How to Read Latitude and Longitude on a Map: 11 Steps

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How to Read Latitude and Longitude on a Map: 11 Steps
How to Read Latitude and Longitude on a Map: 11 Steps
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Latitude and longitude are measurements used to describe the location of a particular place on the globe. That way, after learning to read and interpret them on a map, you can determine the geographic coordinates of any point on the planet. While online maps make it easy to determine these measurements, knowing how to find them manually can be extremely helpful in some situations. To read latitude and longitude correctly, you must first understand the basic concepts behind these measurements. Next, you need to learn how to identify latitude and longitude markers on a map and define the exact locations represented by a coordinate.

Steps

Part 1 of 2: Understanding Latitude and Longitude

Read Latitude and Longitude on a Map Step 1

Step 1. Familiarize yourself with the concept of latitude

Latitude is a measure of the distance to the north or south of the equator, which is located at the midpoint of the Earth between the two poles. The earth is divided into 180 lines of latitude, called parallels. 90 of them are north of the equator and the other 90 are south.

Read Latitude and Longitude on a Map Step 2

Step 2. Learn the definition of longitude

Longitude is a measure of the distance to the east or west of an imaginary vertical line running through the center of the globe, from the North Pole to the South Pole, called the Greenwich meridian. There are 360 ​​lines of longitude, called meridians, 180 of them are located east of Greenwich and the other 180 are located west.

The meridian opposite the Greenwich meridian is called the Greenwich antimeridian

Read Latitude and Longitude on a Map Step 3

Step 3. Know the measurement units used for latitude and longitude

Latitude and longitude measurements are usually expressed in degrees (°), minutes (′), and seconds (″). The total distance from one parallel or meridian to another is 1°. To produce even more accurate measurements, each degree can be subdivided into 60 minutes and each minute into 60 seconds (thus each degree has a total of 3600 seconds).

Latitude and longitude are measured in degrees rather than absolute units of measurement (such as miles or kilometers) because the Earth is spherical. Although the distance between degrees of latitude is constant (approximately 111, 12 km), the shape of the Earth causes the distance between degrees of longitude to decrease as it approaches the poles

Read Latitude and Longitude on a Map Step 4

Step 4. Measure the latitude and longitude in relation to the starting point

When measuring latitude in any direction, the Equator is considered the starting point, at 0° latitude. Likewise, the Greenwich meridian is the starting point for longitude measurements, representing 0° of longitude. Each measure of latitude or longitude is expressed in terms of distance from the point of origin, regardless of direction.

  • For example, the North Pole is at 90° N, which means it is 90° north of the equator.
  • The Greenwich antimeridian is 180° east or west (there is no difference in this case) of the Greenwich meridian.
  • The Great Sphinx of Giza in Egypt is located at 29°58′31″ N and 31°8′15″ W. As such, it is less than 30° north of the equator in latitude and approximately 31° east of the Greenwich meridian in longitude.

Part 2 of 2: Determining Latitude and Longitude Coordinates on a Map

Read Latitude and Longitude on a Map Step 5

Step 1. Find a map that displays the latitude and longitude lines

You are more likely to find this information on maps of large areas or on smaller maps designed to accurately reproduce terrain, such as topographical maps. On the internet, it is possible to search and find this type of map with some ease.

Read Latitude and Longitude on a Map Step 6

Step 2. Check the location you are interested in

Take a look at the map and locate the area whose coordinates you want to know. Mark the exact spot with a pin or pencil.

Read Latitude and Longitude on a Map Step 7

Step 3. Locate the latitude and longitude markers

Latitude is indicated on a map by a series of evenly spaced horizontal lines running across the map, while longitude is indicated by a series of evenly spaced vertical lines running from top to bottom. Look for numbers along the edges of the map that represent the coordinate of each line.

  • Lines of latitude are marked along the east and west edges of the map. The longitude ones are marked on the north and south edges.
  • Depending on the scale of the map, coordinates may be represented in fractions of degrees instead of whole degrees. For example, there might be a coordinate represented every minute within a degree instead of just every degree (for example, 32° 0′, 32°1′, and so on).
  • The map should also indicate where the described latitude and longitude are in relation to Equator and Greenwich (for example, north or south, east or west).
  • Be careful not to confuse latitude and longitude lines with UTM lines, which represent another type of coordinate system that can be found on maps. UTM numbers are usually marked in smaller text (and no degree symbols) and have lines that are a different color than the latitude and longitude lines.
Read Latitude and Longitude on a Map Step 8

Step 4. Use a ruler to mark the latitude of your point

Take a ruler and pencil and draw a horizontal line that connects your point to the east or west edge of the map, parallel to the nearest latitude line.

Read Latitude and Longitude on a Map Step 9

Step 5. Draw another line to mark the longitude of the point

From the same point, use the ruler and pencil to draw a straight vertical line to the north or south edge of the map, parallel to the nearest longitude line.

Read Latitude and Longitude on a Map Step 10

Step 6. Estimate the latitude and longitude of your point using the coordinates on the map

Depending on the scale of the map, you can even estimate seconds. Note where your latitude and longitude lines intersect the coordinate lines at the edge of the map and calculate the approximate position of the point.

  • If the map shows seconds, find the second measurement closest to where the lines you made intersect the latitude or longitude scale at the edge of the map. For example, if your latitude line is about 5″ above the 32°20′ N line, your point will be at a latitude of approximately 32° 20′5″ N.
  • If the map shows minutes but not seconds, you can estimate your latitude or longitude by dividing the space between each line by 10, where each division is six seconds. So if its longitude line falls about 2/10 to the left of the 120°14′E line, then the longitude is approximately 120°14′12″E.
Read Latitude and Longitude on a Map Step 11

Step 7. Gather measurements to determine coordinates

Geographic coordinates are where the lines of latitude and longitude converge at a single point. Look at the numbers you got for the latitude and longitude of your point and put them together (eg 32° 20′5″ N, 120°14′12″ E).

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