Geographical Measurements and Calculations

Latitude Measurements

• Distance of 1 degree of latitude: 110.58 km (68.71 miles) at the equator.
• Distance of 1 degree of latitude: 111.7 km (69.41 miles) toward the North Pole.
• Estimated average distance of 1 degree of latitude: 111 km (69 miles).
  • Quick estimation: 100 km per degree for mental calculations.

Approximation Symbol

• The tilde sign (~) indicates an approximation in calculations.

Distance Calculation Example

• Distance from Equator to 10° North:
  • Calculation: $111 ext{ km} imes 10 = 1,110 ext{ km}$

Dimensional Analysis

• Used to convert known quantities (e.g., inches to centimeters).
• Important to keep track of units.

Example Calculation for Distance to 40° North

• Given 40 degrees latitude:
  • 40 ext{ degrees} imes rac{111 ext{ km}}{1 ext{ degree}} = 4,440 ext{ km}
• If using miles: $40 ext{ degrees} imes 69 ext{ miles} = 2,760 ext{ miles}$
  • Convert miles to kilometers using: $0.62 ext{ miles per } 1 ext{ km}$

LSU Distance Calculation

• LSU at 30.4° North:
  • Distance from Equator: $30.4 ext{ degrees} imes 111 ext{ km/degree} = 3,384.4 ext{ km}$

Distance to Tropic of Cancer

• Tropic of Cancer at 23.5° North:
  • Distance: $23.5 ext{ degrees} imes 111 ext{ km/degree} = 2,608.5 ext{ km}$

Example from Tropic of Cancer to Arctic Circle

• Arctic Circle at 66.5° North:
  • Degrees between Tropic of Cancer and Arctic Circle: $66.5 - 23.5 = 43 ext{ degrees}$
  • Distance: $43 ext{ degrees} imes 111 ext{ km/degree} = 4,773 ext{ km}$

Longitude Considerations

• Distance between degrees of longitude varies:
  • At equator: 111 km per degree.
  • Converges to 0 at poles; estimation only valid near equator.
• Latitude lines: parallel and equidistant.
• Longitude lines: converge; not consistent distance between.