When we see a coordinate map We must know how to interpret it, as it can provide us with a wealth of information about the places it depicts. This map uses a geographic coordinate system, which refers to any point on the Earth's surface. To do so, it uses two angular coordinates: latitude and longitude.
If you want to know how to interpret a coordinate map and how important it is, this is your post.
What is a coordinate map
A coordinate map is one that uses a geographic coordinate system with two angular coordinates: latitude, which tells us north and south, and longitude, which tells us east or west. If we want to know the lateral angles of the Earth's surface with respect to the center of the Earth, we only have to align it with its axis of rotation.
To understand what a coordinate map is, we must understand some basic concepts. The first step is to understand what parallels are. The equator is an imaginary circle perpendicular to the Earth's axis of rotation. Therefore, it is a unique circle. Furthermore, it has the main characteristic that it is equidistant from the poles and is the one that divides our planet into two hemispheres. In the northern part, we have the Northern Hemisphere, which consists of a hemisphere stretching from the Equator to the North Pole. On the other hand, we have the Southern Hemisphere, another hemisphere stretching from the Equator to the South Pole. Antarctica is located at the South Pole.
Parallels exist both north and south of the Equator, representing a succession of circles smaller than the Equator. These circles are imaginary and become smaller as they approach the poles. The distance between each circle is the same, which is why they are known as parallels.
Particular parallels on a coordinate map
Let's describe the particular parallels on a coordinate map. The main ones are the Tropic of Cancer and the Tropic of Capricorn. These two parallels mark the northernmost and southernmost points of the Equator. These are the places where the sun's rays fall vertically. In other words, they are the most extreme latitudes the sun can reach in its apparent annual motion.
Therefore, we know that the summer solstice is between June 21 and 22. On this day, the sun appears to be directly over the Tropic of Cancer and is completely perpendicular to the Earth's surface. On the other hand, at the Tropic of Capricorn, the sun's rays are usually perpendicular to the Earth's surface during the winter solstice, around December 23rd.
Two other important parallels are the Arctic Circle and the Antarctic Circle. These are the ones that mark the northern and southernmost points of Ecuador where the sun does not get to set on the horizon or directly does not get to rise. This is where we have complete days without nights, or complete nights without days. From these circles toward the respective poles, the number of days without light increases, then decreases until the poles experience six months of darkness followed by six months of light. The polar circles are the same distance from the poles as the tropics are from the equator.
Meridians on a coordinate map
Other important aspects of a coordinate map are the meridians. Meridians are the semicircles that extend from the poles and are perpendicular to the equator. Let's not forget that all these elements of a coordinate map are imaginary. They only serve to establish the coordinates at a point. Each meridian is composed of two semicircles, one containing the meridian in question and the other the opposite meridian. The eastern one is located east of the meridian in question, and the western one is located west of it.
The 0 degree meridian is the one that passes through the Greenwich Observatory located in London, so it is known by the name of the Greenwich meridian. This meridian is the one that divides the earth into two hemispheres: the eastern or eastern hemisphere that is located east of said meridian and the western or eastern hemisphere that is located west of it.
Latitude and longitude
These two elements are very important on the coordinate map. Any location on the Earth's surface can be referenced by the intersection of a parallel and a meridian. This is where latitude and longitude coordinates arise. Latitude provides the location of a location, whether north or south of the equator. It is expressed in angular measurements ranging from 0 degrees to 90 degrees. It is referred to as degrees north and degrees south. If we draw a straight line from a point to the center of a sphere, the angle that line forms with the equatorial plane will be the latitude of that point.
Degrees of latitude are usually evenly spaced. However, the slight flattening of the planet at the poles causes degrees of latitude to vary.
On the other hand, we have longitude. Longitude is what provides the location of a place between the east or west direction from the reference meridian known as the Greenwich meridian. and is expressed from the values of 0 degrees to 180 degrees, referring to whether it is east or west. While the degree of latitude corresponds to a distance that is almost identical, the same does not occur with the degree of longitude. This is because the circles on which we measure this distance converge towards the poles. At the Equator, there is a degree of longitude that is equivalent to a distance of 11132 kilometers and It is the result of dividing the circumference of the Equator by the 360 degrees that the circumference of the earth has.
I hope that with this information you can learn more about how a coordinate map is interpreted.
