What is a parallel on a map. Summary of the lesson "Degree network on the globe and maps

LATITUDE AND MERIDIANS

Almost everyone is familiar with mysterious lines"on maps and globes representing latitude (parallels) and longitude (meridians). They form a grid system of coordinates by which any place on Earth can be accurately determined - and there is nothing mysterious or difficult about it. Latitude and longitude are coordinates , defining the position of points on the surface of the Earth.

Two places on Earth are determined by its rotation around its own axis - these are the North and South Poles. On globes, the pivot is the axis. The North Pole is in the middle of the North Arctic Ocean, which is covered with sea ice, and researchers in the old days reached this pole on a sled with dogs (it is officially believed that the North Pole was discovered in 1909 by the American Robert Perry).

However, since the ice moves slowly, the North Pole is not an actual, but a mathematical entity. The South Pole, on the other side of the planet, has a permanent physical location on the continent of Antarctica, which was also discovered by land explorers (Norwegian expedition led by Roald Amundsen in 1911). Today, both poles can be easily reached by plane.

Halfway between the poles at the "waist" of the Earth is a large circle, which is represented on the globe as a seam: the junction of the northern and southern hemispheres; This circle is called the equator. It is a circle of latitude with zero value (0°).

Parallel to the equator above and below it are other circles - these are other latitudes of the Earth. Each latitude has a numerical value, and the scale of these values ​​is not measured in kilometers, but in degrees north and south of the equator to the poles. The poles have meanings: North +90°, and South -90°.

Latitudes located above the equator are called north latitude, and below the equator - south latitude. The lines of latitude are sometimes called parallels because they run parallel to the Equator. If parallels are measured in kilometers, then the lengths of different parallels will be different - they increase when approaching the equator and decrease towards the poles.

All points of the same parallel have the same latitude, but different longitudes (the description of longitude is just below). The distance between two parallels that differ by 1° is 111.11 km. On the globe, as well as on many maps, the distance (interval) from a latitude to another latitude is usually 15° (that's about 1,666 km). In figure No. 1, the interval is 10 ° (this is approximately 1,111 km). The equator is the longest parallel, its length is 40,075.7 km.

However, in order to accurately determine any place on the globe, it is not enough to know its position relative to north and south, you also need to know the value relative to west and east. This is what longitude lines are for. Since there is no west or east pole, it was decided that the line of zero longitude passes through the Greenwich Laboratory, located in England on the eastern outskirts of London.

Lines of longitude are called meridians (Figure 2). All of them lie perpendicular to the equator and intersect with each other at two points on the North and south poles. To the east of the zero meridian is the region of eastern longitudes, to the west - western. East longitudes are considered to be positive, west longitudes - negative.

The meridian passing through Greenwich is called the zero meridian (or sometimes the Greenwich meridian). Longitude is measured in degrees. The meeting of the east and west lines of longitude occurs at pacific ocean on the date line. All lines of longitude intersect at the poles, and there is no longitude at these places. One degree of longitude does not mean some fixed distance: at the equator, a difference in longitude of 1 degree is equal to 111.11 km, and closer to the poles it tends to zero.

The lengths of all meridians from pole to pole are equal - 20,003.93 km. All points of the same meridian have the same longitude but different latitude. On the globe, as well as on many maps, the distance (interval) from a longitude to another longitude is usually 15°.

Meridians and parallels

Meridians and parallels

Meridians and parallels
coordinate lines on a map or globe. Meridians are lines of constant longitude that pass through both poles of the planet and indicate the direction "north - south", and parallels are lines of constant latitude that run parallel to the equator in the direction "west - east". Intersecting, these lines form a grid of geographical coordinates on the map. Usually, integer meridians and parallels are drawn, but for accurate drawing and removal of coordinates, the grid can be thickened to minutes (and on large-scale maps, even to seconds). To do this, the cards have a minute frame, where fractions of degrees are marked. Depending on the method of definition, astronomical, geodesic, geographic and geomagnetic meridians and parallels are distinguished, and on the celestial sphere, respectively, celestial meridians and parallels.

Geography. Modern illustrated encyclopedia. - M.: Rosman. Under the editorship of prof. A. P. Gorkina. 2006 .

See what "meridians and parallels" are in other dictionaries:

Geographic Encyclopedia

Small circles of the sphere, composed by its intersection with a plane parallel to some basic plane (horizon, equator, ecliptic); otherwise a circle, all points of which have equal latitude, declination, or altitude. Daily P. stars small circles, ... ... Encyclopedic Dictionary F.A. Brockhaus and I.A. Efron

- (historical) The initial concept of K. can be found even among savages, especially those living along the banks and about you and having a more or less clear idea of ​​\u200b\u200bthe areas surrounding their territory. Travelers who questioned the Eskimos of S. America and ... Encyclopedic Dictionary F.A. Brockhaus and I.A. Efron

Mappings of the entire surface of the earth's ellipsoid (See Earth's ellipsoid) or any part of it onto a plane, obtained mainly for the purpose of constructing a map. Scale. K. items are built on a certain scale. Reducing mentally ... ... Great Soviet Encyclopedia

An example of a map projection Mercator projection A map projection is a mathematically defined way of displaying the surface of an ellipsoid on a plane. The essence of projections is connected with the fact that the figure of the Earth ... Wikipedia

An example of a map projection Mercator projection A map projection is a mathematically defined way of displaying the surface of an ellipsoid on a plane. The essence of the projections is related to the fact that the figure of the Earth is an ellipsoid that is not deployable in ... ... Wikipedia

Mapping of the entire surface of the earth's ellipsoid or any part of it onto a plane, obtained mainly for the purpose of building a map. K. p. draw on a certain scale. Mentally reducing the earth's ellipsoid to Mraz, one gets its geometric. model ... ... Mathematical Encyclopedia

Meridian(s) meridians and parallels coordinate lines on a map or globe. Meridians are lines of constant longitude that pass through both poles of the planet and indicate the direction "north - south", and parallels are lines of constant latitude that go ... ... Geographic Encyclopedia

Meridians and parallels are coordinate lines on a map or globe. Meridians are lines of constant longitude that pass through both poles of the planet and indicate the direction "north - south", and parallels are lines of constant latitude that run parallel ... ... Geographic Encyclopedia

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Questions before paragraph

1. What lines does the degree network of the globe consist of?

From meridians and parallels.

2. What shape and what directions do the parallels and meridians have on the globe?

All meridians pass through the geographic North and South Poles. On the globe, meridian lines are semicircles of the same length. Parallels are drawn perpendicular to the meridians - circles, all points of which are equidistant from the geographic pole. The lengths of the parallels decrease as they move away from the equator towards the poles.

3. Through what two points on the surface of the Earth do all meridians pass?

All meridians on the surface of the earth pass through the points of the north and south poles.

Questions and tasks

1. In which hemispheres is Russia located?

Russia is located entirely in the Northern Hemisphere, most of the territory of Russia is located in the Eastern Hemisphere, however East End Chukotka autonomous region located in the Western Hemisphere.

2. Determine the geographic coordinates on the globe the highest peak world - Mount Everest (Chomolungma).

Everest is considered the highest (largest) peak in the whole world, the mountain is located on the territory of China and Nepal, its geographic data is 27 ° 59' 16 "(27 ° 59' 27) northern latitude, 86 ° 55' 31" (86 ° 55' 51 ) East longitude. The height of this relief is 8848.43 meters (above the sea). Has a cold climate strong winds 200 km per hour and low temperature-60°C.

3. What parallel, multiple of 10, crosses three continents: Africa, Eurasia and South America?

The tenth parallel of northern latitude passes through the African continent through eleven countries - Guinea, Ivory Coast, Ghana, Togo, Benin, Nigeria, Cameroon, Chad, Sudan, Ethiopia and Somalia.

Eurasia is in contact with the tenth parallel by the three countries of India, Thailand, and Vietnam.

The territory of Colombia and Venezuela meet this parallel in South America.

4. What meridians, multiples of 10, cross two continents: North and South America?

These two continents are crossed by 60, 70 and 80 meridians of western longitude.

The 60 meridian passes through countries such as Canada, Venezuela, Guyana, Brazil, Bolivia, Paraguay and Argentina.

70 longitude runs through the territory North America through Canada and the USA and further through South America through Venezuela, Colombia, Brazil, Peru, Chile and Argentina.

80 meridian - through four countries - Canada, USA, Ecuador and Peru.

5. From what point on the Earth's surface can you start moving only in a southerly direction?

The North Pole is located at the highest point of the earth's axis, where all the meridians converge and the parallels narrow to total absence radius. There is no rotation that defines the western and eastern sides of the horizon. There is also no northern direction, because there is nowhere further. The road remains only to the south, no matter in which direction the traveler, who has climbed to the very top of the planet, heads.

6. How do they indicate the geographical latitude of points. Through how many degrees are the parallels drawn?

The geographic latitude of a point on the Earth's surface is the value of the meridian segment between a given point and the equator, expressed in degrees. Geographic latitudes are reported from the equator, all points lying on the equator have the same geographical latitude - 0gr. sh. All points lying in the Northern Hemisphere have a north latitude (NL) from 0 to 90 degrees, and points lying in the Southern Hemisphere have a South latitude (S) from 0 to 90 degrees. Usually, parallels are drawn on the globe, multiples of 10, 15 or 20 degrees.

7. How do they indicate the geographical longitude of points. Through how many degrees are the meridians drawn?

The longitude of geographical points is indicated on the map using meridian lines, or simply meridians. All points located east of the Greenwich (initial) meridian have east longitude (E) from 0 to 180 degrees, and points located west of Greenwich have west longitude (W) from 0 to 180 degrees. Usually on the globe, meridians, like parallels, are drawn through 10, 15 or 20 degrees.

We remember: What is called the equator? What is the length of the earth's equator? What points on Earth are called geographic poles?

Keywords:equator, parallels, meridians, prime meridian, hemisphere, degree grid, geographic location.

1. Parallels. Have you already remembered that e c v a t o r- this is a line conventionally drawn on the earth's surface at the same distance from the poles. He divides Earth to the Northern and Southern Hemispheres (Fig. 42).

Rice. 42. Hemispheres of the Earth. What separates the Western and Eastern, Northern and Southern hemispheres?

Parallels are lines that are conventionally drawn on the surface of the Earth parallel to the equator. The word "parallel" indicates the position of this line relative to the equator: all points of one parallel are at the same distance from the equator. As you can see on the globe in the shape of a parallel - a circle, their length decreases from the equator to the poles. The largest parallel is the equator. A parallel can be drawn through any point earth's surface. Each parallel is directed from west to east (Fig. 43).

Rice. 43. Parallels. Rice. 44. Meridians.

Meridians. The shortest lines, conditionally drawn on the surface of the Earth from one pole to another, are called meridians (Fig. 44). The direction of the meridian at any point on the earth's surface is most simply determined through the direction of the shadow from objects at noon. Therefore, the meridian is also called the noon line (Fig. 46). Translated from Latin into Russian, the word "meridian" means "midday line".

Figure 46. The meridian line coincides with the direction of the shadow from objects at noon.

Meridians indicate the exact direction from north to south. At each point, the meridian is perpendicular to the parallels, which is why they form a right angle (90 °) with each other. Therefore, if you become facing north, that is, in the direction of the meridian, and spread your arms to the sides, they will indicate the direction of the parallel.

Like a parallel, a meridian can be drawn through any point on the earth's surface.

One of the meridians is conditionally considered to be the initial, or zero. According to the international agreement of 1884, the Greenwich meridian passing through the Greenwich Observatory in London is considered the initial one. The initial meridian divides the globe into two hemispheres - Western and Eastern (Fig. 42).

3. Degree grid. On a globe and maps, meridians and parallels are drawn through the same number of degrees. For example, after 10 0 or 15 0 . (Find these symbols on the globe and map). Intersecting, parallels and meridians form a degree grid on the globe and maps (Fig. 45).

Rice. 45. Degree grid.

* On a globe, parallels and meridians intersect at right angles. When these angles on the map are greater or less than a straight line, this indicates distortion of angles and directions, and hence the shape of objects. On the globe, all meridians have the same length, and the length of the parallels decreases from the equator to the poles, which is true. Violation of this on the map indicates a distortion of distances, and, consequently, areas.

1. What is called a parallel? Meridian? Degree grid? 2. What hemispheres does the equator and the prime meridian divide the globe into? What hemisphere is your area in?

3* Copy table 2 in a notebook and fill it out (instead of a question, write down the answer).

Table 2.

Graticule

Practical work.

1. Find any meridian on a globe or on a map of the hemispheres and determine which continents and oceans it crosses from south to north. 2. Show any parallel and determine which continents and oceans it crosses from west to east.