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Social Studies Geographic Fundamentals Review Geographic Basics Continents There are seven continents – North America, South America, Europe, Asia, Africa, Australia and Antarctica. Geographers describe continents as large continuous bodies of land. Greenland is sometimes described as an island continent but it is not a true continent The Caucasus Mountains are the general boundary between Europe and Asia. Hemispheres The term hemisphere means half a sphere. The earth is divided into a northern hemisphere and a southern hemisphere. These two hemispheres are divided by the equator. There is also an eastern hemisphere and a western hemisphere. The prime meridian or Greenwich meridian divides the eastern and western hemispheres. Cardinal Directions The four cardinal or main directions are north, east, south and west. There are also four intermediate directions which are points halfway between each pair of cardinal directions. The intermediate directions are NE, SE, SW and NW. Map Basics To be useful a map should have A Title A Legend Scale Maps use many symbols to illustrate the various features depicted. A Map Legend Map Projections Map Projections The earth is round or three dimensional but maps are flat or two dimensional. To transfer any portion of the earth’s spherical surface to a flat map a map projection must be used. There are many different types of map projections. Map Projections II A projection may be “equidistant” and preserve the accuracy of distances or directions from any point. “Conformal” projections preserve directions at any point on the surface of the earth. “Equal area” projections preserve the size of any area on the globe. There are projections which do not do any of these things. Map Projection Of Canada Map Projections III The type of projection used will depend on several factors including the purpose of the map. The Mercator projection is one of the most famous projections. It has long been popular because it produces a rectangular map but it tends to distort areas of the globe located at high latitudes. Map Projection of the World using a Cylinder Map Scale Map Scale Map scales allow geographers to relate the distance on a map to actual distance on the surface of the earth. For example if 3 cm on a map represents 1 km on the ground then the scale would be Line Scale This type of scale appears as ruler or bar on the map. In the example each interval or space along the ruler stands for 10 km on the earth’s surface. A piece of paper can be used to mark the distance between two places on a map and then applied to the line scale for measurement. Representative Fraction Representative Fraction or RF scale is expressed as a ratio. RF scale is very useful because it applies easily to any units of linear measurement so it can be used for yards, meters or feet. An RF of 1:25,000 means that one unit of measure on the map is equal to 25,000 of that same unit of measure on the ground. Using metric units an RF of 1:2,000 means that one cm on the map represents 20 meters on the ground. Detail and Scale Small scale maps do not show very much detail. Large scale maps are very detailed. An RF of 1:40,000,000 would be a small scale map and not detailed. Whereas an RF of 1: 2,000 would be a large scale map and very detailed. Latitude and Longitude Earth Grid An earth grid is a series of lines on the surface of the globe which are used to locate places and objects. A simple grid uses horizontal and vertical parallel lines which can be numbered or lettered. The grid position of the object is 6E. Military Grid Reference System This rectangular grid appears on topographic maps. The numbers identify horizontal and vertical lines. To locate the circle the line to the west (91) is used first, followed by the line to the south (94). The reference square for the circle is 9194. Military Grid Reference System II A more precise reference for the circle can be obtained by dividing the reference square into 100 smaller squares. The circle is 5/10 of the way between lines 91 and 92 and 6/10 of the way between lines 94 and 95. The exact location of the circle is 91(5) and 94(6) or 915946. Latitude and Longitude Latitude and longitude form a slightly more complex earth grid which has specific application on the spherical surface of the globe. The earth rotates around an imaginary axis which if extended become the north and south poles. An imaginary line drawn on the earth’s surface connecting all points that are exactly halfway between the poles is called the equator. Latitude It is from the equator that all lines of latitude are measured 90 degrees north and south to each pole. The equator is a great circle because it divides the earth into two equal parts. The shortest distance between any two locations on the earth’s surface is a great circle. Latitude II A line connecting points of equal latitude is called a parallel of latitude. This line is parallel to the equator and to all other lines of latitude. Longitude Lines of longitude are drawn through the north and south poles to intersect with lines of latitude. The Greenwich meridian or prime meridian is the line of longitude from which all other lines are measured – east and west – around the globe. Lines of longitude are measured from 0 degrees at the prime meridian to 180 degrees at another line called the International Date Line. Meridians of longitude are not parallel to each other because they converge at the poles. Latitude and Longitude With this grid system any point on the earth’s surface can be accurately located in degrees, minutes and seconds. Each degree contains sixty minutes and each minute sixty seconds. The latitude and longitude of Vancouver, British Columbia is 49 13N 123 06W. Time Time Zones Time zones are organized so that most places in the world have the sun at its highest point in the sky at noon. The earth rotates 15 degrees of longitude each hour which allows the world to be divided into 24 time zones (15 X 24 = 360). All time zones are measured from the prime or Greenwich meridian. At the Greenwich meridian the time is described as GMT or Greenwich Mean Time. Time Zones II Greenwich Mean Time is sometimes described as Universal Time and useful for airlines and other organizations wishing to use only one standard time. The International Date line is located on the opposite side of the globe from the Greenwich meridian. Not all time zones follow exactly the 15 degree divisions around the world. Political and administrative considerations often result in modifications to this system. Time Zones II In Canada we have several standard time zones. In British Columbia we use Pacific Standard Time which is 8 hours ahead of GMT. When it is noon in Vancouver it is already 8 PM on the Greenwich meridian. Our time zone is called zone + 8 so we must subtract 8 hours from GMT to determine our time. Daylight-Saving Time Daylight-saving time is used to make a small adjustment to daylight hours in the summer to conform to the time when people are awake. Usually the clock is advanced one hour on the first Sunday in April and set back one hour on the last Sunday in October. The phrase “spring forward, fall back” helps us to remember which way to set our clocks. Topographic Maps Topographic Maps Topographic maps provide the geographer with images of data related to the surface of the earth. A topographic map provides a three dimensional picture of a portion of the earth’s surface on a flat map. In addition a topographic map shows all of the human alterations to the natural environment such as roads, railways and cities. Contour Lines Topographic maps are standard maps used for most navigation on the earth’s surface. On these maps contour lines are continuous lines marking all points of the same elevation All points on a contour line are at the same height above sea level. Contour Lines II Contour lines which are close together represent a steep slope. Widely spaced lines indicate a gradual slope. Contour lines form a V pattern crossing a stream and the V always points upstream. A U shaped contour line points downhill. Contour Lines III A profile across a topographic map may obtained by drawing a line between two points; X and Y. The profile can then be drawn as illustrated in the diagram. Contour Lines IV This topographic map shows a small area of Poland. Note the contour lines which are found along the river in the centre of the map. Because the lines are close together they show a valley with fairly steep sides. Graph Skills Circle Graphs Circle graphs are used to show the relationship between a whole thing and its various parts. These graphs are sometimes referred as pie charts or graphs This graph shows the percentage of the population speaking English, French and other languages in a small community. Languages Spoken Bar Graphs Bar graphs use columns to show a relationship between two or more ideas. They allow visual comparison of the parts of something with the whole. SCHOOL GROWTH 1999-2001 2000 1500 1000 500 0 1999 2001 Line Graphs D ry ua br ec em be er ob ct 8792 80 72 r 62 85 Fe 100 80 60 40 20 0 O The lines on a line graph show how things grow in number or size. The can also allow us to project the trend of growth by extending the line in the general direction of its movement. Average Test Marks Climate What is climate? Weather is what happens on a daily basis. It may rain, snow or be sunny and clear. Climate is the average of weather conditions over an extended period of time. Just like the weather climate is highly variable. Climate It is common to use July and January as months in which climate is compared. The highest temperatures in the northern hemisphere are usually reached in July. In January temperatures are generally at their lowest. Temperature Maps The lines on the map in the diagram are called isotherms because they connect places with the same average temperature. The spaces between each isotherm are zones which are coloured to allow a clearer view of the area of similar temperature. Average July Temperatures Climate Graphs Climate graphs show the average annual temperature and precipitation figures for any selected place. The line graph is used to show the temperature for each month from January on the left to December on the right. The bar graph shows the precipitation for each month. 120 25 20 100 15 80 10 5 60 0 40 -5 -10 20 -15 0 -20 J F M A M J J A S O N D Climate Controls - Latitude Temperature is affected by latitude. The farther north or south of the equator the colder it will generally be. This is because the sun’s rays cover a larger area in the higher latitudes. In the lower latitudes near the equator the sun’s rays are more direct and cover a smaller area. Climate Controls – Ocean Currents Three ocean currents affect Canada. The warm Alaska Current sweeps across the North Pacific onto the coast of British Columbia. The cold Labrador Current comes out of the Arctic and extends down the coast of Atlantic Canada. Finally, there is the warm Gulf Stream which originates in the Caribbean Sea and flows north to moderate the Labrador Current. Each of these ocean currents has an important role to play in regulating weather conditions on the coasts of Canada. Climatic Controls – Air Masses Air masses tend to have the same average temperature and level of moisture. These factors are determined by where the air originated. Arctic air masses tend to be cold and dry whereas Pacific air masses are warm and moist. Air masses take with them these climatic conditions and in turn influence the areas into which they move. Climatic Controls Elevation Air cools by one degree Celsius for every 100 meters of elevation. This is because it expands as it rises and, as a result, loses heat. A relative humidity of 100% reduces the rate of cooling as water vapour condenses to form water. Climatic Controls - Relief Relief is the variation in elevation on the surface of the earth. High mountains block the movement of air masses. On the west coast of Canada the Coastal Mountains force warm moist Pacific air to rise. Climatic Controls – Relief II On the windward slope this becomes rain or snow but on the leeward slope the warm air retains moisture and it is dry. We call this the “rainshadow” effect. Relief rain is called orographic percipitation. Climatic Controls – Proximity of Water Large bodies of water have the effect of moderating land temperatures keeping temperatures cool in summer and warmer in winter. Regions which are close to oceans or large lakes will also tend to receive more precipitation because air masses will absorb the moisture. Climatic Controls – Proximity of Water II We call climates which are removed form the influence of bodies of water “continental.” Regions close to large bodies of water will have “maritime climates.” Conclusion Geography Geography is a study of basic skills which can be applied to the use of maps and globes. It is also a study of the interaction of the earth and the natural forces which act upon it.