Remember: What is called the Equator? What is the length of the earth equator? What points on earth are called geographic poles?
Keywords: Equator, parallels, meridians, initial meridian, hemisphere, degree mesh, geographical position.
1. Parallels. You have already remembered that e k in a t o p - This is a line conditionally spent on the earth's surface at the same distance from the poles. He divides the globe on the Northern and South Hemisphere (Fig. 42).
Fig. 42. Hemisphere of the Earth. What divides West and Eastern, Northern and South Hemisphere?
Parallels are lines, conditionally spent 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 in the form of parallel - circle, their length decreases from the equator to the poles. The biggest parallel is the equator. Parallel can be carried out through any point of the earth's surface. Each parallel is directed from the west to the East (Fig.43).
Fig. 43. Parallels. Fig. 44. Meridians.
Meridians. The shortest lines, conditionally spent on the surface of the Earth from one pole to another, are called meridians (Fig. 44). The direction of the meridian at any point of the earth's surface is most simply determined through the direction of the shadow of the items at noon. Therefore, the meridian is also called a midday line (Fig. 46). Translated from Latin into Russian, the word "meridian" and means "midday line".
Figure 46. The line of the meridian coincides with the direction of the shade from the items at noon.
Meridians indicate the exact direction from the north to south. At each point, the meridian is perpendicular to the parallel, which is why they form a straight angle (90 °). Therefore, if you become a face to the north, that is, in the direction of the meridian, and integrates on the sides of the hand, they will indicate the direction of the parallel.
Like a parallel, meridian can be carried out through any point of the earth's surface.
One of the meridians is conditionally assumed to be initial, or zero. According to the International Agreement of 1884, Greenwich Meridian is considered primary, passing through the Greenwich Observatory in London. The initial meridian shares the globe for two hemispheres - West and East (Fig. 42).
3. Degree grid.On the globe and maps of meridians and parallels are carried out through same number Degree. For example, after 10 0 or 15 0. (Find these symbols on the globe and the card). Crossing, parallels and meridians form a degree mesh on the globe and maps (Fig. 45).
Fig. 45. Degree grid.
* On the globe of parallels and meridians intersect at right angles. When these angles on the map are greater or less direct, it indicates distortions of corners and directions, and therefore the forms of objects. On the globe, all meridians have the same length, and the length of parallels decreases from the equator to the poles, which corresponds to reality. Violation of this on the map indicates the distortion of distances, and therefore areas.
1. What is called a parallel? Meridian? Degree grid? 2. What kind of hemisphere divides the globe equator and the initial meridian? In which hemispheres is your locality?
3 * Rewrite Table 2 in the notebook and fill it out (instead of the question, write down the answer).
Table 2.
Degree grid
|
Signs of lines of a degree grid |
Meridian |
Parallel |
|
1. In which sides of the horizon are directed? | ||
|
2. What is the length of degrees? |
Decreases from ... to |
|
|
3. What is the length of kilometers? | ||
|
4. What is the length of one degree in kilometers? |
Each parallel is different: from 111 km from the equator decreases to the side ... |
|
|
5. What form do they have on the globe? | ||
|
5. What form do heissemen on the map? |
Practical work.
1. Include on the globe or on the map of the hemispheres of any meridian and determine which continents and oceans it crosses from the south to the north. 2. Show any parallel and determine which continents and oceans it crosses from west to east.
Degree of land - The system of meridians and parallels on geographical maps and globes, which serves to refer to the geographical coordinates of the earth's surface - longitude and lard - or application to the map of objects according to their coordinates.
To create a degree network, certain reference points are required. The shag-like shape of the Earth determines the existence on the earth's surface of two fixed points - Poles. Through the poles passes an imaginary axis around which the Earth rotates.
The main elements of the degree mesh card - poles, equator, meridians and parallels.
Geographic poles - Mathematically calculated points of intersection of an imaginary axis of rotation of the earth with the earth's surface.
Equator - imaginary line on the earth's surface, obtained with the mental dissection of the ellipsoid into two equal parts (Northern and South Hemisphere).
All equator's points are equivalent to poles. The plane of the equator is perpendicular to the axis of rotation of the Earth and passes through its center. The hemisphere mentally separated by another set of planes parallel to the plane of the equator.
The lines of their intersection with the surface of the ellipsoid are called parallel .
All of them, as well as the plane of the equator, perpendicular to the axis of rotation of the planet. Parallels on the map and the globe can be carried out as much as possible, but usually they are carried out on the curriculum with an interval of 10-20 °. Parallels are always oriented from west to east. The length of the circle of parallel decreases from the equator to the poles. At the equator, it is the largest, and on the poles is zero.
When crossing the globe, imaginary planes passing through the Earth axis perpendicular to the equator plane, large circles are formed - meridians .
Meridians can also be carried out through any points of the ellipsoid. All of them intersect at the points of the poles. Meridians are oriented from north to south. The average length of the arc 1 ° Meridiana: 40 008.5 km: 360 ° \u003d 111 km. The length of all meridians is the same. The direction of the local meridian at any point can be determined at noon by shadow from any item. In the northern hemisphere, the end of the shadow always shows the direction to the north, in South - south.
Degree network It is necessary to reflect the geographical coordinates of the points of the earth's surface - latitude and longitude.
Geographical coordinates.
Geographic coordinates are a geographical latitude and longitude.
Geographic latitude- The distance along the Meridian in degrees from the equator to any point on the ground surface.
The beginning of the reference is the equator. The latitude of all points on it is equal to 0. On the poles of the latitude is 90 °. North of the Equator counts the northern latitude, south-south.
Geographic longitude- The distance along the parallels in degrees from the initial meridian to any point of the earth's surface.
All meridians are equal in length, so it was necessary to choose one of them to refer. They became Greenwich Meridian, which is close to London (where the Greenwich Observatory is located). Longitude is counting from 0 ° to 180 °. To the east of the zero meridian up to 180 °, Eastern longitude is counted, to the West - Western. Thus, using a degree network, you can define exactly geographical coordinates - The values \u200b\u200bdetermining the position of the point on the earth's surface relative to the equator and zero meridian.
Subject: Degree network on globe and maps.
Objectives lesson:
- form an idea of \u200b\u200ba degree grid on the globe andgeographic map, about the difference in image of meridians and parallels;
- form an idea of \u200b\u200bparallels and meridians, their characteristics: form and length;
- learn to show the lines of parallels and meridians on the globe;
- to summarize the materials studied during past lessons.
Equipment: globes Student, Card Hemispheres, PC, Multimedia Projector, Presentation.
During the classes:
I. Organizational moment.
II. Check your homework.
Oral survey.
What is a geographical map?
What value is the plan and card in practical activities man?
On the map what scale the territory is reduced in large quantity times: 1: 5000 or 1:10 000?
Explain their point of view, based on the definition of the concept of "scale".
Task on the card: Crossword "Globus and Geographic Card".
Vertically:
1. Model globe With the outlines of sushi and water spaces.
2. The circle, conditionally carried out along the surface of the Earth parallel to the equator.
4. Parallel, conducted on the globe at the same distances from both poles.
Horizontally:
- Points on the earth's surface through which the imaginary axis of the Earth passes.
- One three-student part of the circumference.
5. Conditionally adopted line on the surface of the globe, conducted from the pole to the pole and crossing the equator at right angles.
III. Studying a new material. Slide 1..
When we first go to someone to visit, we already know where we go, because we know the address: the street, the room at home and apartments. Guys let's look carefully on the globe Slide 2. . What do we see there?
That's right, the oceans and continents are clearly visible on the globe. And what else is depicted on it in the form of a fine cob? (lines)
These lines are not simply applied so that you can determine the exact location of the object. Today we will get a closer to these amazing lines.
You already know that the globe has a line equally removed from the poles. What is it called? (equator).
Slide 3. What two parts the Equator divides the globe? (north and South Hemisphere).
Look, from the equator to the poles through the same distances lines were carried out. How do they pass? (parallel to the equator).
Parallel call lines, conditionally spent on: surfaces of the earth parallel
equator.
Slide 4. Where on the map of the hemispheres signate the designations of parallels? (circumference) . In which units indicated notation? (in degrees ). Equator has a designation 00 .
What form do all parallels have? (form of circle). Equator is the longest parallel.
What is the length of the equator? (40 000 km ). How many degrees contains a circle? (360 0). So Length 1 0 Equator is 111.3 km.
Slide 5. Are all parallels have the same length?
Length in kilometers 10 Each parallel is indicated from the edge of the card in oval.
Look at the globe. From the northern to the southern pole also lines.Slide 6.
Meridian call the shortest line, conditionally spent on the surface from one
poles to another.
Analyzing a hemisphey map, students respond to the following questions:
What form are meridians? (semi-labor ). Where on the map of the hemispheres signate the designations of meridians? (at the equator)
What direction on the earth's surface shows Meridian?
Translated into Russian, the word "meridian" means "midday line". As you can
explain such a name "(responding to these questions, students use Fig.25 p.28).
Do all the meridians have the same length? How much will it be kilometers? (20 000 km). Length 1 0. Each meridian is 111.3 km.
But the meridians are all the same, where to keep an account?Slide 7. Scientists agreed to count for the initial meridian. The one that passes through the Greenwich Observatory not far from London, so he got the name Greenwich, or initial, or zero (has the designation 00 ). There are finite meridians, it is the designation 1800 .
In order for the globe and maps to find it easier to find the equator, zero and final meridians, they allocate them with a more fat line.
Slide 8. On globes and cards, meridians and parallels are carried out through the same number of degrees, for example after 100 or 15 0 . Meridian lines and parallels on the globe and geographic mapsseparated by degrees calldegree grid.Slide 9.10.
The degree network formed by meridians and parallels allows you to find on the map and the globe any point of the earth's surface.
IV consolidation.
Look at the hemisphey map.
What lines will replace vertical series (meridians ) Show on the map
and horizontal (parallel ) show on the map
Is the length of all meridians?
Zero Meridian divides the Earth for two hemispheres. What show them on the globe and the map.
Equator divides the Earth for two hemispheres. What show them on the globe and the map.
What allows you to find a degree network formed by meridians and parallel on the map and globe?
V. Homework.Slide 11.
§11, Tasks number 3, 4, 5, 6
The degree mesh consists of a system of lines (parallels and meridians) and their coordinates. In the realities on the earth's surface these lines are absent. They are carried out on maps and plans for mathematical calculations, determining the location of the object on the surface of the Earth.
Fig. 1. Parallels and meridians ()
The direction of the meridian coincides with the direction of the shadow at noon. Meridian- The conventional line conducted on the surface of the Earth from one pole to another. The arc and the circumference of the meridian is measured in degrees. All meridians are equal, intersect in the poles, have the direction of North-South. The length of one degree of each meridian is 111 km (the length of the circumference of the Earth is divided by the number of degrees: 40000: 360 \u003d 111 km). Knowing this magnitude, it is not difficult to determine the distance in the meridian. For example, the length of the arc in the meridian is 20 degrees. To learn this length in kilometers, you need 20 x 111 \u003d 2220 km.
Meridians are usually signed on top or bottom of the card.
The countdown of meridians begins from zero meridian (0 degrees) - Greenwich.
Fig. 2. Meridians on the map of Russia
Parallel- The conditional line spent on the surface of the Earth parallel to the equator. The direction of the parallel points to the west and east. Parallels were carried out not only in parallel to the equator, but also in parallel to other parallels, they are different in length and do not intersect.
The longest parallel (40,000 km) is the equator (0 degrees).
The length of one degree of each parallel can be seen from the map frame.
Length 1 degree parallel ():
Fig. 4. Parallels (A) and Meridians (b) ()
Parallels and meridians can be carried out through any place on the earth's surface. By parallel and meridians, it is possible to determine the main and intermediate sides of the horizon. According to the meridians, the directions "North", "South", in parallel - "East", "West". Crossing, parallels and meridians form a degree network.
Files
Not additional Materials For this occupation.
"Degree grid and its elements on a globe and map"
Prepared:
Anpadian
Tat `yana Aleksandrovna,
social Studies and Geography
MKOU "Tso number 12"
Uzlovsky District
Tula region. "
Knot
2018 year
Degree grid and its elements on a globe and map.
Sometimes people in their economic activity Or in research it is very important to determine the exact location of any geographic objects on the ground surface. This can be done using a degree grid that is on each card or globe. It consists of parallel lines and meridians. The location of any point on the globe is determined bygeographic coordinates : latitude and longitude.
Degree grid Frames meridians and parallels.Meridian - The shortest line, conditionally spent the surface of the Earth from one pole to another.Meridians - These are lines that are held on the globe through the North and South Poles. Through each point on the earth's surface, a meridian can be carried out. All meridians on the globe have the same length, it is equal to an arc of 1 ° and is almost 11 km.
Parallel - All points of one parallel are equivalent from the equator. Different lengths are different: they increase when approaching the equator and decrease to poles. All the points of the same Meridian have the same longitude, but different latitudes. All points of one parallel, on the contrary, have the same latitude, but different longitude.
Parallel - lines, conditionally spent on the surface of the Earth parallel to the equator. Parallels on the map and the globe are directed to the West and East. They are not equal to each other in length. The longest parallel is the equator.
Equator - imaginary line on the earth's surface, obtained with the mental dissection of the ellipsoid into two equal parts (Northern and South Hemisphere). With such dissection, all equator points are equivalent from poles. The plane of the equator is perpendicular to the axis of rotation of the Earth and passes through its center. A total of 180 meridians, 90 of them north of Equator, 90 - south. On the map I. you can spend as much as you like, but usually they are carried out on training cards with an interval of 10-20 °. Parallels are always oriented from west to east.
The greatest parallel -equator . This circle on the surface of the globe, all points of which depend on both poles of unequal distances.Equator - Imaginary line on the earth's surface, obtained with the mental dissection of the globe with a plane passing through the center of the Earth perpendicular to the axis of its rotation.
All points at the equator are equivalent from the poles, he divides the Earth for two hemispheres - North and South. The image of a degree mesh on the plane, that is, on the map, calledcartographic grid .
On the cards of meridians and parallels are depicted in different ways. For example, on the world map, the Meridians are straight, parallel to each other, parallels - direct, perpendicular to the meridians. On the map of the hemisphere with straight lines, only the average meridian of each hemisphere and the equator is depicted, while other meridians and parallels are curved lines.
Geographic latitude - The distance along the Meridian in degrees from the equator to any point of the globe. For the beginning of the expiration of the latitude take the equator - zero parallel. The latitudes are considered to be measured from 0 ° to 90 ° on both sides of the equator and are respectively called northern or southern.
Geographic longitude - The distance along the parallels in degrees from the initial meridian to any point of the globe. Beginning the beginning of the countdown of longitude take Greenwich Meridian - Zero, which is held near London. Longitude to the east of the initial meridian, from 0 ° to 180 °, are called oriental, west - Western; Considered by parallels.
Geographic coordinates are recorded in whole degrees and minutes indicating latitude and longitude.Points of intersection of the earth axis with the surface of the globe are calledpoles (North and South). Around this axis, the land in 24 hours makes one turn.
Geographic poles - Mathematically calculated points of intersection of an imaginary axis of rotation of the earth with the earth's surface. Meridians can be carried out through any points on the earth's surface, and they will all pass through both poles of the Earth.
Meridians are oriented from north to south, and everyone has the same length (from the pole to the pole) - about 20,000 km. Medium length 1 ° Meridiana: 20004 km: 180 ° \u003d 111 km. The direction of the local meridian at any point can be determined at noon by shadow from any item.
In the northern hemisphere, the end of the shadow always shows the direction to the north, in the southern hemisphere - south. Parallels 23,5 ° north and southern latitude are called tropical circles or justtropics . At each of them, once a year, the midday sun happens in Zenith, that is, the sun's rays are falling.
Parallels 66,5 ° Northern and southern latitude calledpolar circles . Through northern I. South Poles Conducted circumference, meridians - shortest lines, conditionally spent from one pole to another.
The initial or zero meridian was held at the Greenwich Observatory (London, United Kingdom). All meridians have the same length and shape of semi-resources. A total of 360 meridians, 180 west of zero, 180 - east.
Meridians on the map and globe are directed from north to south.The latitude and longitude of any point of the Earth make up its graphic coordinates. So, the geographical coordinates of Moscow - 56 ° S.Sh. and 38 ° c. d.