Grade 8 Map Skills: Lines of Latitude and Longitude

Cape Town Map Codes and Coordinates

• The number 18 on the map code signifies a specific grid square or area within Cape Town.
• The number 33 represents another defined grid square or area on the map of Cape Town.
• Moving south on the map indicates an increase in minutes, showing a progression towards the South Pole.
• Moving east indicates a change in minutes, reflecting a journey towards the Prime Meridian and the International Date Line.
• The code '39 DC' refers to a specific cartographic or geographical designation in Cape Town, identifying a unique area.

Geographic Fundamentals

• The largest arc of latitude on Earth is the Equator.
• The Prime Meridian, designated as 0°, runs longitudinally and divides the Earth into east and west hemispheres.
• Lines of latitude run parallel to the Equator, encircling the globe horizontally.
• The Equator is established at 0° latitude.
• Degrees (°), minutes ('), and seconds (") are represented by respective symbols for accurate geographical measurements.

Latitude and Longitude Characteristics

• Lines of latitude are referred to as parallel arcs because they maintain consistent distances from each other and do not intersect.
• On a topographical map of Cape Town, moving from 55' to 59' latitude indicates a shift in northern or southern position.
• The International Date Line separates the Earth into 180° east and 180° west longitudinally.
• South African maps measure coordinates in a Southerly and Easterly direction due to geographical positioning relative to the Equator and the Prime Meridian.

Measurement Units and Map Scales

• In South Africa, there are 60 seconds in a minute when measuring geographic coordinates.
• The symbols for degrees, minutes, and seconds used are °, ', and " respectively.
• On a Cape Town topographical map, letters A to D and numbers 1 to 10 designate various grid sections for clarity and navigation.
• The main scale used for topographical maps in Geography is typically a ratio or representative fraction (e.g., 1:50,000).
• Kilometres in the metric system are denoted by the symbol 'km'.
• 'cm' stands for centimeters, indicating a metric unit of measurement for shorter distances.

Map Scale Types and Metric System

• A line scale on a map indicates actual distances on the ground, providing a visual representation of distances.
• A mnemonic for remembering metric system prefixes in order is "King Henry Died By Drinking Chocolate Milk," standing for kilo-, hecto-, deka-, base unit, deci-, centi-, milli-.
• The distance unit symbol for 'millimeters' is 'mm'.

Area Calculations and Conversions

• For a block with length L = 3 cm and breadth B = 4 cm, the area equals 12 square centimeters (not yet in square kilometers).
• When calculating area in hectares, values should be multiplied by 500/10,000 for conversion purposes.
• For Block C2 with length 5 cm and breadth 4 cm, the area calculated is 20 square centimeters.
• For Blocks D1 and D2 with lengths of 6 cm and breadth of 3 cm, the area in hectares needs conversion techniques, considering 1 hectare equals 10,000 m².
• To convert a measurement into hectares, divide the area in square meters by 10,000.