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🌍 2018 NECO GCE ➖ Geography 🌍
🔥 Theory 🔥
Characteristics of Igneous Rocks:
(i) They are crystalline in structure i.e. they contain crystals.
(ii) They do not occur in layers i.e. they are non-stratified rocks.
(iii) They do not contain fossils.
(iv) They are usually hard and impervious.
Mode of Formation of Igneous Rocks:
They are formed by the cooling and solidification of molten rocks called magma, ejected from beneath the earth’s crust. The magma which results from high temperature and pressure beneath the earth, forces itself towards the earth’s surface through cracks. As the magma moves towards the surface, it comes in contact with lower temperature, hence it cools and solidifies to form igneous rocks.
Uses of Rocks to Man:
(i) They are used as sources of fuel for domestic and industrial uses.
(ii) Some beautiful rocks such as marble can be polished as ornaments for decorating floors, walls of buildings, etc.
(iii) Soils are formed from disintegration of rocks.
(iv) They are sources if metals which are derived from mines e.g. gold, silver, copper, etc.
Two Types of Plains:
(i) Structural Plains: These are relatively undisturbed horizontal surfaces of the earth, formed by bedded sedimentary rocks. Examples include the Russian platform and the Great Plains of the USA.
(ii) Erosional Plains: These plains are formed by the agents of denudations such as rivers, wind, rain, glacier and ocean waves which wear out irregular rock surfaces and smoothen then into plains know as erosion plains.
Differences Between Weather and Climate
(i) Weather is the condition of the atmosphere in a specific place at a given point in time; these atmospheric conditions may take place day by day, minute by minute or seasonally.
(ii) Weather may involve just one condition of the atmosphere
(iii) Weather occurs in a place within a short period
(iv) Weather is what you get on a daily basis
(v) Weather changes within a short time
(vi) The scientific study of waether is called meteorology and a meteorologist studies weather
(i) Climate is the average weather conditions over a place and it mostly take place after 30 years of time
(ii) Climate includes all the conditions of the atmosphere such as temperature, precipitation, wind, humidity, cloud and pressure
(iii) Climate takes place over long period of time
(iv) Climate is what you expect over a long time
(v) The overall changes and variations of a climate are very stable and may take decades or centuries to ocxur
(vi) The scientific study of climate is called climatology and a climatologist studies climate
Factors That Affect Weather and Climate:
Pick Any Four (4)
(i) Latitude and Altitude
Latitude, or how far one is from the equator, greatly affects the climate and weather of an area. If you live close to the equator, the climate will be warmer, while moving north or south from the equator brings a cooler climate. Altitude, or how high one is above sea level, has a similar effect–the higher the elevation, the colder the climate.
(ii) Proximity to the Ocean
Land and water retain different amounts of heat. Land heats more quickly than water, but water holds heat longer. Proximity to water moderates the climate, while inland climates are harsher. Those living near the water will experience breezy, moist weather, when the warm air from the land meets the cooler air from the water and and rises, making for a windy climate with precipitation. The further inland one goes, the drier the climate in most regions.
Mountain areas are generally colder than surrounding land due to higher altitudes.
Mountainous regions block the flow of air masses, which rise to pass over the higher terrain. The rising air is cooled, which causes condensation of water vapor, and precipitation. This being the case, one side of a mountain, the windward side, will often have more precipitation and vegetation; the leeward side is often drier.
Just as climate determines the types of vegetation in a given region, to a certain extent vegetation can contribute to a region’s weather. Hot and wet climates in the tropics, for instance, develop rainforests; the more trees and plants there are, the more water vapor in the atmosphere and the moister and cooler the area. Along the same line, dry climates will often enable the growth of grasslands or savannas with little water vapor to contribute to the atmosphere, maintaining drier weather patterns.
(v) Earth’s Tilt
Since Earth’s axis is tilted at 23.5 degrees, we have seasons. One hemisphere leans toward the sun half the year while the other leans away, and then the situation reverses. Though the climates of the Earth’s regions (tropical, temperate, or polar) remain the same no matter the season, the weather is affected.
(i) Tropical: Around the Equator we have tropical climates which are hot and humid, this is where you’ll find the world’s rainforests.
(ii) Arid: Then there are arid or dry climates – like you’d find in deserts.
(iii) Mediterranean: With hot dry summers, and cooler wetter winters.
(iv) Temperate: Temperate climates. That’s what we have in the UK, where summers are mild and winters aren’t too cold.
(v) Continental: In areas that are a very long way from the sea, the climate is continental with long, cold winters and short, hot summers.
(vi) Polar: There’s polar climates which experience long periods of extreme cold.
Environmental resources are useful things (both living and non-living) occurring naturally within a particular geographical location which are benefit to man, animals and plants.
(ii) Barks of trees.
(i) Poor technological know-how, such as storage.
(ii) Inadequate capital i.e. high cost of harnessing it.
(iii) Unreliability e.g. periods when the sun is not overhead.
(i) The increase in ultra-violet rays increases the amount of solar radiation on the earth’s surface.
(ii) Excessive ultra-violet rays leads to increase in skin cancer in man.
(iii) Possible increase in precipitation.