Coordinates: Latitude & Longitude

Map coordinates may be expressed in different formats (UTM, etc.). The concept of a point location on earth using latitude and longitude only is presented here. There are lots of other online resources that will assist you with the use of UTM cooridnates. The UTM (Universal Transverse Mercator) is a system of coordinates that describes position on a map. GPS receivers can display locations in UTM coordinates if that is what you prefer/need. Most maps, especially those for hikers, display UTM coordinates. They are used by Search and Rescue operators and are even becoming more common in guidebooks. If you want more information pertaining to UTM, check the How to Read UTM Coordinates at wikiHow. Below is The UTM Grid video provided by wikiHow. Today I find myself using the latitude and longitude a bit more than UTM.



Let's use the Bruce Trail as an example. The Bruce Trail crosses the 21st Sideroad [Blue Mountains Map 24, Ed 28.0] in the Beaver Valley section at approximately 44.511710, -80.380860 [same as 44°30'42.2"N 80°22'51.1"W]. Also, there is a recommended parking location at approximately 44.513039, -80.374948.  For this example I will use the first set of coordinates (44.511710, -80.380860) that is the approximate location where the Bruce Trail crosses the road.

Latitude & Longitude Globes

First number > Latitude

The number 44.511710o is called the latitude and is shown in decimal degrees (no minutes & seconds). The degrees latitude is the location of the given spot north of the reference. For latitude the reference is the equator or 0o latitude. So the spot is 44.511710o north of the equator. Lines of latitude run east-west but measure north or south of the equator. The lines are sometimes called "parallels".

 Second number > Longitude

The number -80.380860o is called the longitude and is shown in decimal degrees here. The degrees longitude is the location of the given spot west of the reference. For longitude the reference is the 0o longitude or the prime meridian. The prime meridian is the circular line of longitude that passes through the Royal Observatory, Greenwich in southeast London, U.K. (also known as the Greenwich Meridian). So the spot is -80.380860o west of the prime meridian. Note that the longitude number is shown with a negative (minus) sign in front of it. The negative (minus) sign, in this case, means "west of". Lines of longitude run north-south but measure east (+) or west (-) of the prime meridian.


How to use the latitude/longitude numbers in Google Maps.

Step 1 - Open Google Maps in your browser.

Step 2 - Type (or copy/paste) the latitude/longitude into the Google Maps search form as shown in the image below.

Google Maps Search Form

Step 3 - Click the blue search button (magnifying glass).

Step 4 - Google Maps will display the location on the map at that latitude and longitude and display a pin. In the case of this screen capture (below) I had turned on the satellite layer for more detail. The trail passing south to north is faint in the image.

Google Maps Showing Spot

Step 5 - Zoom in to that location (pin) and RIGHT click the arrow and a menu pops up. Click the "What's here?" in the list. Watch the bottom , centre of your monitor screen and you should get a form similar to the one below.

Google Maps of Showing Spot

Step 6 - If you are familiar with how Google Maps works, you can use the Google Maps "Get directions" button to create driving directions to the location 44.511710,-80.380860.