-12T09:09:34+02:00February 12th, 2025|O Level Geography, Weather and Climate|

An aneroid barometer. Image imgkid. ZIMSEC O Level Geography Notes: Pressure.

-is the pressure exerted by the weight of air in the atmosphere of Earth. It is measured in millibars. It is measured using an instrument known as a barometer. There are two different types of […]

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Convergence and collision zones/plates

By garikaib|2025-02-12T09:16:29+02:00February 12th, 2025|Landform Studies, Notes, O Level Geography, Ordinary Level Notes|

Convergence zone. Image by Coft.edu ZIMSEC O Level Geography Notes: Plate tectonics: Convergence Zone.

Convergence zone

Are also know as destructive plates (zones) or the zone of subduction.
This is when two plates move towards each other as shown on the diagram above.
An Ocean crust moves towards a […]

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People and Weathering

By garikaib|2025-02-12T09:27:03+02:00February 12th, 2025|Landform Studies, Notes, O Level Geography, Ordinary Level Notes|

Air pollution results in increased incidences of acid rain. Image credit airbetter.org ZIMSEC O Level Geography Notes: People and weathering

How humans influence weather?

Human activities such as industrialisation and driving of cars produce emissions such as sulphur dioxide,nitric oxide […]

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River transportation processes

By garikaib|2025-02-12T09:20:18+02:00February 12th, 2025|Notes, O Level Geography, Ordinary Level Notes, River Processes|

River transportation processes. Image credit BBC. ZIMSEC O Level Geography Notes: River Transportation Processes.

Any energy left after a river has overcome friction is used to transport sediment.
This energy varies directly with a river’s discharge, velocity and turbulence
That is if they increase the amount of […]

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Clouds

By garikaib|2025-02-12T09:11:51+02:00February 12th, 2025|O Level Geography, Weather and Climate|

Clouds. Image by ThirdScribe. ZIMSEC O Level Geography Notes: Clouds

Refers to the fraction of the sky obscured by clouds when observed from a particular location. Okta is the usual unit of measurement of the cloud cover. Sky conditions are estimated in terms of how many eighths of the […]

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Divergence/Constructive zone/plates

By garikaib|2025-02-12T09:18:09+02:00February 12th, 2025|Landform Studies, Notes, O Level Geography, Ordinary Level Notes|

Divergent plates. Image by Cornel. ZIMSEC O Level Geography Notes: Plate Tectonics: Convergence Plates

In a divergence zone plates move away from one another thus the name “divergence.”
Magma up-wells from the mantle to fill the gap left by the diverging plates.
The magma provides new material to form […]

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February 2025