Define parallels and meridians in geography. Summary of the lesson "Degree network on the globe and maps

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 system of coordinates by which any place on Earth can be precisely defined - 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 coordinates of latitude and longitude. This can be most clearly studied with the help of a globe, where these lines are indicated.
But first, everything is in order. Two places on the Earth are determined by its rotation around its own axis - these are North and South Poles. On globes, the pivot is the axis. The North Pole is located in the Arctic Ocean, which is covered sea ​​ice, and researchers 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 Perry). However, since the ice moves slowly, the North Pole is not an actual, but rather 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).

Halfway between the poles at the "waist" of the Earth is a large circle line, 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 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 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 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 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.

The points of intersection of the earth's axis with the surface of the globe are called poles (North and South). The Earth rotates once around this axis in 24 hours.

A circle is drawn at the same distance from the poles, which is called the equator.

Parallel - lines conventionally drawn on the surface of the Earth parallel to the equator. The parallels on the map and the globe are directed to the west and east. They are not equal in length. The longest parallel is the equator. The equator is an imaginary line on the earth's surface, obtained by mentally dissecting an ellipsoid into two equal parts (Northern and Southern hemispheres). With such a dissection, all points of the equator are equidistant from the poles. The plane of the equator is perpendicular to the Earth's axis of rotation and passes through its center. In total, there are 180 meridians on Earth, 90 of them are north of the equator, 90 are south.

The parallels of 23.5° north and south are called tropical circles or simply tropics. On each of them, once a year, the midday Sun is at its zenith, that is, the sun's rays fall vertically.

The parallels of 66.5° northern and southern latitudes are called polar circles.

Circles are drawn through the North and South Poles, meridians are the shortest lines conventionally drawn on the surface of the Earth from one pole to another.

The prime or prime meridian was drawn from the Greenwich Observatory (London, UK). All meridians have the same length and the shape of semicircles. In total, there are 360 ​​meridians on Earth, 180 to the west of zero, 180 to the east. Meridians on the map and globe are directed from north to south.

For exact definition the location of any object on the surface of the earth, one line of the equator is not enough. Therefore, the hemispheres are mentally separated by many more planes parallel to the plane of the equator - these are parallels. All of them, like the plane of the equator, are perpendicular to the axis of rotation of the planet. You can draw as many parallels as you like, but they are usually drawn at intervals of 10-20 °. Parallels are always oriented from west to east. The circumference of the parallels decreases from the equator to the poles. At the equator, it is the largest, and at the poles it is zero:

Length of arcs of parallels

Parallels	Length 1° in km

When the globe is crossed by imaginary planes passing through the axis of the Earth perpendicular to the plane of the equator, large circles are formed - meridians. Translated into Russian, the word "meridian" means "midday line". Indeed, their direction coincides with the direction of the shadow from objects at noon. If you go all the time in the direction of this shadow, you will definitely come to the North Pole. Meridians are the shortest line conventionally drawn from one pole to another. All meridians are semicircles. They can be drawn through any point on the surface of the Earth. They all intersect at the poles. The meridians are oriented from north to south. Average length 1° arc of the meridian is calculated as follows:

40,008.5 km: 360° = 111 km

All meridians are the same length. The direction of the local meridian at any point can be determined at noon by the shadow of any object. In the Northern Hemisphere, the end of the shadow always shows the direction to the north, in the Southern - to the south.

The image of meridian lines and parallels on the globe and geographical maps is called a degree grid.

Geographic latitude is the distance of any point on the earth's surface north or south of the equator, expressed in degrees. Latitude is north (if the point is located north of the equator) and south (if south of it).

Geographic longitude is the distance of any point on the earth's surface from the prime meridian, expressed in degrees. To the east of the zero meridian will be eastern longitude (abbreviated: east longitude), to the west - western (west longitude).

Geographic coordinates - geographic latitude and geographic longitude of a given object.



Today, our associations associated with travel have changed a lot. "Unlucky Notes", "Eagle and Tails" against the backdrop of the cheapness of All Inclusive compared to the Soviet ones did their job. Does anyone now remember about "parallels, meridians"? Well, at least a song, right?

Okay, let's remember. Only cities and countries will not flicker - surprisingly, but the parallels with the meridians and next to us pass :)

Have you guessed what we're talking about yet? ;)
Then let's start from afar.
As a child, I had a globe on my desk. How to read Jules Verne without a globe?!
And now the hand does not rise to buy this invention - more a luxury item. And, as it were, irrelevant in the age of Google maps and Yandex satellite.

But I'm not talking about the globe. The journey in search of Captain Grant made the imaginary lines on the globe real, almost tangible. Man's addiction to imaginary lines is quite understandable, because they symbolize the elusive mystery of Being. Yet again pirate maps, treasures and adventures. All thirty-three pleasures. Just the silhouette of a steering wheel or the ringing of a ship's bell already triggers the imagination and makes our hearts beat! This is not a booking with a choice between BB, HB and AI.

But the Caribbean is too far away, the pirates are too old, and all this, connected together by the movie business, turns into a fantasy, killing the very real romance of distant wanderings. And if you are asked what parallel Cheboksary stands on, some will be surprised: "Well, do we have parallels?"
And when they find out that the 56th parallel runs a little to the south, they will say in disappointment: "Ah, well, I thought so, where can we ...".

Well, here it is, the 56th parallel, here, look. Exactly 56 ° north latitude (we are used to integer values, but nature doesn’t care about them, just like city planners!):

Panorama from DCP 56°N 47°E (click to view full size)

There are people for whom the awl still works, and even too much - and they invent "home" parallels with the meridians (known to some as the Hartman grid), which pass every two meters, and even teach how to properly position the bed in order to don't hit the nodes. It takes a psychic to find these lines and knots. But it's not scary, even I can do it, and even without a frame :). And everyone can, if they try.

Only here is the incident: it is customary to take the distance between the lines the same everywhere. I have never heard that the grid of Hartman and Murmansk differed from the grid, for example, in Odessa! ;) Apparently, psychics, even graduates, do not always remember the features of the geometry of the sphere. Meanwhile, you can stretch a square grid of figs onto a globe!
But let's leave the glitches of psychics aside and return to geography.
With the equator and with all the meridians it is easier: one degree when moving along them is the same everywhere and is approximately 40000/360=111 km. And one minute of arc, respectively, is 60 times less: 1.852 km.
By the way, who knows what this number is? My friends, this is a nautical mile! Have you heard of such a unit of distance?

So, with latitude, everything is clear. To get one degree north or south, you have to walk 111 km.
And how many from one meridian to another? At the equator - the same 111 km. And at the pole, obviously, zero! Because there all the meridians converge. And you can commit trip around the world" around the pole, while crossing all time zones in a few steps!
At our latitude from one meridian to another - only 62 kilometers with a tail.
Therefore, the mysterious points of intersection of parallels and meridians are not so far from us.
And these nodes are beautifully called: confluent points.
Immediately there is a desire to find them and visit. Why, ask? Well, you're not original. Vysotsky has already managed to ask you:

I asked you: "Why are you going uphill? -
And you went to the top, and you rushed into battle. -
After all, Elbrus can be seen great from an airplane ... "
You laughed and took it with you.

We went too. Will strange people ready to travel along virtual lines and their intersections, and the international Degree Confluence Project was born:

Briefly, I already wrote about those points that are located on the territory of Chuvashia (there are only three of them), c.
I visited one of them as soon as I bought a communicator with GPS. This closest point to us with coordinates 57°N 47°E is located near the village of Ishley, on the other side of the village of Khachiki. You can drive close to the point by car both through Ishley and through Khachiki:

A panorama from the point is given above, and a visit to the point is described on the DCP website.

We see that there are still many white spots on the territory of Russia (points not visited by DCP users). This does not mean that no one has ever been there, it just means that no one, even if they knew the coordinates, bothered to tell about it on the DCP project :)
Surprisingly, the lion's share of points in the European part of Russia was "discovered" by the same traveler - Vladimir Chernorutsky. Today he has 131 visited points in 5 countries!

And I must say that the points can be in the most remote and inaccessible places - taiga, swamps, and even in the middle of a lake or river. In the latter case, enthusiasts specially take with them inflatable boat and get to the right place already on the water! The nearest water point is on the Volga near Zvenigovo:

While searching for my first confluence point, I did not know anything about the Degree Confluence Project, and I safely forgot the note I read about it on Habré. But after visiting I remembered, and easily found the appropriate site. It turned out that at this point I was only the third visitor.
But, to my great surprise, on the map of Russia I found a hitherto undiscovered point N57° E47° in the Kirov region, just 180 km from my house! Well, seven miles is not a detour, as they say.
Just like , I am extremely lucky. I managed to become the discoverer of the point, ahead of the competitor by literally three days!

It took a long time to arrive, I was almost late. I chose a relatively free day and drove along the route Cheboksary - Yoshkar-Ola - Sanchursk and another 16 km, through the village with the beautiful name Smetanino (almost like visiting Uncle Fedor with Matroskin;)). Unfortunately, the last 35 km of the road (before and after Sanchursk) turned out to be a real off-road rally, suitable only for 4x4 lovers, since only memories and asphalt pits remained from the road. This segment of the journey took almost two hours! Fortunately, now the road has been repaired there, so you can drive without fear:

I had to leave the car at the nearest point on the road and walk about two kilometers through a swampy, abandoned field to a forest visible on the horizon, where the intersection point is located:

The point itself is located in the forest, fortunately not very far:

Don't forget your mosquito gear if you want to visit this place in summer! I was never able to shoot the planned panorama; hands and face were black under a layer of mosquitoes and horseflies. And here is the point. In the picture at the beginning of the post, you see a mosquito climbing into the lens, and a communicator spattered with fresh blood. So it goes! But we got:

Such geographical travels, such discoveries. It would seem that interesting? Taiga, horseflies - romance! :)
There were no more undiscovered points nearby, except in the wilds of the Kirov region and no closer than 300-400 km.
But it is not necessary to climb into the taiga far away.
It would be possible to organize tourism in the nearest points, why not? It's time to revive the romance!

By the way, one of my colleagues from Togliatti, even before the era of GPS, carefully studied maps and found out that the middle of the Volga is located near Cheboksary!
Hey city officials! Instead of constructing pathos monuments with outstretched arms and marking the “zero mile” for tourists on Red Square, it would be better to mark the middle of the Volga. And then you tell where you are from, and you have to clarify that Cheboksary is not where pasties and Cheburashka are, but between Gorky and Kazan. But now you can proudly declare: right in the center of the Volga!

Big and small trips(cm.

>> degree network, its elements. Geographical coordinates

§ 3. Degree network, its elements. Geographical coordinates

Navigating the map and finding the exact location of geographical objects on the surface of the Earth allows degree network, or a system of lines of parallels and meridians.

Parallels(from the Greek parallelos - letters, going side by side) - these are lines conventionally drawn on the surface of the Earth parallel to the equator. Parallels on the map and globe you can spend as much as you like, but usually on training maps they are carried out with an interval of 10-20 °. Parallels are always oriented from west to east. The circumference of the parallels decreases from the equator to the poles.

Equator(from lat. aequator - equalizer) - an imaginary line on the earth's surface, obtained by mentally dissecting the globe with a plane passing through the center of the earth perpendicular to the axis of its rotation. All points on the equator are equidistant from the poles. The equator divides the globe into two hemispheres - Northern and Southern.

Meridian(from lat. meridians - midday) - the shortest line conventionally drawn on the surface of the Earth from one pole to the other.

table 2

Comparative characteristics meridians and parallels

Geographic poles(from Latin polus - axis) - mathematically calculated points of intersection of an imaginary axis of rotation of the Earth with the earth's surface. Meridians can be drawn through any point on the earth's surface, and all of them will pass through both poles of the Earth. Meridians are oriented from north to south, and all have the same length (from pole to pole) - about 20,000 km. Average length of 1° meridian: 20004 km: 180° = 111 km. The direction of the local meridian at any point can be determined at noon by the shadow of any object. In the Northern Hemisphere, the end of the shadow always shows the direction to the north, in the Southern Hemisphere - to the south.

degree, or cartographic, network is used to determine geographic coordinates points on the earth's surface - longitudes and latitudes - or mapping objects by their coordinates. All points of a given meridian have the same longitude, and all points of a parallel have the same latitude.

Geographic latitude is the arc of the meridian in degrees from the equator to given point. So, St. Petersburg is located in the Northern Hemisphere, at 60 ° north latitude (abbreviated N), the Suez Canal - at 30 ° N. To determine the geographic latitude of any point on a globe or map is to determine which parallel it is located on. Any point south of the equator will have south latitude (short for S).

Geographic longitude is the magnitude of the parallel arc in degrees from the prime meridian to the given point. The initial, or zero, meridian is chosen arbitrarily and passes through the Greenwich Observatory, located near London. To the east of this meridian, eastern longitude (east longitude) is determined, to the west - western longitude (west longitude) (Fig. 10).

The latitude and longitude of any point on the Earth make up its graphical coordinates. So, the geographical coordinates of Moscow are 56 ° N. and 38° E. d.

Maksakovskiy V.P., Petrova N.N., Physical and economic geography of the world. - M.: Iris-press, 2010. - 368 pp.: ill.

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LATITUDE AND MERIDIANS

Almost everyone is familiar with the "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 precisely defined - and there is nothing mysterious or difficult about it. Latitude and longitude are coordinates that determine 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 located in the middle of the Arctic Ocean, which is covered with sea ice, and explorers 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.

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However, in order to accurately identify 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 run perpendicular to the equator and intersect each other at two points at 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°.