O Level History: Longitude and Latitude

Longitude and latitude are geographical coordinates that are used to determine a specific location on the earth’s surface.
They are measured in degrees, minutes, and seconds, and are used in various mapping systems to accurately locate places on the map.

The concept of longitude and latitude dates back to ancient Greece.
In the 2nd century BC, Hipparchus developed a system to measure the angle between the horizon and the stars to determine longitude and latitude.
Later in the 16th century, Gerardus Mercator developed the first map using longitude and latitude.

Latitude is the angular distance of a place north or south of the earth’s equator.
Longitude is the angular distance of a place east or west of the prime meridian.
Together, latitude and longitude provide a unique address for each location on the earth’s surface.
The equator is the starting point for measuring latitude, while the prime meridian is the starting point for measuring longitude.

To determine a specific location on a map, the latitude and longitude coordinates must be used.
The latitude is represented by horizontal lines, while the longitude is represented by vertical lines.
Each line of latitude and longitude represents a specific degree measurement.
For example, the coordinates for the Eiffel Tower in Paris, France, are 48.8584° N latitude, and 2.2945° E longitude.
Harare is located at latitude -17.82517 and longitude 31.03351.
These coordinates can be used to accurately locate the Eiffel Tower on a map.

Latitude and longitude are used in various mapping systems, including Google Maps and GPS devices.
They are used by pilots and navigators to determine their location while flying or sailing.
They are also used by scientists and researchers to track the movement of animals and study the Earth’s climate.

Find a map that shows the area you want to locate. This can be a physical map, political map, or any other type of map that includes latitude and longitude lines.
Locate the point you want to find on the map. You can do this by looking for recognizable landmarks, street names, or other features that you know the location of.
Find the latitude and longitude lines on the map. The lines are usually marked in increments of one degree, with the equator being the reference point for latitude and the prime meridian for longitude.
Determine the latitude of the point. Start by finding the line of latitude that the point is closest to. Estimate the fraction of a degree between that line and the point. For example, if the point is halfway between two latitude lines, it would be 0.5 degrees north or south of the equator.
Determine the longitude of the point. Start by finding the line of longitude that the point is closest to. Estimate the fraction of a degree between that line and the point. For example, if the point is halfway between two longitude lines, it would be 0.5 degrees east or west of the prime meridian.
Combine the latitude and longitude coordinates to get the exact location of the point. For example, the coordinates for Harare, Zimbabwe are approximately 17.8250° S, 31.0335° E.

Use a GPS device or map to find the location of the point in question.
Measure the distance between the point and the equator, either north or south, using meters.
Divide this distance by the length of one degree of latitude (approximately 111 kilometres or 111,000 meters) to determine the latitude in degrees.
Measure the distance between the point and the prime meridian, either east or west, using meters.
Divide this distance by the length of one degree of longitude at the latitude of the point (this varies depending on the latitude) to determine the longitude in degrees.
Record the latitude and longitude in the proper format (i.e. degrees, minutes, and seconds or decimal degrees).

Discover more comprehensive and exam-focused ZIMSEC Ordinary Level Geography Notes.