The earth crust consists of rocks. A rock is any mineral material of the earth. It may be a combination of different mineral element such as silica which contains silicon and oxygen. All the rocks differ from one another in texture, structure, colour, permeability, mode of occurrence and degree of resistance to denudation. Types…
The internal structure of the earth is made up of three concentric layers which are (a) The crust (Lithosphere) (b) The mantle (Mesosphere) (c) The core (Barysphere) The Crust This is subdivided into upper and lower crust. The upper crust consists of granite rocks and forms the continent. The main minerals here are silica…
The structure of the earth is grouped into two zones: The outer structure and the internal structure. THE OUTER STRUCTURE OF THE EARTH The outer structure of the earth is made up of four zones or layers: Lithosphere Hydrosphere Atmosphere Biosphere Lithosphere: This is the solid portion of the earth. It is the outermost zone…
Calculation of distance using lines of latitude Procedures: locate the two places involved find the latitude difference between the two places Note: North-North= subtract North-South= add South-North= add Equator-North= add or subtract Equator-South= add or subtract multiply the latitude difference by 111km 1°=111km( 1° of latitude is approx. 111km on land) Example 1…
MEANING OF LATITUDE Latitude is an angular distance of a point on earth’s surface measured in degrees from the centre of the earth. Latitude is parallel to the equator .Equator divides the earth into two equal halves known as Northern & southern hemisphere. Lines of latitude are sometimes called parallel of latitude. IMPORTANT LINES…
The shape of the earth The earth has a spherical shape. Its shape can also be described as GEOID. Though we walk on “flat” surface, it is almost like a sphere and it is slightly flattened at the two poles. There are many facts to prove that the earth is spherical. Size of the Earth…
Solar system is the description of the position of the earth and other planets in relation to the sun. The solar system comprises of the sun and the nine planets. All the planets revolve round the sun in “elliptical orbits”. The Universe The universe is made up of many heavenly bodies, group of stars…
INTRODUCTION TO GEOGRAPHY: MEANING, SCOPE AND VALUE MEANING OF GEOGRAPHY The word Geography is derived from the Greek word ‘Geo’ meaning the earth, and ‘graph’ which means description. Geography can therefore be defined as the description of the earth. However, Geography does not only describe the surface of the earth and its features. It also…
GREEK SYSTEM OF CLASSIFICATION OF CLIMATE This is one of the earliest climatic classification which was made by the Greeks. The basis for the Greek classification is temperature. This system of classification divides the world into three climatic zones. These zones are: Torrid zone: This zone is found within the tropics. It is very hot…
Climate is the average weather condition of the atmosphere over a long period of time usually about 30-35years. FACTORS THAT CAN AFFECT OR DETEMINE CLIMATE Latitude 6. Cloud cover Altitude 7. Vegetation Distance from the sea 8. Planetary wind Ocean currents Elements of climate Temperature Rainfall Wind Relative humidity Pressure Cloud cover Sunshine…
The action of wave as an important agent of erosion, transportation and deposition of material is confined to the coast of seas and oceans. The rate of marine erosion depends on the nature of the rocks, the amount of rock exposed to the sea, the effects of tides and currents and human interference in coast…
The action of glacier is an important agent of erosion, transportation and deposition in temperate regions or mountainous regions. TERMS ASSOCIATED WITH GLACIER Ice: This is solid form of water which results from freezing when the temperature is below 00 Snow: This refers to frozen water vapour that falls in form of crystals from…
ACTION OF WIND IN THE DESERT The action of wind is dominant in desert and other semi arid regions of the world. Deserts are places with little or no vegetation. Deserts which are associated with aridity (dryness) are caused by low rainfall, high temperature, cold currents and high evaporation rate. Examples of Deserts are: (i) …
ACTION OF RUNNING WATER (RIVER) Running water is one of the most important agents of denudation. Rivers are involved in erosion transportation and deposition of materials. TERMS ASSOCIATED WITH RIVERS (1) Source of a river: The source a river refers to where a river starts or begins, usually around highlands. (2) Course of a river:…
Trade is the buying and selling of goods and services between one region and another, within the same country or between one country and another. The former is known as internal trade while the latter is called international trade. Types of Trade International Trade This trade is divided into two groups. They are: Import…
International Economic Co-operation of West African state (ECOWAS) The economic community of West African states (ECOWAS) is a sub-regional organization formed by West African countries mainly to promote co-operation and development in all economic fields and to contribute to the progress and development of the African continent. ORIGIN OF ECOWAS The treaty…
Climate Change Meaning and Nature of Climate Change Climatic change refers to large scale alteration in the normal cycle of weather over pronounced time or duration. This change or alteration is expressed in the irregularities (anomalies) of the cycle or regimes of major elements such as rainfall, solar radiation, temperature, pressure patterns and all-other elements…
Mass movement can be defined as the movement of weathered materials (regolith) on slope under the force of gravity. It can also be referred to as the movement of rock materials from one place to another under influence of gravity. FACTORS THAT AFFECT MASS MOVEMENT These are factors that affect mass movement Gradient…
Weathering is the disintegration and decay of rocks which is caused by forces of weather such as frost, rain and temperature changes. It can also be defined as the process by which rocks are broken down into smaller fragments by weather forces/atmospheric forces. It is a process of rocks breaking and decaying which are caused…
Denudation is the process of lowering or sculpturing the earth surface by the activities of certain agents called denudation. The word denude is an original Greek word for reduction, that is, lowering or cutting. Therefore, denudation process are processes that contribute to lowering or reshaping the earth. Types of Denudational Processes Denudation involves four…