How many degrees are the meridians separated through? Degree grid of the globe. Elements of the degree grid
Question 1. List the planets that make up the Solar System. Which of them receive more heat than our planet? Which ones are smaller?
There are 8 planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Mercury and Venus receive more heat, Mars, Jupiter, Saturn, Uranus, and Neptune receive less heat.
Question 2. What is the influence of the Sun on the nature of the Earth?
The sun has a multifaceted impact on both living and inanimate nature of the Earth. The main influence is that the Sun is a source of heat and light.
Question 3. What is an orbit?
Orbit is the path of a celestial body in the gravitational field of another body (star, planet, comet, asteroid).
Question 4. How long does it take for the Earth to complete a revolution around the Sun?
365 days 5 hours 48 minutes 46 seconds
Question 5. What is a day? Under what conditions can the length of the Earth's day change?
A day is the period of rotation of the Earth around its axis. A period of time equal to 24 hours, the length of day and night. When the Earth's rotation speed around its axis decreases or increases, the length of the day may change.
Question 6. What are geographic coordinates? What are the smallest and largest values that geographic latitude and geographic longitude can have?
Geographic coordinates are angular values: latitude and longitude that determine the position of objects on the earth’s surface and on the map. The highest value of longitude: 180, latitude: 90 (at the pole). The smallest value of longitude: 0 - Greenwich meridian, latitude: 0 - equator.
Question 7. Are there points on Earth for which only one coordinate is sufficient to determine the geographic location?
There are two points on Earth that have a single coordinate: the North Pole is 90 degrees north latitude, and the South Pole is 90 degrees south latitude.
Question 8. Determine from the map of the hemispheres which of the objects have coordinates: a) 2° south. w. 78° W d.; b) 28° N. w. 77° east d.; c) 13° S. w. 26th century d.
Which of these objects is the northernmost, the southernmost, the westernmost and the easternmost?
a) Chimborazo (mountain in Ecuador) - the westernmost; b) Delhi (capital of India) - the northernmost and easternmost; c) In the Lusaka region (Zambia) - the southernmost.
Question 9: Since the equator is a circle, it contains 360°, which is approximately 40,000 km. Determine what the length of 1° arc of the equator is. If the distance between objects at the equator is 15°, what is this distance in kilometers?
40000/360= 111.1 km in one degree
15*111.1= 1666.5 km at 15 degrees
Question 10. How many meridians and parallels can be drawn on the globe?
You can draw as many parallels and meridians as you like on the earth's surface. However, through any one point you can only draw one parallel and one meridian (except for the poles).
It’s embarrassing to remember, but for a long time at school I couldn’t understand why it was necessary to decorate the globe with incomprehensible stripes. It’s good that the teacher had patience and explained to me what was what, and today it’s funny to remember this. In general, I will try to explain.
What are meridians and parallels
These are the names of the lines that can be found on any map, and in general they form grid coordinates. Such a system makes it possible to characterize the position of any object on the globe. Each point is the intersection of a meridian (longitude) and a parallel (latitude), which is especially evident when looking at the globe. Its core is an imaginary straight line - an axis that connects 2 opposite points, or poles. At an equal distance from them is the equator - the imaginary “belt” of the planet, which corresponds to the “0°” mark relative to latitude. Each subsequent step towards one of the poles will have its own meaning: with a “+” sign for the North, and with a “-” sign for the South.
However, knowing latitude alone is clearly not enough, so the need arose for meridians, where the “zero” is an imaginary line passing through the town of Greenwich, England. It forms hemispheres - eastern and western, and the position of the object is determined in degrees.
How many meridians and parallels can you draw?
Such an elementary action as dissecting the Earth with lines is a significant event in the history of geography. This made it possible to accurately indicate the position of any object, and today it is impossible to imagine a single globe or map without these stripes. So, now we can summarize the information:
- longitude, like latitude, is indicated by lines;
- equator - “zero” latitude, which divides the Earth into the Southern and Northern Hemispheres;
- “zero” meridian - divides it into Western and Eastern;
- opposite poles are connected by an axis - an imaginary straight line.
As for the number of lines, it is not limited by anything, but it should be remembered that only one meridian or one parallel can be drawn through any point, with the exception of the poles, where the number of meridians is not limited.
Answer from Daria[guru]
Meridian, Equator
MERIDIAN - Half the circumference of a great circle [a], the plane of which passes through the axis [c] of rotation of the earth. That is, a line that runs from the north pole to the south [red line in the figure].
The prime meridian is the meridian from which longitude is measured. The prime meridian divides the earth into two hemispheres - western and eastern.
Now the zero meridian is considered to be the one that passes through the old observatory in the English city of Greenwich. And it's called Greenwich. Any point on the prime meridian will have a longitude value of 0°
In addition to the Greenwich Prime Meridian, there are others. For example, in old maps they used -
Pulkovo meridian, shifted from Greenwich by +30°19"39""
Parisian meridian, shifted from Greenwich by +2°20"14""
Ferro meridian, shifted from Greenwich to -17°39"46""
Equator
EQUATOR - The circumference of a great circle [a], the plane of which is perpendicular to the axis of rotation of the earth [c].
The equator divides the earth into the northern and southern hemispheres. Latitude begins from the equator. The definition of the equator as the zero parallel is accepted. Any point on the equator has a latitude value of 0°.
Regardless of the prime meridian used on the map, the equator remains the same. That is, there is only one equator, but the prime meridians are different.
Parallels PARALLEL - Circles of small circles [a] parallel to the equator. In this case, the equator is the zero and longest parallel.
You can imagine parallel cables strung on an axis, which, as they move away from the equator, in one direction or another, decrease in diameter.
Meredians and parallels It turns out that in cartography the earth is divided into meridians [a] and parallels.
All meridians converge at the poles, all parallels are parallel to the equator.
Any point on the surface of the earth is the intersection of a meridian and a parallel [c].
In this case, the coordinate of a point on the surface is determined by the values of latitude and longitude.
The point at the intersection of the prime meridian and the equator (zero parallel) will have a coordinate of 0° latitude and 0° longitude.
Longitude LONGITUDE - eng. Longitude Longitude icon
The angle between the plane of the prime meridian and the plane of the meridian passing through a given point [c]. Or in other words, the angle between the direction from the center of the earth to a point on the prime meridian and the direction from the center of the earth to a point on the surface.
In this example, the longitude of this point [c] will be equal to the angle [Longitude icon], and the longitude of the point is 0°, since the longitude of any point on the prime meridian is 0°. Longitude can be expressed in angular and linear quantities, as well as in time.
Longitude is divided into western and eastern. Counted from the prime meridian, in the range from 0° to 180°. Western longitude is considered negative (from 0° to -180°), eastern longitude is considered positive (from 0° to 180°).
Latitude LATITUDE - eng. Latitude Latitude icon
The angle between the plane of the equator and the plane that passes through the center of the earth [a], and a point on the surface of the earth [c]. Or in other words, the angle between the direction from the center of the earth to the equator and the direction from the center of the earth to a point on the surface. That is, the latitude of point [c] is equal to the angle [Latitude icon], the latitude of the point is 0°, like the latitude of any other point on the equator. Each parallel is at its own latitude. Latitude is divided into northern and southern, measured from the equator to the poles 0° to 90° (Examples: Top-North, Bottom-South)
It is generally accepted that points located in the southern hemisphere are negative from 0° to -90°, and in the northern hemisphere positive from 0° to +90°.
If our planet is “cut” through the axis of rotation and perpendicular to it by many planes, then vertical and horizontal circles - meridians and parallels - will appear on the surface.
The meridians will converge at two points - at the North and South Poles. Parallels, as the name suggests, are parallel to each other. Meridians serve to measure longitude, parallels - latitude.
An action so simple at a superficial glance - “ruling out” the Earth - became the greatest discovery in the study of the planet. It made it possible to use coordinates and accurately describe the location of any object. Without parallels and meridians it is impossible to imagine a single map or a single globe. And they were invented... in the 3rd century BC by the Alexandrian scientist Eratosthenes.
Reference. Eratosthenes had encyclopedic knowledge in all areas at that time. 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 names for lines - parallel and meridian.
Meridian
In geography, a meridian is half a sectional line of the earth's surface drawn through any point on the surface. All imaginary meridians, of which there can be an infinite number, connect 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 ease of movement and mapping, their number and location have been regulated by international treaties. In 1884, at the International Meridian Conference in Washington, it was decided that the prime meridian (zero) would be the one that passes through Greenwich, a county in southeast London.
However, not everyone immediately agreed with this decision. For example, in Russia, even after 1884 until the beginning of the twentieth century, the zero meridian was considered to be its own - Pulkovsky: it “passes” through the Round Hall of the Pulkovo Observatory.
Prime Meridian
The prime meridian is the starting point of geographic longitude. He himself, accordingly, has zero longitude. This was the case before the creation of the world's first satellite navigation system, Transit. 
With its appearance, the prime meridian had to be shifted slightly - 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
In geography, parallels are lines of an imaginary section of the surface of the planet by planes that are parallel to the equatorial plane. The parallels depicted on the globe are circles parallel to the equator. They are used to measure geographic latitude.
By analogy with the Greenwich prime meridian, there is also a zero parallel - this is the equator, one of the 5 main parallels, which 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 greater than the speed of sound in air - 331 m/s.
Southern and Northern tropics
The Tropic of the South, also called the Tropic of Capricorn, lies south of the equator and is the latitude above which the midday sun 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, similar to the southern Tropic, represents the latitude above which the midday sun is at its zenith on the day of the summer solstice.
Arctic Circle and Antarctic Circle
The Arctic Circle is the boundary of the polar day region. 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 not visible for the same amount of time.
The Southern Arctic Circle is similar to the Northern Circle in every way, only it is located in the southern hemisphere.
Degree grid
The intersections of meridians and parallels form a degree grid. Meridians and parallels are spaced at intervals of 10° - 20°; smaller divisions, as in angles, are called minutes and seconds. 
Using a degree grid, we determine the exact location of geographic objects - their geographic coordinates, calculating longitude using meridians, and latitude using parallels.
2. Please note that, unlike a site plan, a geographic map is covered with a network of thin lines. The lines on the map connecting the north and south poles are called meridians. Slide 2, 3.
Translated into Russian, the word “Meridian” means “midday line”. How can you explain such a name? Slide 4.
3. Show meridian lines on a globe, a map of the hemispheres.
4. After how many degrees are drawn meridians on the globe? On the map?
5. Remember how to find the direction north from any point on a terrain plan?
6. How to determine the direction north on a map?
7. What shape do the meridians on the globe have? Slide 8.
8. What is the size of the meridians in degrees? In kilometers? Slide 16.
9. Carrying out educational practical work. Calculate the length of Africa along the 20th meridian.
Algorithm for performing the work. Slide number 17
1. Select a segment of the 20th meridian within Africa.
2. Label the degrees of the end points of the continent on this meridian -32 and 34.
3. Calculate how many degrees the meridian extends within the continent (32+34=66).
4. Determine how many kilometers it extends (111 km * 66 = 7326 km).
10. Carrying out educational practical work. Calculate the length of Africa along the 10th parallel.
Work execution algorithm (slide no.)
1. Select a segment of the 10th parallel within Africa.
2. Label the degrees of the end points of the continent at this parallel -12 and 52.
3. Calculate how many degrees the parallel extends within the continent (12+52=64).
4. Determine how many kilometers it extends (109 km * 64 = 6,976 km).
11. Consolidation. Carrying out similar practical work without the help of a teacher.
1. Select a segment of the 100th meridian within North America.
2. Label the degrees of the end points of the continent on this meridian - 68 and 17.
3. Calculate how many degrees the meridian extends within the continent (68-17=51).
4. Determine how many kilometers it extends (111 km * 51 = 5661 km).
12. Independent work on determining the extent of continents and determining directions.
Carrying out similar practical work without the help of a teacher.
1. Select a segment of the 60th meridian within South America.
2. Label the degrees of the end points of the continent on this meridian -8 and 38.
3. Calculate how many degrees the meridian extends within the continent (8+38=46).
4. Determine how many kilometers it extends (111 km * 46 = 5106 km).
13. Summarizing. Grading.
14. Homework. Paragraph 11, repeat terms and concepts.
