The hemisphere of the Earth. Characteristics and features

Our planet is conditionally divided into four hemispheres. How are the boundaries between them? What are the features of the hemisphere of the Earth?

Equator and meridian

The planet Earth has a shape slightly flattened at the poles of a sphere - a spheroid. In scientific circles, its form is usually called a geoid, that is, "like Earth." The surface of the geoid is perpendicular in the direction of gravity at any point.

For the convenience of characterizing the planet, conditional or imaginary lines are used. One of them is the axis. It passes through the center of the Earth, connecting the upper and lower parts, called the North and South Pole.

Between the poles, at an equal distance from them, lies the next imaginary line, called the equator. It is horizontal and is a separator to the South (all below the line) and the North (all above the line) hemisphere of the Earth. The length of the equator is just over 40 thousand kilometers.

Another conditional line is Greenwich, or zero, the meridian. This is a vertical line passing through the observatory in Greenwich. The meridian divides the planet into the Western and Eastern hemispheres, and is also the starting point for measuring geographic longitude.

The difference between the Southern and Northern Hemispheres

The equator line horizontally divides the planet in half, crossing several continents at the same time. Africa, Eurasia and South America are partially located in two hemispheres. The other continents are located within one. So, Australia and Antarctica are completely in the southern part, and North America - in the north.

The hemisphere of the Earth also has other differences. Thanks to the Arctic Ocean on the pole, the climate of the Northern Hemisphere is generally milder than the Southern one, where the land is located - Antarctica. Seasons on the hemispheres are the opposite: the winter in the northern part of the planet comes simultaneously with the summer in the south.

The difference is observed in the movement of air and water. To the north of the equator, river currents and sea currents deviate to the right (on the right banks of rivers are usually steeper), anticyclones rotate clockwise, and cyclones - against. To the south of the equator everything is exactly the opposite.

Even the starry sky above your head is different. The pattern in each hemisphere is different. The main reference point for the northern part of the Earth is the polar star, in the Southern Hemisphere the Southern Cross is the reference point. Above the equator, land predominates, so the majority of people live here. Below the equator, the total number of inhabitants is 10%, since the oceanic part prevails.

Western and Eastern hemispheres

To the east of the zero meridian is the Eastern hemisphere of the Earth. In its limits is Australia, most of Africa, Eurasia, part of Antarctica. About 82% of the world's population lives here. In the geopolitical and cultural sense, it is called the Old World, as opposed to the New World of the Americas. In the eastern part is the largest peninsula, deep trough and the highest mountain on our planet.

The western hemisphere of the Earth is in the west of the Greenwich meridian. It covers the North and South America, part of Africa and Eurasia. It completely includes the Atlantic Ocean and most of the Pacific. Here is the longest mountain chain in the world, the largest volcano, the driest desert, the highest mountain lake and a full-flowing river. Only 18% of the population lives in the western part of the world.

Date change line

As already mentioned, the Western and Eastern hemispheres of the Earth is divided by the Greenwich meridian. Its continuation is the 180th meridian, which delineates the border from the other side. It is the line of change of dates, it is here that today turns into tomorrow.

On both sides of the meridian are recorded different calendar days. This is due to the features of the rotation of the planet. The date line for most dates runs through the ocean, but also crosses some islands (Vanua Levu, Taviuni, etc.). In these places, for convenience, the line is shifted along the land border, otherwise the inhabitants of one island would exist in different dates.