What is the shape of the Earth?
2 What evidence does modern science have for the sphericity of the Earth?
3 Tell us about the main quantities that characterize the size of the Earth: radii (polar and equatorial), length of the equator and meridian, surface area.
4. What is the significance of the shape and size of the Earth?
5. How would the nature of the Earth change if it were significantly smaller or large sizes at the same density of matter?
Remember! How is the globe visually depicted, what are the properties of this image? What's happened geographical map? What elements does it consist of? What difficulties arise when depicting a spherical earth's surface on a plane? How are they overcome? What inaccuracies does the image lead to? globe on a plane? How is a map different from a plan? How are maps divided by content and scale? How are the cards used?
Globe. Degree network. Geographic coordinates
Globe- a reduced volumetric model of the Earth, conveying its spherical shape. Are saved on the globe geometric properties depicted geographical objects (continents, oceans, rivers, lakes, etc.) - their linear and areal dimensions, angles and shapes. The globe gives a similar image of the earth's surface, its scale is the same in all places. School globes are usually made on a scale of 1:50,000,000, i.e. 1 cm on a globe corresponds to 500 km on the earth's surface. For distances on the globe, you need to use a thread or a strip of paper to measure the distance between given points and, knowing the scale of the globe, calculate the true distance using proportion.
To determine the position of geographical objects on the earth's surface, it is used degree network- system of meridians and parallels. During the daily rotation of the Earth, two fixed points are preserved - the poles, which serve as reference points.
Geographic poles- North and South- the point of intersection of the Earth's imaginary axis of rotation with the Earth's surface.
Equator(from Latin aequator - equalizer) - the line of intersection of the globe with a plane passing through the center of the Earth perpendicular to its axis of rotation. The equator divides the globe into two hemispheres: northern and southern. Its length is about 40,076 km.
Parallels(from the Greek parallelos - walking side by side) - lines of section of the surface of the globe by planes parallel to the equatorial plane. Otherwise, these are lines on the surface of the Earth drawn parallel to the equator. The length of the parallels decreases from the equator to the poles, so the length of the 1° arc of different parallels is not the same.
Meridians(from Latin meridianos - midday) - 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. The total length of the earth's meridian is about 40,009 km. The length of the 1st meridian is on average 111.1 km. Due to the oblateness of the Earth, it is larger (111.7 km) at the poles and smaller at the equator (110.6 km). The direction is determined at noon by the shortest shadow of vertical objects.
The lines of the degree network on the globe are arcs of circles and intersect at right angles. The cells formed at the intersection of parallels and meridians are equilateral spherical trapezoids. The area of trapezoids located at the same latitude is the same.
The degree network allows you to determine the location of any point on the earth's surface using geographic coordinates - latitude and longitude(Fig. 3).
Geographic latitude φ- the angle between the equatorial plane and the plumb line at a given point, otherwise- angular distance of a point from the equator. Changes from 0 (equator) to 90° (poles). Distinguish northern And southern latitude. All points lying on the same parallel have the same latitude. On a globe, parallels are marked on the zero and 180° meridians, on maps - on the side frames. In practice, geographic latitude is determined from celestial bodies using an instrument sextant. In addition, in the northern hemisphere you can navigate approximately by the height of the North Star above the horizon, which is located near the North Pole of the world (at an angular distance of 55").
Geographic longitude λ- dihedral angle formed by the plane of the prime meridian and the plane of the meridian passing through this point, otherwise- angular distance of a point from the prime meridian. According to international agreement, the prime meridian is the meridian passing through the Greenwich Observatory in the suburbs of London. To the east of it - longitude east, to the west - western. Longitude varies from 0 to 180°. All points lying on the same meridian have the same longitude. On a globe, meridians are signed at the equator, on maps - on the upper and lower frames. In practice, geographic longitude is determined by the difference in local time between the prime meridian and the meridian of the observation point.
Map and plan
Map(from the Greek saPez - leaf) - a reduced, generalized image of the Earth’s surface and related objects and phenomena on the plane, built according to a certain mathematical law in the system symbols. Maps display the location of natural and social phenomena on the earth's surface, their properties and relationships; they allow you to simultaneously view arbitrarily large spaces. Thanks to selection and generalization, typical features and characteristic features mapped phenomena. The mathematical basis of maps includes scale and cartographic projection, which determine the degree of reduction in the size of objects on the map, their correct geographical location, as well as the nature and magnitude of distortions that are inevitable when depicting a ball (or ellipsoid) on a plane. The scale of maps of vast territories varies in different parts cards. Using symbols, it is possible to display on maps not only objects visible on the ground, but also those that do not have geometric outlines (wind, precipitation, air temperature, etc.).
Plan- a symbolic drawing of a small area of terrain on a large scale (1:5000 and larger), built without taking into account the curvature of the earth’s surface. The scale of the plan is constant at all points.
Differences between a plan and a map:
1. The plan shows small areas earth's surface: school site, village, etc. Plans are drawn up directly on the ground. Maps depict much larger territories and on a smaller scale than the plan. In this case, a variety of materials are used depending on the content of the map, including satellite images.
2. All objects and details of the area are plotted on the plan at a given scale. The most significant objects and their properties are selected for maps depending on their content and purpose.
3. When drawing a plan, the curvature of the earth's surface is not taken into account due to its negligible value. All objects are shown as they really are, without distortion, their outlines are preserved, only the size is reduced in accordance with the scale. When constructing maps, the sphericity of the Earth must be taken into account, so distortion of objects is inevitable. Moreover, those objects whose display is necessary, but they do not appear on the scale of the map, are depicted with out-of-scale signs.
4. Plans do not have a degree grid, but maps usually have meridians and parallels.
5. On the plans, the direction to the north is shown by an arrow with
north-south designation. On maps, the direction north-south is determined by meridians, west-east - by parallels. They can ,
be not only straight lines, but also lines of different curvature depending on the projection of the maps.
This video lesson is devoted to the topic “Globe - a model of the Earth. Geographic maps". You will learn about the size and shape of the Earth, and become acquainted with a new concept - “geographic maps”. The teacher will tell you in detail about the globe, as well as what types of maps exist.
Based on the shape and size of the planet, a model of the Earth was created - a globe.
A three-dimensional reduced model of the Earth. The globe has the same shape as the planet itself, it is three-dimensional, its axis of rotation, like the planet’s, is tilted.
The globe depicts continents, islands, oceans, seas, etc. They have the same outlines as on the surface of the Earth, and are located relative to each other in the same way. Thus, on the globe there is minimal distortion of the earth's surface.
The first globe was created around 150 BC. e. The oldest globe that has survived to this day is the globe of Martin Behaim.
Rice. 3. Globe of Behaim, 1492 ()
In addition to the globe and plans, maps are actively used to depict the earth's surface. On a map, unlike a plan, you can see the entire earth's surface or large parts of it. In addition, geographic maps have a small scale, since the image has to be reduced in size large number times so that it fits on the map.
Geographic map- an image of the earth's surface containing a degree grid, in a reduced form on a plane using symbols.
Geographic maps are completely different. For example, maps that depict natural objects: mountains, seas, plains, continents are called physical; maps showing countries, their borders, capitals - political.
Rice. 4. Physical map of the world ()
Rice. 5. Political map of Eurasia ()
Eat special kind maps - contour maps. These maps have only the boundaries of geographical objects, their outlines, and a degree network. On such maps it is necessary to independently mark the geographical objects being studied, maintaining accuracy, accuracy and using other geographical maps.
Rice. 6. Outline map of the world ()
Homework
Paragraphs 9, 10, 11.
1. What are a globe and a map?
References
Main
1. Basic course in geography: Textbook. for 6th grade. general education institutions / T.P. Gerasimova, N.P. Neklyukova. - 10th ed., stereotype. - M.: Bustard, 2010. - 176 p.
2. Geography. 6th grade: atlas. - 3rd ed., stereotype. - M.: Bustard, DIK, 2011. - 32 p.
3. Geography. 6th grade: atlas. - 4th ed., stereotype. - M.: Bustard, DIK, 2013. - 32 p.
4. Geography. 6th grade: cont. cards. - M.: DIK, Bustard, 2012. - 16 p.
Encyclopedias, dictionaries, reference books and statistical collections
1. Geography. Modern illustrated encyclopedia / A.P. Gorkin. - M.: Rosman-Press, 2006. - 624 p.
Literature for preparing for the State Exam and the Unified State Exam
1. Geography: initial course. Tests. Textbook manual for 6th grade students. - M.: Humanite. ed. VLADOS center, 2011. - 144 p.
2. Tests. Geography. 6-10 grades: Educational and methodological manual / A.A. Letyagin. - M.: LLC "Agency "KRPA "Olympus": "Astrel", "AST", 2001. - 284 p.
Materials on the Internet
1. Federal Institute of Pedagogical Measurements ().
2. Russian Geographical Society ().
The globe and the map are the main symbols of geographical science, reminding us of tempting journeys to distant lands. Despite the fact that both of these objects depict the earth's surface, there are a number of fundamental differences between them.
Map– this is a generalized image of the earth’s surface, made on a plane, to scale, using conventional signs.
Comparison
The globe is the most accurate model of the Earth. It appeared in 1942 thanks to the German Martin Beheim, who worked at the Geographical Institute. The first model was missing half of the continents and islands that exist on Earth, but it was this model that became the forerunner of the Age of Discovery. The modern globe depicts all the continents and oceans on the planet. Traditionally, globes are produced in two types – general geographical and political.
Globe
The map appeared in the 3rd century BC. A certain Eratosthenes, later called the “father of geography,” depicted the parts of Europe, Asia and Africa known at that time, and also drew the rudiments of a degree grid on his map.
It is the smooth surface of the globe that emphasizes: relative heights on Earth are much inferior to its horizontal distances. The peculiarity of this item is that the degree grid, the shape of parallel meridians, the configuration of geographical objects, their linear and territorial dimensions correspond to the actual ones, that is, they are depicted without distortion. Naturally, scale is also taken into account.
Due to the fact that the globe complies with the principles of equidistance, equidistance and equiangularity, it is an indispensable device in astronautics, sea and air navigation.
Since the map represents the earth's surface depicted on a plane, all objects, their configuration, areas and distances on it are subject to distortion. Therefore, depending on the purpose of the map, a projection is selected - cylindrical, conical or azimuthal, which minimizes distortion.
Map of Russia All objects on the map are depicted using conventional signs: icons, linear, movement lines, isolines, the method of areas and layer-by-layer coloring, which facilitates mapping and improves the degree of information perception by the consumer.
Maps are divided according to the level of reduction of the earth's surface - large-, medium- and small-scale, by purpose, by content and by the area of the illuminated territory.
Maps are easier to use than globes.
Conclusions website
- The map appeared earlier, the globe eighteen centuries later.
- The globe depicts the entire Earth, and the map can show viewers both the entire planet and individual continents, countries, parts of the world, regions, cities, streets.
- Geographical objects, their areas and distances between them are transmitted on the globe without distortion, unlike the image on the map.
- A globe is less convenient to use than a map.
Slide 2
Globe
Stands on one leg
He twists and turns his head.
Shows us countries.
Rivers, mountains, oceans.
Provide evidence that the Earth is spherical.
- The shape of the Earth is clearly visible in its miniature model, which is called the terrestrial globe. Continents and islands, oceans and seas are depicted on its surface. They have the same outlines and are located in the same way as on the Earth itself, only reduced by several million times.
- A globe is a model of the Earth. A model is a reduced-scale reproduction of an object. This means that the globe also has a scale.
Slide 3
- Using the globe, determine the distance from Moscow to St. Petersburg.
- Determine the scale of the educational globe.
- Using a globe, determine the distance from Moscow to Novosibirsk
- Using a globe, determine the distance from Moscow to the equator
Slide 4
Dimensions of the Earth
The distance from the center of the Earth to the equator is 6378 km, and from the center to the poles I am 22 km and equal to 6356 km. The circumference of the Earth is 40 thousand km. It would take about a month to travel this distance by fast train. And walking takes about five years. - 22 km
- The average radius of the earth is 6371 km
- The total area of the planet is 510 million km²
Slide 5
Geographic map
It looks like a piece of paper
Our Earth is a very clever drawing.
Mountains, plains, seas, oceans,
There are cities on the map, and countries...
Slide 6
Distortions on the geographical map
Which parts of the map have the most distortion in the images?
Slide 7
Types of projections
Construction
Cylindrical (1),
Conical (2)
Azimuthal (3)projections
Which continent on the map of the hemispheres has the greatest distortions?
Slide 8
Similarities and differences between a plan and a map
Compare the terrain plan and the physical map of the hemispheres in the atlas.
Identify similarities and differences on the site plan and on the map.
- Conventional signs
- Conventional signs
- Scale
- Scale
- Off-scale signs
What information can you get about rivers from a plan and a map?
Geographic map is a reduced image of the Earth's surface or its parts on a plane using symbols.
Slide 9
Types of cards
- Describe the atlas maps
- Physical map of the hemispheres
- Physical map of Russia
- Political map of the world
- Oceans map
- Outline maps
- Atlas page
- Atlas page
- Atlas page
- Atlas page
- Atlas page
We will answer the following questions.
1. How are geographical maps different from a globe?
A globe is a three-dimensional model of the Earth. A map is a generalized image of the earth's surface, made on a plane, to scale, using conventional symbols.
The undeniable advantages of the globe include the following:
A globe is more visual compared to a map. It shows the spherical shape of the Earth.
Saved relative position relative to each other's poles, as well as meridians and parallels.
The scale is the same in all parts of the globe.
The shapes of objects and their proportions are not distorted.
The map can show viewers both the entire planet and individual continents, countries, parts of the world, regions, cities, and streets. Geographical objects, their areas and distances between them are transmitted on the globe without distortion, unlike the image on the map.
2. Why are geographical maps more widely used by people of various professions than the globe?
Cards have found wide use among people. Thanks to them, you can get acquainted with the terrain without direct contact with it. Maps are actively used as navigation aids in guidebooks for tourists, in ship navigation and even in astronautics! They are also needed in the development of mineral resources, in military affairs and construction. In other words, geographic maps are used in almost all areas.
3. How are directions to the sides of the horizon determined on a small-scale geographic map?
Small-scale maps include maps built on a scale smaller than 1:1,000,000. When creating a map, a strict selection is made of what will be depicted and written on it. On the map, directions are determined using a degree network.
The Earth's degree network is a system of meridians and parallels.
All points of one meridian have the same longitude, and all points of parallel have the same latitude. The smaller the scale of the map, the less often the lines of the degree network are drawn.
To determine the direction to a given object, you must use azimuth. Azimuth is the angle between the direction to the north and the direction to a given terrain object, the value of which is expressed in degrees and counted from north to the right, clockwise.
4. What needs to be done to determine the distance between objects on a geographic map?
To determine on a map the distance between terrain points (objects, objects), using a numerical scale, you need to measure on the map the distance between these points in centimeters and multiply the resulting number by the scale value.
For example, on a map of scale 1:50000 (scale size 500 m), the distance between two landmarks is 4.2 cm. Therefore, the required distance between these landmarks on the ground will be equal to 4.2 * 500 = 2100 m.
A small distance between two points in a straight line is easier to determine using a linear scale. To do this, it is enough to apply a measuring compass, the opening of which is equal to the distance between given points on the map, to a linear scale and take a reading in meters or kilometers.
We will learn the rules of working with contour maps, complete tasks on a contour map, and begin to draw up our own map of the world.
1. From the globe to geographical maps
Fill in the missing words in the definition.
Geographic maps are a reduced-scale image of the earth's surface that show the position, condition and connections of natural and social objects and phenomena.
2. Map scale
Compare the scales of the school globe and the maps of the hemispheres and Russia in the school atlas. Write down the scales in ascending order.
Conclusion. The scale of the image of the Earth on the globe is smaller (larger, smaller) than the scale of the image of the Earth on the map of the hemispheres.
3. Working with a geographic map
The arrows are directed along the lines of parallels, along the equator and latitude.
Determine the geographic coordinates of the points indicated on the map of the Eastern Hemisphere with a sign (.), and label them on the map.
Make sure that on the hemisphere map, the area of least distortion is in the central parts of the map circles.
Measure the extent of the Indian Ocean along the equator (I) in two ways.
I = (98°E - 42°E) × 111.3 km = 56° × 111.3 km = 6232.8 km
I = 5 cm: 1/200 = 5000 km
The value of lengths determined in two ways: ruler, degree grid.
Measure the extent of Russian territory along the parallel of 60° N. w. (P) in two ways.
1) According to the degree grid (true value of the length):
P = (170°E - 30°E) × 55.8 km = 140° × 55.8 km = 7840 km
2) Using a ruler and scale:
I = 14 cm: 1/200 = 14000 km
Length values determined in two ways: ruler, degree grid.
Identify geographic objects by coordinates. Fill out the table.
Using a map of Russia, using a ruler and scale, determine the distance from Moscow to the Azov and White Seas.
From Moscow to the Sea of Azov 1002 km.
From Moscow to the White Sea 835 km.
Compare the obtained values with the textbook data on those distances obtained when measured using grid lines.
Conclusion. Most accurate results measurements are obtained using a degree grid and calculations.
Geographer-Pathfinder School
