Which of the following items is used to locate places in a world map? When describing location, it is common to mention the city, state, or country as a location descriptor.
It is also common to talk about landmarks that may be nearby. Another way to describe location is to use reference lines to describe coordinates, or absolute position, on the globe.
Two types of imaginary reference lines are used to locate positions or points and to make accurate globes and maps. These lines are called parallels of latitude and meridians of longitude.
Two of these imaginary reference lines, the equator and the prime meridian, are called primary reference lines because they are where we start the numbering system.
The earth completes one rotation around its axis every day. If the axis were a pole or a line instead of the earth, the two imaginary spots where it would enter and depart the planet are known as the north and south poles, respectively (see Fig. 1.9). The equatorial line is a fictitious fundamental reference line that is imagined to be traced around the planet midway between the poles. The hemisphere of the world that is located to the north of the equator is known as the northern hemisphere, while the hemisphere of the earth that is located to the south of the equator is known as the southern hemisphere (Fig. 1.9). (The word “half” is derived from the prefix hemi-, thus hemisphere literally means “half-sphere.”) The north and south orientations are determined by the poles. The direction that is taken while traveling northward is called the northerly direction. The direction that one travels in while heading toward the South Pole is southerly.
Latitude is expressed as a number of degrees (°), which range from 0 degrees to 90 degrees north or south of the equator. A fictitious point located at the earth’s center is used as the starting point for measuring latitude in degrees. This fictitious point would be the point at which a line drawn from the North Pole to the South Pole and a line drawn from the equator on one side of the earth to the equator on the other side of the globe would cross each other in the event that the planet were to be sliced in half (Fig. 1.10 A). A line that is drawn from the circumference of a circle to the center of the circle is called a radius. The angle formed by the radius lines drawn from the equator and from the north pole (or south pole), respectively, is a right angle, which has a degree measurement of 90 degrees.
The equator is located at an angle of 0 degrees, while the poles of the planet are located at an angle of 90 degrees from the equator. The angle that separates a place on the surface of the globe from the equator is what is used to calculate latitude. In order to determine the angle, you must first draw a line from the point to the center of the earth, as well as a line from the equator to the center of the earth (Fig. 1.10 A).
The parallels of latitude are fictitious reference lines that, when joined together, create complete circles around the world. These lines run in a direction that is parallel to the equator and to each other. Because every point along a latitude parallel is located at the same distance from the equator, the angle that is generated between the equator and the latitude line remains the same. This is seen in Fig. 1.10 B for the latitude lines that are 30 degrees and 60 degrees north.
The parallels of latitude are represented by circles of varying diameters (see Fig. 1.11). The parallel that runs across the equator is the longest and widest, and the parallels become shorter as you get closer to the poles. The number of degrees that a parallel of latitude is placed north (N) or south (S) of the equator is used to define it, with the exception of sites that are positioned directly on the equator (0°). The higher the latitude, either north or south of the equator, the farther away from the equator the location is. For instance, the city of Honolulu in Hawaii is located on the 21° N parallel. The city of Sydney, in Australia, is located on the 34th south parallel.
Longitude’s meridians are fictitious half-circles that stretch from the North Pole to the South Pole. Lines of longitude is another name for them in various contexts. Every line of longitude has exactly the same length, in contrast to the latitude parallels, which come in a variety of dimensions. As a result of the fact that all meridians must pass through the equator and that the equator itself is a circle, the equatorial circle may be broken up into 360 degree increments. The meridians are named after the divisions of the equatorial circle that are used to locate them.
Greenwich, England, serves as the location of the zero meridian, which is often referred to as the prime meridian, as a result of an international agreement. The prime meridian is the starting point for the numbering of all other meridians (Fig. 1.12 A).
The distance east or west of the prime meridian is referred to as longitude, and longitude is measured in degrees, ranging from 0 to 180 degrees (Fig. 1.12 B). Longitude to the east corresponds to locations relative to the prime meridian. For instance, Rome, Italy is situated on the 12 degrees East meridian, but Washington, District of Columbia, in the United States of America, is situated on the 77 degrees West meridian.
At the 180-degree meridian, which passes across the middle of the Pacific Ocean basin, the longitudes of the east and west meet (Fig. 1.13). As a result, the majority of the United States, including the state of Hawaii, is located in the western hemisphere. Only a tiny fraction of Alaska (including some of the Aleutian Islands) is east of the 180-degree meridian and so belongs to the eastern hemisphere. The prime meridian (0 degrees) and the 180-degree meridian both make a full circle around the world, and this circle serves to split the earth into its eastern and western hemispheres (see Figs. 1.12 and 1.13).
The international date line is a line that runs largely along the 180-degree meridian and is considered to be an imaginary line (see Fig. 1.14). The international date line is the geographic marker that indicates where on earth a new date begins. For instance, the time in Bangladesh is six o’clock in the morning on July 1st, while in Mexico it is six o’clock in the evening on June 30th, and in England it is midnight on June 30th. All of these times are local (see Fig. 1.15 A).
The time difference between locations that are immediately to the right and left of the date line is 24 hours. This indicates that when it is 12:00 in Tonga on Monday, July 1st, it will be noon in Samoa on Sunday, June 30th. This is because Tonga is located on the left side of the international date line, whereas Samoa is located on the right side of the date line (see Fig. 1.15 B).
Passengers who cross the dateline traveling west will experience a one-day time change, while passengers who cross the dateline heading east will experience a one-day time change. If you are heading east and crossing the dateline, there is a small chance that you may arrive at your destination sooner than when you set out.
The international date line has been shifted in order to accommodate various geographical regions’ need to stay co-located inside the same day and time zone. This was done for pragmatic reasons. As an example, the most eastern point of Russia, which protrudes into the Bering Strait, was included in the easternmost time zone, while the Aleutian Islands, which are held by the United States, were included in the westernmost time zone (see Fig. 1.15 B).
It is possible to zero in on a specific spot on a map or globe if the latitude and longitude coordinates of that location are known. When individuals go trekking, diving, or doing environmental surveys, it is helpful for them to know the spherical coordinates of the place they are in. When driving or flying, sophisticated navigational aids employ latitude and longitude to offer instructions to the driver or passenger. For ships at sea that are unable to pinpoint their locations using landmarks or coastal navigation aids like buoys or channel markers, the spherical coordinate system is an absolute need.
Marine and aerial navigators utilize the nautical mile as their standard measure of length or distance, in addition to employing latitude and longitude as the primary means by which they pinpoint a place. A distance of 1.85 kilometres, or about one minute of latitude along a line of longitude, is referred to as one nautical mile. In the world of navigation, the speed of ships and aircraft is measured in knots. Meteorologists also use the unit of knots to indicate the speed of the wind. The speed of one nautical mile per hour is equivalent to one knot.
A place’s exact position on the globe may be determined using its latitude and longitude coordinates. By identifying the points at where lines of latitude and longitude intersect, we are able to find specific locations on the globe. For example, New Orleans, Louisiana is located around 30 degrees north of the Equator and 90 degrees west of the Prime Meridian (longitude).
On Earth, there are two places that serve as points of reference: the North Pole and the South Pole. The Equator was able to be drawn with the assistance of these two locations because it is located precisely in the middle of the distance between the two poles. On the surface of the globe, a network of lines has been constructed in order to precisely pinpoint locations.
If you know the precise location, you may use that information to figure out the longitude and latitude on the map. Therefore, it is necessary for us to find places on earth in order to determine where we are, where we should go, the distance between two locations, and so on.