Almost all of you have paid attention to the “mysterious lines” on maps and globes representing latitude (parallels) and longitude (meridians). They form a grid coordinate system by which any place on Earth can be precisely located - and there is nothing mysterious or complicated about it. Parallels and meridians are imaginary lines on the surface of the Earth, and latitude and longitude are their coordinates that determine the position of points on the surface of the Earth. Any point on Earth is the intersection of a parallel and a meridian with latitude and longitude coordinates. This can be most clearly studied using a globe, where these lines are indicated.
But first things first. Two places on Earth are determined by its rotation around its own axis - these are North and South Poles. On globes, the axis is the rod. The North Pole is located in the North Arctic Ocean which is covered sea ​​ice, and explorers in the old days reached this pole on a sleigh with dogs (it is officially believed that the North Pole was discovered in 1909 by the American Robert Peri). However, since the ice moves slowly, the North Pole is not an actual, but rather a mathematical object. U South Pole, on the other side of the planet, there is a permanent physical location on the continent of Antarctica, which was also discovered by land explorers (the Norwegian expedition led by Roald Amundsen in 1911).

Halfway between the poles at the “waist” of the Earth there is a large line of a circle, which is represented on the globe as a seam: the junction of the northern and southern hemispheres; this circle line is called - equator. The equator is a line of latitude with a value of zero (0°). Parallel to the equator, above and below it, there are other lines of the circle - these are other latitudes of the Earth. Each latitude has a numerical value, and the scale of these values ​​is measured not in kilometers, but in degrees north and south from the equator to the poles. The poles have the following values: North +90°, and South -90°. Latitudes located above the equator are called northern latitudes, and below the equator - southern latitudes. Lines with degrees of latitude are called parallels, since they run parallel to the Equator and are parallel to each other. If parallels are measured in kilometers, then the lengths of different parallels will be different - they increase as they approach the equator and decrease towards the poles. All points of the same parallel have the same latitude, but different longitude (longitude is described 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 one latitude to another latitude is usually 15° (this is approximately 1,666 km). In Figure 1, the interval is 10° (this is approximately 1,111 km). The equator is the longest parallel, its length is 40,075.7 km.

Let's remember: What is the equator called? 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, geographical location.

1. Parallels. Have you already remembered that e k 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 globe to Northern and Southern Hemisphere(Fig. 42).

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

Parallels are lines 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 can be seen on the globe by the shape of the parallel - 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, conventionally 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 “noon 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 parallel, which is why they form a right angle (90°) with each other. Therefore, if you stand facing north, i.e. 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 conventionally considered the initial, or zero. By international agreement 1884 is considered to be the initial Greenwich meridian, passing through the Greenwich Observatory in London. The prime meridian divides the globe into two hemispheres - Western and Eastern (Fig. 42).

3. Degree grid. On the globe and maps, meridians and parallels are drawn through the same number of degrees. For example, after 10 0 or 15 0. (Locate 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 the globe, parallels and meridians intersect at right angles. When these angles on the map are larger or smaller than a straight line, this indicates distortions in angles and directions, and therefore in 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 corresponds to reality. Violation of this on the map indicates a distortion of distances, and therefore areas.

1. What is a parallel? Meridian? Degree grid? 2. What hemispheres does the equator and prime meridian divide the globe into? In which hemispheres is your area located?

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

Table 2.

Degree grid

Signs of grid lines	Meridian	Parallel
1. Which sides of the horizon are they directed towards?
2. What is the length in degrees?		Decreases from... to
3. What is the length in kilometers?
4. What is the length of one degree in kilometers?		Each parallel is different: from 111 km at the equator it decreases towards...
5. What shape do they have on the globe?
5. What shape do the hemispheres have on the map?

Practical work.

1. Find any meridian on the 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.

Working with texts and working with atlas p.22.

Students are divided into groups and answer questions.

– What are meridians?

– What do they look like and why are they called that.

– Length of meridians.

– What are parallels?

– Why are they called that, what do they look like?

– length of parallels.

Teacher: What did you guys learn about the parallels?

Student response.

Parallels are lines that are conventionally drawn along the surface of the earth parallel to the equator. Let's remember what the equator is? Shown on the map and globe. At each point the parallel is directed east and west. Parallels are circles whose length decreases from the equator to the poles. Do you remember what a pole is? The longest parallel is the equator. Its length is 40,000 km. All parallels are circles whose length decreases from the equator to the poles. On a map of the hemispheres, parallels are curved lines (arcs), and the equator is a straight line.

Meridians. Translated into Russian, the word “Meridian” means “midday line”. Its direction coincides with the direction of the shadow from objects at noon. If you walk all the time in the direction of this shadow. Then you will definitely come to the North Pole, and in reverse side- to Yuzhny.

Meridians – shortest lines, conventionally carried out on the surface of the earth from one geographic pole to another. All meridians are semicircles, converge at the poles and have the same length. On a physical map of the hemispheres, the median meridian is a straight line, and the rest are arcs.

Teacher: Parallels and meridians are drawn through a certain number of degrees.

Working with maps and atlases.

Teacher: Find the equator on a physical map and on a globe. On contour map mark the equator. It divides the globe into two hemispheres (Northern and Southern). Parallels are counted from the equator. Parallels 10, 20, ... 80 degrees of the Northern or Southern Hemisphere.

Mark a 10 degree parallel Northern Hemisphere and 20 degrees southern hemisphere.

The parallels are marked in a circle on the map of the hemispheres and on the meridian (zero) on the globe.

Teacher: By agreement between the countries, the prime meridian is considered to be the meridian passing through the Greenwich Observatory in the suburbs of London. Therefore, this meridian is also called Greenwich. On the map it is shown as a bolder line than other meridians.

Mark the prime meridian on the map. It divides the globe into two hemispheres (Western and Eastern). Meridians are marked at the equator.

We complete task 43 page 36.

Teacher: Why are parallels and meridians needed?

Students: For orientation, determine and indicate the location of various geographical objects on the surface of the Earth.

Teacher: Right. The ancient Greek scientist Eratosthenes, who lived in 276 -194. BC e., for the first time proposed drawing conventional lines - parallels and meridians - on images of the earth's surface.

Determination of directions by meridians and parallels.

Teacher: What do we know? What directions do the conditional lines show?

Students: Parallels - west, east.

Meridians – north, south.

Teacher: At each point the parallel is perpendicular to the meridian. Therefore, if you stand on the ground facing north, in the direction of the meridian, spread your arms to the sides, they will indicate the direction of the parallels, i.e. west – east.

The main and intermediate sides of the horizon are determined by meridians and parallels.

1. In which direction is Cairo from St. Petersburg?
2. In what direction is Moscow from St. Petersburg?
3. In what direction from Moscow is the Red Sea.

Using conditional lines, you can determine not only directions, but also indicate the position of parts of territories and objects. To determine, for example, the northern and southern parts of Australia, you need to place a pointer on the map along a parallel that runs approximately in the middle of the continent. To the north of the pointer there will be a northern part, and to the south there will be a southern part. How do you define the western and eastern parts of Australia.

Geographic coordinates

A degree grid, or a system of lines of parallels and meridians, allows you to navigate the map and find the exact location of geographical objects on the surface of the Earth.

Geographic coordinates- this is geographic latitude and longitude, values ​​that determine the position of a point on the earth’s surface relative to the equator and the prime meridian.

Degree network necessary for counting geographical coordinates– quantities that determine the position of a point on the earth’s surface relative to the equator and the prime meridian (latitude and longitude).

Degree network- a system of meridians and parallels on geographic maps and globes, which serves to measure the geographic coordinates of the earth’s surface - latitude and longitude

Geographic poles(north and south) - mathematically calculated points of intersection of the imaginary axis of rotation of the Earth with the earth's surface.

Equator(from Latin Aequator - equalizer) - the line of intersection of the Earth's surface with a plane passing through the center of the Earth, perpendicular to the axis of rotation. The equator divides the globe into two hemispheres (Northern and Southern) and serves as the starting point for geographical latitude. Length - 40,076 km.

Equator- an imaginary line on the earth’s surface, obtained by mentally dissecting the ellipsoid into two equal parts (Northern and Southern Hemispheres). With such a dissection, all points of the equator turn out to be equidistant from the poles. The plane of the equator is perpendicular to the Earth's axis of rotation and passes through its center.

Meridian- the shortest line conventionally drawn along the surface of the Earth from one pole to the other.

Meridian(from Lat. Meridianus - midday) - a line of section of the surface of the Earth by a plane drawn through some point on the Earth's surface and the axis of rotation of the Earth. IN modern system Greenwich is taken as the prime (zero) meridian.

Meridians - lines of section of the earth's surface by planes passing through the axis of rotation of the Earth and, accordingly, through both of its poles. All meridians are considered to be semicircles that have the same length. The length of the 1st meridian is on average 111.1 km.

Meridians can be drawn through any points on the earth's surface, and they will all intersect at the poles. The meridians are oriented from north to south. The length of all meridians is the same and is 20,000 km. The direction of the local meridian can be determined at noon by the shadow of any object. In the Northern Hemisphere, the end of the shadow always points north, in the Southern Hemisphere - south. On the globe, the meridians have the shape of semicircles, and on the map of the hemispheres, the middle meridians are straight, the rest are arcs.

The hemispheres are also mentally separated by many planes parallel to the plane of the equator. The lines of their intersection with the surface of the ellipsoid are called parallels. All of them are perpendicular to the axis of rotation of the planet. You can draw as many parallels on a map and globe as you like, but usually on educational maps they are drawn at intervals of 10-20 0 . The parallels are always oriented from west to east. The circumference of the parallels decreases from the equator to the poles from 40,000 to 0 km. The shape of the parallels on the globe is a circle, and on the map of the hemispheres the equator is a straight line, and the remaining parallels are arcs.

Parallels- these are lines conventionally drawn on the surface of the earth parallel to the equator.

Parallels- lines parallel to the equator are directed from west to east. Their length decreases from the equator to the poles.

Parallels- lines of section of the surface of the globe by planes parallel to the plane of the equator (the longest parallel).

A parallel is a circle. The length of the 1° parallel at the equator is 111 km, but decreases when moving from the equator to the poles to 0 km.

Geographic latitude - the distance along the meridian in degrees from the equator to any point on the surface of the Earth. Latitudes are measured along the meridian from the equator to the north (north latitude) and south (south latitude) from 0º to 90º.

Geographic latitude- the magnitude of the meridian arc in degrees from the equator to the parallel passing through given point. Changes from 0 (equator) to 90° (poles). There are northern and southern latitudes. All points lying on the same parallel have the same latitude.

So, Saint Petersburg located in the northern hemisphere, at 60 0 northern latitude(n. sh.), Suez Canal-at 30 0 N Determining the geographic latitude of any point on a globe or map means determining what parallel it is on. Moscow, for example, is located between 50 0 and 60 0, but closer to the 60th parallel, therefore, the latitude of Moscow is approximately 56 0 s. w. south of the equator, any point will have south latitude (S)

Geographic longitude- the distance along the parallel in degrees from the prime meridian to any point on the earth’s surface. Longitude is measured from the prime meridian to the east (east longitude) and west (west longitude) from 0º to 180º.

Geographic longitude- the magnitude of the parallel arc in degrees from the prime meridian to the meridian passing through a given point. According to international agreement, the prime meridian is the meridian passing through Greenwich Observatory in the suburbs London. To the east of it the longitude is eastern, to the west it is western. The Prime Meridian and the 180 0 degree meridian divide the Earth into the Eastern and Western Hemispheres. Longitude varies from 0 to 180°. All points lying on the same meridian have the same longitude.

The latitude and longitude of any point on Earth make up its geographical coordinates. So the geographical coordinates of Moscow are 56 0 s. w. and 38 0 in. d.

Globe is a model of the globe. It clearly shows how the oceans, continents and others are located geographical features. The globe maintains the same scale in all directions, and therefore the image is more accurate than on a map.

The scale must be indicated on a globe or map. It shows the degree to which the sizes of objects and the distances between them are reduced in comparison with the true sizes and distances on the ground. For example, a scale of 1:50,000,000 (one part of fifty million) means that the reduction is 50 million times, that is, 1 cm on a globe or map corresponds to 500 km on the ground.

But globes have a major drawback: they are always on a small scale. If we wanted to make a globe the same size as physical map(1: 5000 000, that is, 1 cm - 50 km), then its diameter would be almost 2.5 m. It is inconvenient to use such a globe.

1. Modern globe. 2. Examples of scales. 3. The surface of the globe, cut into strips along the meridians: distortions are inevitable on a map compiled in this way.

Distances on the globe are determined using a flexible ruler, strip of paper or thread.

On ordinary school globes it is impossible to depict small details in the outlines of continents, in the structure of river networks, mountain ranges, etc. Many states (for example, Denmark, Belgium, Portugal) are depicted with such small figures that there is barely enough space for one circle - symbol capitals. Therefore, they are created geographical maps, on which part of the earth's surface is depicted on a larger scale than on the globe.

If you look at the globe, you can see many thin lines on it. Some go from top to bottom from North Pole to the South and are called meridians. On the globe and maps they indicate the direction of north and south. Other lines, perpendicular to the meridians, seem to encircle the globe. These are parallels. On maps and the globe they are used to determine the direction to the west and east. The parallels are not equal in length. The longest parallel is the equator, the shortest are located near the poles.

1-2. Meridians and parallels are conventional lines on the globe and map. 3. Degree network. 4. Determination of the directions “north - south” along the meridian. 5. Determination of the directions “west - east” along the parallel.

Both parallels and meridians are conventional lines. They are needed in order to determine the location of geographic objects by geographic coordinates.

Questions and tasks

1. What is a globe?
2. How is it different from a map? Find in the text of the paragraph the answer to the question: what is the main advantage of a globe compared to a geographic map?
3. What is the purpose of indicating scale on a globe and map?
4. Why are parallels and meridians needed?
5. Explain the geographical meaning of the word "orientate".
6. Have you ever wondered what geographical object is located in another hemisphere in a place diametrically opposite to where your city is located? Find it on the globe and describe it according to plan:
   1. what he is;
   2. what is it called;
   3. where it is located: in what climatic and time zones it is located, what geographical objects are nearby.
7. Find the intersection of the equator and the prime meridian.
8. Select from the list characteristic features parallels:
   1. have the shape of a circle;
   2. carried from pole to pole;
   3. they determine the direction “west - east”;
   4. all the same length.