Degree grid of the globe. What is the longest parallel on the map of the hemispheres? What is the name of this line? And what is the shortest parallel? Southern and Northern tropics

If our planet is “cut” through the axis of rotation and perpendicular to it by many planes, then vertical and horizontal circles will appear on the surface - meridians and parallels.


The meridians will converge at their ends at two points - at the North and South Poles. Parallels, as the name implies, are parallel to each other. Meridians are used to measure longitude, parallels - latitude.

Such a simple action at a superficial glance - the "line" of the Earth - has become greatest discovery in planetary exploration. It made it possible to use coordinates and accurately describe the location of any object. Without parallels and meridians, it is impossible to imagine any map, not a single globe. And they came up with ... in the III century BC, the Alexandrian scientist Eratosthenes.

Reference. Eratosthenes possessed encyclopedic knowledge for those times in all areas. He was in charge of the legendary Library of Alexandria, wrote the work "Geography" and became the founder of geography as a science, compiled the first map of the world and covered it with a degree grid of verticals and horizontals - he invented a coordinate system. He also introduced the names for the lines - parallel and meridian.

Meridian

A meridian in geography is called a half line of a section of the earth's surface, drawn through and any point on the surface. All imaginary meridians, of which there can be an infinite number, are connected at the poles - North and South. The length of each of them is 20,004,276 meters.

Although you can mentally draw as many meridians as you like, for the convenience of movement, mapping their number, their location was streamlined by international treaties. In 1884, at the International Meridian Conference in Washington, it was decided that the initial meridian (zero) would be the one that passes through Greenwich, a district in southeast London.

However, not everyone immediately agreed with this decision. For example, in Russia, even after 1884 until the beginning of the 20th century, the zero meridian was considered to be its own - Pulkovo: it "passes" through the Round Hall of the Pulkovo Observatory.

Prime Meridian

The zero meridian is the reference point of geographic longitude. He, respectively, has a zero longitude. This was before the creation of the world's first satellite navigation system Transit.


With its appearance, the prime meridian had to be moved a little - 5.3 ″ relative to Greenwich. This is how the International Reference Meridian appeared, which is used as a reference point for longitude by the International Earth Rotation Service.

Parallel

Parallels in geography are called lines of an imaginary section of the surface of the planet by planes that are parallel. The parallels depicted on the globe are circles parallel to the equator. They are used to measure latitude.

By analogy with the Greenwich zero meridian, there is also a zero parallel - this is the equator, one of the 5 main parallels that divides the Earth into hemispheres - southern and northern. Other main parallels are the tropics North and South, the polar circles - North and South.

Equator

The longest parallel is the equator - 40,075,696 m. The rotation speed of our planet at the equator is 465 m / s - this is much more than the speed of sound in air - 331 m / s.

Southern and Northern tropics

The Tropic of South, also called the Tropic of Capricorn, lies south of the equator and represents the latitude above which noon is at its zenith on the winter solstice.

The northern tropic, also known as the tropic of Cancer, is located north of the equator and, like the southern tropic, represents the latitude over which the midday sun is at its zenith on the summer solstice.

Arctic Circle and Antarctic Circle

The Arctic Circle is the boundary of the polar day area. To the north of it, in any place at least once a year, the sun is visible above the horizon 24 hours a day, or the same amount is not visible.

The southern polar circle is similar in everything to the northern one, only it is located in the southern hemisphere.

Graticule

The intersections of meridians and parallels form a degree grid. Meridians and parallels are spaced at intervals of 10° - 20°, smaller divisions, as in the corners, are called minutes and seconds.


With the help of a degree grid, we determine the exact location of geographical objects - their geographical coordinates, calculating longitude by meridians, and latitude by parallels.

And, well. parallel f. 1. military, obsolete. A line of trenches, throughout its entire length, equally spaced from other similar lines, successively created during the gradual attack of the fortress. BAS 1. Siege trenches parallel to the besieged place. Kurg. 1777.… … Historical Dictionary of Gallicisms of the Russian Language

- (French, from Greek parallelos parallel). 1) Comparison, comparison. 2) in military affairs, three trenches are called parallels, carried out parallel to the besieged place. 3) to draw a parallel between two persons or things means to compare them ... ... Dictionary of foreign words of the Russian language

PARALLEL, parallels, women. (from Greek parallelos parallel). 1. A line or plane, throughout its entire length equally distant from another line or plane, never intersecting with it (mat.). Draw a parallel. 2. Mentally held on ... ... Explanatory Dictionary of Ushakov

See comparison put on one parallel ... Dictionary of Russian synonyms and expressions similar in meaning. under. ed. N. Abramova, M .: Russian dictionaries, 1999. parallel, comparison, likening, line, analogy, comparison, direct Dictionary of Russians ... ... Synonym dictionary

- (inosk.) comparison (a hint of parallel lines lagging behind each other at an equal distance). To put in parallel (inosk.) to compare, to make a comparison. Wed How to put the European in parallel with the national is something strange! Well, how... ... Michelson's Big Explanatory Phraseological Dictionary (original spelling)

PARALLEL, and, wives. 1. In mathematics: a straight line that does not intersect another straight line that lies in the same plane with it. Carry out paragraph 2. trans. Comparison, as well as a phenomenon, to a swarm can be compared with another, similar (book). Carry out a p. between phenomena. ... ... Explanatory dictionary of Ozhegov

parallel- zhuikelі zhapyraktar. biol. Zhuikeleri parallel zhatkan zhapyraktar. Keibir ө s i m d i k e rd i ң zh ap y r a k t a r y n d a y zhүykeler bіrіne bіrі qatarlasa, parallel to the ornalasқan. Muny p a r a l l l l zh u y k e l i zh a p y r a k t ar dep… … Kazakh tilinin tusindirme sozdigі

parallel- A line section of the surface of the globe by a plane parallel to the equator, on which all points have the same geographical latitude. Syn.: geographical parallel ... Geography Dictionary

- (from the Greek parallelos lit. walking side by side) terrestrial (geographical), line of section of the surface of the globe by a plane parallel to the plane of the equator ... Big Encyclopedic Dictionary

Female a line parallel to (something), equally spaced from another at all points and therefore never able to meet with it; isosceles, line posten, side by side, postennaya, ordinary, orderly, summed, canvas. Features go like a canvas. Damn it with ... ... Dahl's Explanatory Dictionary

The part of the machine that serves as a guide, along the cut, a rectilinear reciprocating motion of another part is performed. In a steam locomotive, for example, the crosshead serves as a guide for the crosshead during its reciprocating motion. Crosshead direction… … Technical railway dictionary

Books

• , Pestich. Parallel between the combat strength of the modern and former sailing fleets in connection with their cost: (Report made by General Pestich on April 8, 1894) R 432/495: St. Petersburg: type. book. V.P.…
• Parallel between the combat strength of modern and former sailing fleets in relation to their cost, Pestich. Parallel between the combat strength of the modern and former sailing fleets in connection with these costs: (Report made by General Pestich on April 8, 1894) R 432/495: St. Petersburg: type. book. V.P.…

Globe is a model of the earth. It clearly shows how the oceans, continents and other geographical objects are located. On the globe, the same scale is maintained in all directions, and therefore the image is obtained more accurately than on the map.

A scale must be indicated on a globe or map. It shows the degree of reduction in the size of objects and the distances between them compared to the true sizes and distances on the ground. For example, a scale of 1:50,000,000 (one fifty-millionth) 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 of the same scale as a physical map (1: 5,000,000, 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: on a map drawn up in this way, distortions are inevitable.

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 the continents, in the structure of the river network, mountain ranges, etc. Many states (for example, Denmark, Belgium, Portugal) are depicted in such small figures that they barely have enough space for one circle - symbol capital Cities. Therefore, geographical maps are created, on which a part of the earth's surface is depicted on a larger scale than on a globe.

If you look at the globe, you can see a lot of thin lines on it. Some run from top to bottom from the North Pole to the South and are called meridians. On the globe and maps, they indicate the direction to the north and south. Other lines, perpendicular to the meridians, encircle the globe, as it were. These are parallels. On maps and the globe, they 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 conditional 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 conditional lines. They are needed in order to determine the location of geographical objects by geographical 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 geographical map?
3. What is the purpose of scale on a globe and map?
4. What are parallels and meridians for?
5. Explain geographical importance the word "orient".
6. Have you ever thought about what geographical object is located in the other hemisphere in a place diametrically opposite to where your city is located? Find it on the globe and describe according to the plan:
   1. what he really is;
   2. what is the name of;
   3. where it is located: in what climatic and time zones it is located, what geographical objects are in the neighborhood.
7. Find the intersection of the equator and prime meridian.
8. Select from the list specific traits parallels:
   1. have the shape of a circle;
   2. carried out from pole to pole;
   3. they determine the direction "west - east";
   4. all the same length.

The need to accurately determine the location on the earth's surface of one's own and surrounding objects has become especially relevant for a person with the beginning of active exploration of the planet.
Geographical coordinates- latitude and longitude - are determined by the intersection point of two imaginary lines - the parallel and the meridian. The longest parallel from which latitude begins is the equator.

origin of name

An imaginary line, which is formed by points located at the same distance from both poles, divides the planet into two hemispheres, two hemispheres. The word for the name of such a border has ancient roots. The Latin aequator, equalizer, is derived from the verb aequō, to equalize. In international practice, the "equator" entered from the German language, from Äquator.

This word also has a more general meaning. In geometry, a three-dimensional body, which has both an axis and a plane of symmetry mutually perpendicular, has its own equator, its longest parallel - the intersection of the surface of the given body with the plane of symmetry. In astronomy, the celestial equator, the magnetic equator of a planet or star are known.

Earth is a geoid

The belief that the Earth has the shape of a flat disk was questioned only by ancient Greek scientists. By the end of the 19th century, it became clear that the shape of our planet is not just an ideal ball, but a special body of revolution - the geoid, the surface of which is influenced by many factors - from gravity to "cosmic wind". Two points of the geoid are determined by its axis of rotation - these are the North and South Poles. At an equal distance from them is the longest parallel on Earth, the earth's "waist" - the equator.

But the geoid does not accurately, but only approximately describes the shape of the planet. Such it would be in the absence of mountains and depressions, if there were only a calm, undisturbed surface of the oceans. This level plays important role in navigation and geodesy - from it a report of vertical marks for various technical and engineering objects is kept.

Equator length

It is also possible to understand which parallel is the longest by the specific values ​​of the geometric measurements of the geoid. The radius of the equator, as a circle "drawn" on the surface of the Earth, is equal to the radius of the planet. Precise measurements show that this parameter varies in different parts of the planet - the polar radius is 21.3 km less than the equatorial one. Average value - 6371 km

Using the formula for the circumference of a circle - 2πR - you can calculate the length of the equator. Different geophysical standards determine the figures with a difference of about 3 m, on average - 40075 km. along the meridian - 40,007 km, which proves the special geometric qualities of the geoid.

Zero latitude

The coordinate grid that covers the globe - a visual model of the globe - is formed by 360 meridians connecting the two poles, and 180 lines parallel to the equator, distributed 90 pieces to the poles, on both sides of it. Since 1884, the meridian drawn through the English capital, located in the southeast, is considered to be the beginning of the longitude count. The longest parallel dividing the northern and southern hemispheres is the origin of latitude.

Coordinates are angular values ​​and are measured in degrees. Longitude is the angle between the plane passing through the zero - Greenwich - meridian and the one that is indicated by the line connecting the earth's poles and drawn through this point. To the east of Greenwich up to 180 ° longitude is called east and is considered positive, to the west it has negative values ​​and is called west.

Points equidistant from the poles form the equatorial plane. The radius drawn from the center of the globe through a given point on its surface forms an angle with this plane, the magnitude of which is the latitude. The longest parallel has zero latitude. To the north of the equator, this angle is considered positive - from 0 ° to 90 °, to the south - negative.

Signs and rituals

The equator is only an illusory border between the two hemispheres, but it has always stirred the human imagination. It is customary for sailors from different countries to observe special rituals when crossing zero latitude, especially for those who do it for the first time. Where the equator passes inhabited places, special signs and structures are invariably erected to make the conditional line real. A rare tourist will miss the opportunity to stand with one foot in the South, and the other in It is impossible to forget after that, as the longest parallel of the globe is called.

But the equatorial zones of the Earth have other unique characteristics that give them special value. The gravitational pull here is slightly less than at other latitudes, and the rotational momentum of the globe is greater. This allows significant savings for launching spacecraft into orbit. It is no coincidence that it is in equatorial French Guiana, on the South American coast, that the most effective launch space complex, the Kourou cosmodrome, is located.