December 3, 2022

Average weather conditions of a given place over a long period of time usually 30-35 years. Factors Influencing Climate Latitude It influences temperature whereby low latitudes have high temperature and high latitudes have low temperature due to the angle at which the sun rays strike the earth and the distance travelled by the suns rays. It also influences rainfall whereby places in the equator receive rainfall in two seasons when the sun is overhead there while northern and southern tropical areas receive rainfall when the position of the sun is overhead in those areas. Inter-Tropical Convergence Zone It’s a low pressure belt around equator where trade winds converge. It influences rainfall in the following ways: Places further from equator experience one rainy season when the sun is overhead and a long dry season when the sun is in the S. hemisphere. Regions near equator have 2 seasons of heavy rainfall because they experience passage of ITCZ twice. Altitude It influences temperature whereby at low altitude temperature is high while at high altitude its lower due to the thickness of atmosphere determining the number of particles to store heat and distance from space where terrestrial radiation is lost. It also influences rainfall whereby mountains on the path of rain winds receive Orographic rainfall and the windward slopes receive heavier rainfall than leeward slopes. Distance from the Sea It influences temperature whereby places in temperate regions near the sea experience low temperature during summer onshore winds blowing over cold ocean water and taking the cooling influence on adjacent land because the water is heated at a slower rate than land. Places near the sea also experience higher temperatures during the winter or cool season due to sea breezes carrying warmer air to the land because water loses heat at a slower rate than land. Temperatures in the interior of continents tend to be high in summer and very low in winter due to lack of marine influence. It also influences rainfall whereby coastal regions receive a lot of rain when the winds are onshore and the continental interiors receive less rain mainly in summer because onshore winds will have dropped most of moisture along the way. Ocean Currents It influences temperature whereby coasts which are washed by warm ocean currents are warmer while those washed by cold ocean currents are cooler due to the onshore winds being either warmed or cooled and then taking the warmth or coolness to the land. It influences rainfall whereby coasts washed by warm ocean currents experience heavy rainfall when moist onshore winds are warmed by the current and made to hold on to moisture which they release on reaching the land. The coasts washed by cold ocean currents on the other hand experience low rainfall as a result of moist winds being cooled and moisture in them condensed resulting in rain falling over the ocean thereby bringing little or no rain to the coastal areas. This is the cause of western margin deserts e.g. Kalahari and Namib deserts. Aspect Direction of slope in relation to sunlight and the rain bearing winds. Its effect on temperature is more pronounced in the northern and southern hemisphere. In the N and S hemispheres the slopes facing sun are warmer while those facing away are cooler. The slopes in the direction of rain winds i.e. the windward slopes receive heavier relief rainfall than the leeward side. Winds and Air Masses Wind blowing from a warm region warms the region its passing over and if blowing from a cool region cools the region it’s passing over since wind is a medium of transfer of heat. Sea breezes take cooling influence on land during hot afternoons. Katabatic winds cause low night temperatures on valleys and foot of mountains. Fohn and Chinook which are descending dry winds take dryness to the leeward sides of Alps and Rockies. Winds influence rainfall in the following ways: Anabatic winds cause afternoon showers on mountainous regions. Moisture laden winds cause heavy rainfall. Persistent dry winds cause desert like conditions in the area they pass over e.g. Harmattan winds from Sahara which blow over W. Africa. Regions around large water bodies experience high rainfall because of the effect of land breezes. Configuration of Coastline Coastal regions across the path of moisture laden winds receive higher rainfall because winds deposit moisture on land e.g. Mombasa while those lying parallel to the path of those winds receive less rainfall because moisture is deposited on the sea e.g. Lamu. Forests Forested areas experience a micro climate whereby: Temperature is lower due to shades of trees reducing solar insolation reaching the ground. Rainfall is heavier due to high rate of evapotranspiration and friction between trees and rain bearing winds. Human Activities Man has caused deforestation in the process of creating room for settlement and agriculture which has caused drop in rainfall amounts leading to semi-arid conditions. Man has constructed dams across rivers and done afforestation which has caused semi-arid regions to become wetland. Gases especially co2 emitted from burning fossil fuels and chlorofluorocarbons layer cause global warming through the green house effect and destruction of ozone layer respectively. Modified Equatorial Climate Experienced along the coast and along the coast from Somali-Tanzanian border and L. Victoria basin regions around the lake. Along the Coast Characteristics High temperatures throughout the year mean annual about 27◦c. Small mean annual range of temperature about 4◦c. Hottest months are December and January. Experiences rainfall throughout the year/ no real dry season. Double maxima rainfall regime (2 rain seasons) in May and October. High humidity due to high temperature causing high rates of evaporation and nearness to the sea. Victoria Basin Characteristics Temperature is lower than the truly equatorial climate due to modifying influence of the lake (mean annual range between 22-26◦c). There are no real dry months. Heavy rainfall ranging from 1000-600mm. Double maxima rainfall regime. Receives convectional type of rainfall which falls mainly in the afternoons. High relative humidity due to high temperature and nearness

A photograph is an image of an object, person or scene recorded by a camera on a light sensitive film or paper. Types of Photographs  1. Ground Photographs -Taken from the ground. They are of 2 types: Ground Horizontals- taken with the camera at the same level as the object. They are of 2 types. Ground close ups/particular view photographs-taken from the ground with a camera focused on one particular object. Ground General View Photographs-taken from the ground with camera focused on general scenery. Ground Obliques-taken from the ground with a camera slanting/held at an angle. 2. Aerial Photographs Taken from the air e.g. from aircrafts, balloons or satellites. They are of 2 types: Aerial Obliques-taken from the air with camera tilted towards the ground. Vertical Aerial Photographs-taken from the air with the camera directly above the object or scenery. Uses of Photographs Used in learning geography because they bring unfamiliar features in the classroom enabling the students to understand them better. Photographs showing vegetation and human activities can be used to deduce the climate of an area. Aerial photographs show vital information on land use. Photographs showing land forming processes help us to understand those processes. Limitations in the Use of Photographs Coloured photographs are generally expensive to produce. Black and white photographs don’t show the real colours of objects or scenery e.g. it’s difficult to distinguish ripe coffee berries from green ones. Some aerial photographs have objects which are far away and hence unclear which may lead to the wrong interpretation. Vertical aerial photographs are difficult to interpret without special instruments like stereoscopes. Photographs are difficult to interpret if they are brulled because it’s difficult to distinguish objects which look similar e.g. wheat and barley. Interpretation of Photographs Means to explain the meaning of the objects or features on a photograph. It involves the following: Determining the Title Photographs show human activities, physical features, natural catastrophes etc e.g. nomadic pastoralism, drought, flooding, etc. when determining the title  examine the photograph carefully and apply the knowledge you have learnt in geography. Estimating Time In the tropics the shadows are short at noon and longest in the morning and afternoon. If the camera is facing south and the shadow is cast to the right it’s in the morning and if cast to the left it’s in the afternoon. Estimating Season Dry season Bright clear skies Dry vegetation harvesting Light clothes e.g. shirts and T-shirts since temperature is high (also an indication of high temperature. Rainy season Rain clouds Luxuriant vegetation Young crops Flowering plants Weeding Heavy clothing e.g. pullovers or jackets since temps are low (also an indication of cool season). Determining Compass Direction It it’s in the morning and the shadow of flag pole is cast to the left the photographer is facing north and if cast to the right he was facing south. It it’s in the morning and the shadow is facing towards you the photographer was facing east and it taken in the afternoon and the shadow is facing towards you the photographer was facing west. Interpretation of Physical Features on Photographs Relief Flat land Rice crop Irrigation Combine harvesters Swamps Meanders Oxbow lakes Inselbergs (isolated hills) Hilly/Mountainous landscape/Highland Area Steep slopes Terraced landscape Tea, wheat crops which grow at high altitude rapids Water falls Interlocking spurs Drainage Youthful Stage Rapids Waterfalls   Interlocking spurs Middle Stage meanders oxbow lakes Lower Stage deltas distributaries meanders and oxbow lakes flood plain Vegetation Natural Indigenous species Dense undergrowth Trees grow haphazardly Different species of trees Not of the same height Planted Exotic species In rows Little undergrowth Same species Same heights Tropical Rain Forests Trees Broad leaves Umbrella shaped Marshes swamps Savannah Grassland Grass and short trees (woodland). Desert Vegetation Thorny leaves Baobab and acacia Scrub-land covered with shrubs and underdeveloped trees (shrubs). Climate High Temperatures and low rainfall Sugar cane Grass Sisal Scrub and bush land vegetation Dense forests Light clothes Cool Temperature and High rainfall (Sufficient, Reliable and well distributed) Tea Coffee Wheat Dairy farming Soils Acidic and Volcanic Soils Coffee Tea Clay Soils Rice Black Cotton Soils Cotton Rice Loamy Soil Horticultural crops Human Activities and evidence Settlement Group of dwellings where people live. Rural Settlements Semi permanent houses Farming or fishing activity Uneven distribution of settlements Presence of villages Urban Settlements Permanent buildings Storied buildings Heavy traffic presence Regular street patterns Agriculture/Farming Subsistence Farming Temporary and permanent houses Small pieces of land Mixed cropping Simple implements Local and exotic breeds of livestock Crop farming Crops People preparing land or weeding or Harvesting Commercial Crop Farming cash crops machinery feeder routes processing factories Plantation Farming Single crop on extensive piece of land e.g. tea, coffee, etc. Many labourers Nucleated settlement within farms Livestock Rearing Nomadic Pastoralism Cattle grazing in a grassland or semi-arid region Daily Farming Zero grazing Cattle with big udders Ranching Paddocks Wind mills Mining Quarry Large open pits Large excavators Lorries carrying loads of rocks Industrial Manufacturing Buildings with large chimneys People engaged in a processing activity such as Jua kali artisans. Lumbering People cutting trees using power saws People loading timber into lorries Logs pilled near a saw mill Forests with stumps Logs floating on a river Transport Motor transport Vehicles on roads Railway Transport Railway line Trains Air Transport Flat tarmacked piece of land Aircraft Water Transport Boats Ships Ferries Communication Telephone lines Telephone booths Post office Satellite masts V and radio stations Sketching Diagrams from Photographs Draw a rectangle the same size as the photograph. Divide it into squares using faint lines. Subdivide the photograph into 9 sections. Insert the features in their exact positions using simple lines being guided by the squares. Label the important features e.g. vegetation, land use, prominent buildings, transport, and communication. Give the sketch a suitable title. Graphs 2 dimensional drawings which show relationships between 2 types of data representing two items also called variables. These are dependent variable which is affected by the other e.g. temperature (on y axis) and independent variable

Map – representation of the whole or part of the earth’s surface drawn to scale. Shows outline of objects on the ground Drawn as if the drawer was above the ground It shows details Most of the features are indicated by symbols. Picture: image of a real object. Gives details in their visible shapes and sizes Can be inform of free hand, drawing, painting or a photograph Not drawn to scale Plan: outline of something drawn to scale. Also drawn as if a person was directly above the ground It represents a very small place The scale is large to show details e.g. house plan Gives specific information Types of Maps Classified according to the purpose for which each map is drawn. Topographical Maps: This shows selected natural physical features on a small portion of a country. Atlas maps: this is a collection of maps in one volume. Sketch maps: maps which are roughly drawn. A good sketch map should have the following characteristics: neat and clear title frame key compass direction Uses of Maps Sketch maps are used to summarise information for easy reference. Used for locating other countries. Used for comparing sizes of countries. For locating climatic regions of different parts of the world. Give information on distribution of geographical phenomena e.g. vegetation on the earth’s surface. Help travellers to find their way. Used to calculate distance of a certain place. Used to locate physical features like landforms. Marginal Information Information contained in the area surrounding the map. Map name e.g. Yimbo. Sheet title e.g. East Africa 1:50000 (Kenya). grid system numbers latitudes and longitudes Compass direction with grid, true and magnetic north. scales key publisher and copyright Map identification Map series Sheet number or sheet index Map Scales A scale is a ratio of a distance on a map to a corresponding distance on the ground. Types of Scales Statement scale –expressed in words e.g. 1cm represents 1km, 1cm to 1km. Representative Fraction (RF)-expressed as a fraction or ratio e.g. 1/200,000 or 1:200,000. Linear scale-shown by a line which is subdivided into smaller units. Conversion of Scales Statement scale into RF 1cm rep 1km to RF Multiply the number of kilometres by 100,000 (1km=100,000cm) i.e. 1×100000=100,000. Statement scale is 1/100,000 or 1:100,000. 2cm rep 1km Divide both sides by two to get 1cm rep ½ kilometres. Multiply ½ by 100,000 to get 50,000. RF is 1/50,000 or 1:50,000. RF to Statement Scale Divide the denominator by 100,000. Write the scale in statement form. Linear Scale to Statement Scale Measure a unit distance off a linear scale e.g. The distance is 4-3=1km which is represented by 2cm. Use the methods in (1) and (2) above. Given that the ground distance is 200km while the distance on map is 20cm calculate the scale. Sizes of Scales Small scales- show a large area of land on a small size of paper. They show limited details e.g. 1:250,000, 1:500,000, 1:1,000,000. Medium scales- used to represent a relatively smaller area on a given size of paper e.g. 1:50,000, 1:100,000, 1:125,000. Large scales-used to represent a small area of land on a given piece of paper. They show a lot of details e.g. 1:2,500, 1:10,000, 1:25000 Arranging Scales in Order Ascending Order-smallest to largest Descending Order-largest to smallest (1)1/500,000 (3)1:25,000 (4)1/10,000 (2)1cm rep 500m Uses of Scales Estimating distances on maps Measuring distances accurately-use dividers and ruler, piece of string or thread for curved distances or straight edge of paper. E.g. calculate actual distance of a line 8.5cm long on a map using the following scales. 2cm rep 1km 1:100,000 Calculation of areas-no. of full grid squares+ number of ½grid squares/2 or use of rectangles (l×b) or triangles (½ b×h). Direction Course upon which something is pointing to. Methods of Showing Direction Traditional Methods 1. Use of Stars E.g. use of groups of stars called plough to find northern direction by locating the pole star and use of Southern Cross by using the brightest star which is over South Pole to find northern direction. 2. Use of Shadows E.g. morning, shadow of flag pole cast to your left you are facing north, etc. Land Marks Using conspicuous features such as hills, buildings even roads to get direction. Modern Methods 1. Land Marks 2. Compass Direction. Use of magnetic compass which has a needle which always points north. It has 16 cardinal points and 4 are basic. Bearing –Expression of direction in degrees of an angle. It’s measured from north in a clockwise direction. Calculation of Bearing Draw N-S line through observation point. Join the two points. If it’s a feature the line should end at the centre of that feature. Using a protractor measure the angle between the N-S line and the line joining the 2 points in a clockwise direction. Bearing is expressed in degrees, minutes and seconds. 1◦=60’(min), 1 min=60” (sec) The degrees are always expressed in 3 figures e.g. 030◦ Types of Norths True North -Position on the globe where all longitudes meet or the direction of N. Pole. Grid North -Point where Eastings meet at the N. Pole. 3. Magnetic North -Point which the magnetic needle rests when left to swing freely. Types of Bearing 1. Grid Bearing Bearing calculated from Grid North. Join the two points on the topographical map using a line. Measure the angle where the Eastings intersect the line joining the two points e.g. 030◦. True Bearing Bearing calculated from True North. Its calculated when the type of bearing isn’t specified. E.g. from our compass diagram true bearing will be 30◦-1’=29◦59’ Magnetic Bearing Bearing calculated from Magnetic North. Position of Magnetic North changes slightly every year. Steps Years which have elapsed × Annual change. (No need if annual change is negligible). E.g. from our compass diagram annual change =(20091991)×4.8’=18×4.8’’=86.4’’=1◦26.4’ Add to the angle between the grid and magnetic bearing 1.e. 1◦26.4’+2◦30’=3◦56.4’ Add to the Grid bearing (if change is towards E) or Subtract (if change is towards W). 30◦ +3◦ 56.4’=33◦56.4’ Location of Places

Process in which solid, liquid or gaseous materials are forced out of the interior of the earth into the earth’s crust or onto the earth’s surface. These materials are magma, lava, gases, dust, ash and cinder. Causes of Vulcanicity Magma under high temperature and pressure moving through lines of weakness or faults. When tectonic plates move away from each other and boundaries give way to magma. Underground water coming into contact with hot materials hence changing into gaseous form. There are 2 types of Vulcanicity: Extrusive Vulcanicity (volcanic): in which materials intrude crustal rocks and don’t reach the earth’s surface. Magma is the molten material while it’s underground. Intrusive Vulcanicity (plutonic): in which materials reach the earth’s surface. Lava is the molten material after it reaches the surface. There are two types of lava and magma, acidic and basic. Acidic lava is viscous and solidifies quickly and doesn’t spread far but accumulates around the vent. Basic lava is more fluid or less viscous and takes longer before cooling and spreads for great distances before doing so. Other materials emitted are gases, ashes, dust and cinder. The solid materials are called pyroclasts. Materials come out through a hole/vent (vent eruption) or crack/fissure (fissure eruption). Features Resulting From Vulcanicity -Divided into intrusive and extrusive features or landforms. Intrusive/Plutonic Features Features formed by intrusive Vulcanicity when materials intrude the earth’s crust. Sill An igneous intrusion which lies along a bending plane of rock strata. -Formed when magma forces its way between rock layers then cools and solidifies. It forms ridge like escarpments when exposed by erosion e.g. Fouta Djalon highland of Guinea and 3 sisters of S. Africa. Dyke A wall-like igneous intrusion which lies across the bedding plane of rock strata. -Formed when magma intrudes cracks or faults cutting across bedding planes of rocks then cools and solidifies. Can be vertical or inclined. When exposed it forms ridges e.g. Kaap Valley in Transvaal S. Africa and Jos Plateau in Nigeria. Laccolith A mushroom-shaped igneous intrusion lying between bending planes of a country rock. Formed when viscous magma pushes its way through a vent and accumulates around the vent before reaching the earth’s surface pushing the overlying rock into a dome shape. Its so high that land is turned into mountains e.g. El Koub Hill in Algeria, Henry Mountains in Utah U.S.A and Fonjay Massif in Madagascar. Batholiths Largest igneous intrusion formed underground formed when very hot magma intrudes bedding planes of rocks and replaces or metamorphoses it e.g. Chaila Massif in Gabon, Ikhonga-Murwe in Kakamega and the largest is in British Columbia. Lopolith a large saucer shaped igneous intrusion formed when viscous magma intrudes into bedding planes of a country rock. They form shallow depressions on the earths surface of the earth e.g. Bushveld complex in S. Africa and Duluth Gabbro mass in U.S.A. Phacolith A lens shaped igneous intrusion which forms in the crest or trough of an   anticline e.g. Corndon Hill in England. Extrusive/Volcanic Features Formed when magma reaches the earth’s surface through vents or fissures. Volcanoes A volcano is a cone shaped hill formed when volcanic materials flow out and accumulate around a vent. Volcanoes are classified into three groups: Active volcano- which is known to have erupted in recent times e.g. OL donyo Lengai in Tanzania and Mt. Cameroon, and Mauna Loa in Hawaii. Dormant volcano-not known to have erupted in the recent past but show signs of volcanic activity such as presence of hot springs, geysers and fumaroles e.g. Mt. Kilimanjaro, Longonot and Menengai. Extinct volcano-which has not shown signs of possible future eruptions e.g. Mountains Kenya and Elgon. Types of Volcanoes Acidic Lava Domes A steep dome shaped volcanic hill made of acidic lava. Viscous lava flows out through a vent. It accumulates around the vent because it’s viscous. Eruptions occur later and lava flows out covering the layers below. A steep sided dome shaped mound of volcano is formed e.g. Itasy Massif of Madagascar, Mt. Kenya and Kilimanjaro. Characteristics Its dome-shaped Has steep slopes Made of acidic lava Has lava layers Has steep slopes Has a narrow base Basic Lava Domes/Shield Volcanoes A low lying volcanic hill made of basic lava. Basic magma flows out to the surface through a vent. The lava flows far before solidifying because its fluid. Eruptions occur later and lava spreads over the old lava. A shield shaped mound of volcano is formed e.g. Canary Islands, Cape Verde and Sao Tome which are volcanic Islands in the Indian Ocean. Characteristics Dome/shield shaped Has gentle slopes Made of basic lava Has lava layers Has a broad base Ash and Cinder Cones A volcano built from ash and cinder or small fragments of lava. Violent vent eruption occurs. Ash and pyroclasts are emitted and thrown high. Some materials fall and settle around the vent forming a hill. Light materials are blown by wind to the leeward side e.g. Chyulu Hills, Teleki and Likaiyu near L. Turkana. Characteristics Made of pyroclasts Asymmetrical about the axis Cone shaped Has smooth slopes Has steep windward slope and gentle leeward slope Composite /Complex/Stratified Volcanoes A volcano made of alternating layers of lava and pyroclasts and conelets. The first eruption throws out pyroclasts. Then viscous lava flows out and solidifies on them. Eruption occurs later blowing the rocks sealing the vent. The pieces of rock settle on earlier solidified lava. Another mass of lava flows out and spreads over pyroclasts and solidifies. The process is repeated causing the volcano to build upwards The conelets are formed when magma is unable to overcome the plug and finds its way through weak lines at the sides and then pyroclasts and lava accumulate around the side vent e.g. Mountains Kenya, Longonot, Elgon and Kilimanjaro. Characteristics Cone shaped Stratified (made of alternating layers of lava and pyroclasts. It has conelets (parasitic cones). It has steep slopes. Made of acidic lava  Plug Dome/volcano/Spine A column of very viscous lava which sticks above the ground. A column of very viscous magma flows

Faulting is the cracking/fracturing of the brittle crustal rocks due to tectonic forces. Faults are fractures or cracks that develop in the crust. When tensional forces cause crustal rocks to stretch and fracture at the region of maximum tension. When compressional causes squeezing of crustal rocks to fracture at the areas where they are intensely squeezed. When vertical movements exert pressure on rocks leading to fracturing. When shear forces cause crustal rocks to tear. Upthrow-part of the land displaced upwards. Down-throw-part of the land displaced downwards. Throw-vertical displacement. Heave-horizontal displacement Hade-inclination of fault to vertical plane Fault line-fault path Fault plane-separation of land created by the fault Types of Faults Normal Faults Type formed by tensional forces in which one block slides downwards in relation to the other. Rocks are subjected to tensional forces A normal fault develops One block slides downwards. Reverse Fault Type formed by compressional forces in which one block of land is pushed upwards in relation to the other. Rocks are subjected to compressional forces. Type formed by shear forces in which adjacent blocks of land slide past one another. If a shear fault occurs between continents it’s called a Transform fault e.g. San Andrean fault of California and great glen fault of Scotland. Type formed when very strong compressional forces cause almost horizontal faults to develop and one block of land is pushed over the other. Type formed when anticlines are compressed further and cracks form on the crest. Steep line of slopes formed by vertical movement of earth along a fault e.g. Mau, Nguruman, Nyandarua and Nandi.   Are exposed parts of a fault plane. It may be formed due to normal faulting or reverse faulting when overhanging blocks are eroded. Fault Steps Land resembling the staircase or steps of a house with a series of fault scarps at different levels. Parallel vertical faults develop. Land between the faults is unequally displaced downwards. A series of fault scarps at different levels is formed. -E.g. Keiyo escarpment and at Kijabe. Blocks of land raised above the surrounding land. Where tectonic forces cause faulting and land on one side of the fault get raised or sink along the fault planes. Examples of fault blocks are Aberdare/Nyandarua ranges, Mau escarpment and Nandi Hills. Where Blocks of land bordered by normal faults which are almost parallel to each other sink leaving the middle block standing. Examples of horsts are Ruwenzori of W. Uganda and Usambara and Pare mountains of Tanzania. Tilt Blocks -Fault blocks which are inclined on one side. Occurs when the fault block, horst or fault steps have greater uplift on one side and as a result they are not flat at the top but tilted. The resultant features are tilted fault blocks, tilted horst and tilt fault steps which form ridges and fault guided valleys. Along narrow trough with steep escarpments on both sides. Theories of Formation Tensional Theory  Rocks are subjected to tensional forces. Compressional Theory Rocks are subjected to compressional forces. Overhanging blocks are worn out by denudation to form escarpments Suggests the rift valley was formed by Anticlinal arching. Upward forces pushed sedimentary rock strata upwards. The rock layers bent into a big arch. A gaping/huge crack developed at the crest of the arch due to tension forming the rift valley. The Great Rift Valley/The Great E.A Rift Valley The world’s biggest rift valley. It starts in Syria and ends in Mozambique. It’s divided into 4 parts. Ethiopian Rift system-starts from Afar in Ethiopia to the Kenyan border around L. Stephanie. Gregory Rift system-Starts from the northern border of Kenya with Ethiopia to Tanzania. It has a small N.E-S.W branches: Kano Rift valley in Kenya Eyasi Rift Valley in Tanzania Western Rift valley-Starts at Sudan border to south of L. Rukwa. Features which are here are Ruwenzori Mountain and Lakes Albert, Edward, Kivu, Tanganyika and Rukwa. Malawi Rift valley-a continuation of Gregory Rift system to Zambezi River in Mozambique. It has a small N.E-S.W branch called Luangwa valley. The Gregory Rift Valley Named after a geologist called Gregory J.W who carried out extensive studies in this area. It’s where the Rift Valley features are more pronounced. Features associated with it Fault blocks–Aberdare range, Mau, Nandi and Cherangani hills. Step faults-Kijabe and Tambach Tilt blocks-Aberdare range uplifted and tilted eastwards and Mau escarpment uplifted and tilted westwards. Lava flows and volcanic cones e.g. Menengai and Ngorongoro crater. Rift Valley lakes formed when unequal sinking created faults which were later filled with water. The lakes are deep and elongated. Examples are Lakes Naivasha, Nakuru, Elementaita, Baringo, Bogoria, Ol Bolossat and Turkana. Most of the lakes are salty with exception of L. Naivasha which has fresh water. Why Most Rift Valley Lakes Are Salty Lack of outlets to drain away salts contained in them. Lack of enough water to dilute salinity due to little rainfall and lack of rivers flowing in them. High rates of evaporation causing increased accumulation of salts. Lake’s water being in contact with rocks with mineral salts which it directly dissolves. Washing into the lake of mineral rich soils by surface runoff.  Why L. Naivasha Has Fresh Water It has underground drainage to the Indian Ocean. There is inflow of fresh water from rivers and rain. The latest volcanic eruption covered the bed rock with lava. Major Faulted Areas of the World The Great Rift Valley from Syria to Mozambique. Northern England and the Great Glen Fault of Scotland. The Central Massif of Europe. The middle Rhine Rift Valley region. Significance of Faulting To Human Activities Rift valley lakes are important for fishing, irrigation and domestic use. The Rift Valley and associated features are a tourist attraction which earns foreign exchange. Hot springs and geysers formed during faulting can be harnessed for geothermal power. Block Mountains are water catchment areas and sources of rivers due to the heavy rainfall they receive on the windward side. Faulting results in the exposure of minerals such as diatomite in Gilgil and Fluorspar in

Process in which crustal rocks are distorted by compressional forces by being caused to bend upwards and downwards. It occurs on fairly young sedimentary rocks. Anticlines (upfolds)-parts of the earths surface which bend upwards when folding occurs. Synclines (down folds)-Parts of the earths surface which bend downwards when folding occurs. Crest-upper most part of Anticline. Trough-lowest part of a syncline Limp-rock layers sloping on both sides of a fold Axis-imaginary line drawn vertically through the centre of the anticline.   Which are symmetrical about the anticline. Formed by 2 compressional forces of equal magnitude. 2.Asymmetrical Folds Which are asymmetrical about the anticlines axis or in which one limp is steeper than the other. Formed by two compressional forces of unequal magnitude in which one is stronger than the other. In which anticline of one fold is pushed over the limp of the other.                                             4.Isoclinal Folds Which are packed closely together and with limps almost parallel to each other. Vertical Isoclinal folds are formed by compressional forces of equal magnitude while inclined Isoclinal folds are formed by forces of unequal magnitude. Which lie in a horizontal manner. Formed by two compressional forces one of which is very strong. In which one limp is pushed over the other limp. The forces are very strong and they cause a fracture/fault to develop. Folds characterised by minor upfolds and minor downfolds. Land is first subjected to weak compressional forces resulting into minor folds. Later the land is subjected to much greater compressional forces resulting into new upfolds with minor folds (Anticlinorium) and new down folds with minor folds (Synclinorium). Resultant Features Due To Folding 1.Fold Mountains and Their Distribution -Worlds highest and most impressive mountains and the most conspicuous feature of folding. Himalayas-Asia Rockies-W.N. America Everest-Nepal-Tibet border- Atlas-N.W. Africa.  highest point. Appalachian-E.N. America Andes-Peru in S. America Alps-South Central Europe  Theories of Origin of Fold Mountains 1.Contraction Theory During the earth’s formation surface rocks cooled faster and wrinkled to form Fold Mountains. 2.Convectional Currents Theory Horizontal convectional currents in the mantle exerted frictional pull on crustal rocks. Continental crusts were pulled towards each other. Sediments between them were squeezed into folds. 3.Continental Drift Theory During break of Gondwanaland India drifted northwards and collided with Eurasia. Sediments between were squeezed to form fold mountains e.g. Himalayas and Everest. 4.Plate Tectonics Theory When an oceanic plate meets another or it meets a continental plate the sediments under the sea are compressed to form Fold Mountains. When two continental plates meet the sial layer is compressed to form fold mountains -E.g. Alps was formed when Africa plate pushed against the rigid European plate. A relatively continuous line of steep slopes facing the same direction. Formed one compressional force causes folding resulting in one steep limp of the anticline which forms the escarpment. Formed when not very strong forces cause folding causing some parts of the earths surface to form synclines forming basins. When folding occurs anticlines form uplands/ridges/hills while synclines form valleys. Plains which appear to rise and roll. Formed when plains are acted upon by weak compressional forces resulting into gently sloping anticlines and very wide synclines. A high fairly level land between mountains. Formed when rocks at the edges of a region become intensely folded and the middle parts resist folding resulting into mountains which enclose a high fairly level land. 7.Inter-montane basins -Formed when some parts of inter-montane plateau sink more to form basins. Significance of Folding To Human Activities/Economic significance Positive/advantages Fold Mountains are a tourist attraction which brings foreign exchange. Fold Mountains are water catchment areas and sources of rivers. Some fold mountains have valuable mineral deposits such as coal and petroleum. Fold Mountains act as protective barriers during war. Some fold mountains on the path of rain bearing rainfall influence rainfall causing the windward slopes to receive heavier rainfall. Folding can lead to formation of valuable minerals due to metamorphism. Folding brings valuable minerals to the surface making them easily available. Negative/disadvantages Fold Mountains on the path of rain winds cause the leeward slopes to receive less rainfall. Fold Mountains discourage settlement due to cold temperatures and rugged terrain Folding can lead to burying of minerals. Fold Mountains are a barrier to road and railway where there are no passes and where there are passes they may be covered by snow. Orographic fog hinders pilot’s visibility. To Physical Environment Folding can result in submerged coastal zones which are used as harbours. Can lead to metamorphism of rocks changing their original state and making them more resistant to erosion. Depressions formed by folding turn into wet land important for water purification. Folding leads to faulting and magma may escape through faults leading to Vulcanicity and earth quakes.