Final answer:
The pair of numbers in a grid reference on a map corresponds to the lower-left corner of the square. Latitude and longitude are used to define positions on a grid system, which is crucial for precise geographical localization.
Step-by-step explanation:
Understanding Grid References on Maps
When reading a grid reference number corresponding to a grid on a map, you read the pair of numbers corresponding to the lower-left corner of the square. This method of identifying positions on maps is crucial for accurately locating geographical points on the Earth’s surface using a grid system.
A grid system, such as one based on latitude and longitude, enables geographers and navigators to pinpoint any location on Earth. Latitude measures how far north or south a point is from the Equator, while longitude measures how far east or west a point is from the Prime Meridian. Together, these two sets of lines create a network known as a graticule on maps, allowing for precise location measurements.
The United States Geological Survey (USGS) publishes topographic maps that are defined by quadrangles, showing detailed land elevations and features. Their borders are defined by lines of longitude and latitude, and when looking at the grid on these maps, the referenced coordinates are read horizontally from left to right to find longitude and vertically from bottom to top to find latitude. This system is fundamental in navigation, surveying, and property planning, illustrating the impact of grid patterns on both physical landscapes and cultural practices.