A geography expert comes in and asks about the longitude and latitude map

I think I’d better explain it to you. It’s hard to understand by yourself.

1. I don’t understand longitude and latitude lines. Can we talk about what are longitude lines, what are latitude lines, what are longitudes, and what are latitudes?

①Meridians are also called meridians. Like latitudes, they are auxiliary lines assumed by humans for the convenience of measurement. They are defined as arcs connecting the north and south poles on the earth's surface and perpendicular to the latitudes. All great circles on the earth formed by the plane passing through the earth's axis and intersecting the ground are called "meridian circles". The semicircles divided into two poles are called "meridians". Any two meridians of equal length intersect at the north and south poles. Each longitude line has its corresponding numerical value, called longitude. Meridians indicate north and south directions.

②The latitude line is perpendicular to the earth's axis and a circle that surrounds the earth. The equator is the largest circle of latitude.

Latitude refers to the line-plane angle formed by the line connecting a certain point to the center of the Earth and the Earth's equatorial plane. Its value ranges from 0 to 90 degrees. The latitude of a point located north of the equator is called northern latitude, denoted by N, and the latitude of a point located south of the equator is called southern latitude, denoted by S.

I will give you another table to compare and contrast

Longitudes

Latitudes

Definition

Connecting the North and South Poles The line of

A line parallel to the equator (perpendicular to the meridian)

Indicates the direction

North and south (S means south and N means north)

East and west (E means east and W means west)

Length

Equal

Unequal (the equator is the longest and shorter towards the poles)

Shape

A meridian is an arc, and two opposite ones form a circle

Each of them forms a circle

Interrelationship

Bringing together two points

Parallel to each other

2. Let’s take a look at what the east, west, south and north hemispheres are

We can group several hemispheres:

① In the eastern and western hemispheres, many people think that the dividing line between the eastern and western hemispheres is longitude 0° and 180°. This is not true. The correct division method should be 20° west longitude and 160° east longitude. The reason for this division is that these two The longitude lines pass through the least amount of land. For example: if place A is at 120° east longitude, then place A is located in the Eastern Hemisphere. If place B is at 60° west longitude, then place B is located in the Western Hemisphere. (As shown in the picture, you can take a good look at it. I originally wanted to send you a picture of the extreme day and night, but I only allow one to be uploaded here, so I will give you one. The picture is hand-drawn by myself)

< p>② Northern and Southern Hemispheres. Many people should have no doubt about this division. The equator is the dividing line. The north of the equator is called the Northern Hemisphere, and the south is called the Southern Hemisphere. I will not give examples.

3. Let’s take a look at what are low latitudes, middle latitudes and high latitudes

①Low latitude: We take the latitudes from 0° to 30° (both north and south latitudes, northern latitudes 30° to 30° south latitude) are called low latitudes.

② Mid-latitude: We call the latitudes from 30° to 60° (30° to 60° north latitude, 30° to 60° south latitude) as mid-latitudes.

③High latitude: We call the latitudes from 60° to 90° (60° to 90° north latitude, 60° to 90° south latitude) as high latitudes.

4. Let’s talk about the phenomenon of polar night and day.

Let’s briefly talk about it. The conditions for polar night and day are that the place must be located within the Arctic and Antarctic circles. This phenomenon only occurs in places.

①The so-called polar day means that the sun never sets and the sky is always bright. This phenomenon is also called white night; the so-called polar night means that it is the opposite of the polar day, the sun never comes out and the sky is always dark.

②The formation of polar day and polar night is caused by the fact that when the earth revolves around the sun in an elliptical orbit, it also rotates around its own tilted axis. It turns out that when the earth rotates, the earth's axis forms an inclination angle of about 23.5° with its vertical line. Therefore, when the earth rotates, for 6 months, one of the two poles always faces the sun and it is full daytime; the other pole faces away. Toward the sun, all is night.

5. Let’s take a look at the question you asked again

Place A is directly south of Land B. Let me tell you that the location of Land A is (30 degrees S, 40 degrees E) , what is the location of land B?

The location of place A is 30° south latitude and 40° east longitude. Place B is located directly south of place A. This means that place B is also on the longitude line of 40° east longitude. Due south, it means that place B is between 30° south latitude and 90° south latitude, then the coordinates of place B are (30°S-90°S, 40°E).