To understand the earth, we must speak from the root. The earth is a planet we all know well. It is located in the solar system and is about 150 million kilometers away from the sun. The earth is a celestial body composed of rock, soil, and water, and its outer surface is covered with an atmosphere of about 150 kilometers thick.
Earth atmosphere
The earth is an approximately spherical ellipsoid, its equator radius is 6378.16 kilometers, the polar radius is 6356.77 kilometers, the equator circumference is 40000 kilometers, the mass of the earth is about 59.8 trillion tons, the surface of the earth is about 59.8 trillion tons. The area of and is about 510 million square kilometers.
The age of the earth is 4.65 billion years old, and it brings seasonal changes throughout the year to the earth. It takes a little more than a year to complete one revolution, which is 365 days, 6 hours, 9 minutes and 10 seconds, but people are used to 365 days count. It takes one day, or 23.93 hours, to rotate once.
The earth's surface is composed of land and ocean , the ocean area accounts for about 3/4, and the land area is about 1/4. Earth is a veritable water polo. The topography of the earth's surface is both landforms, consisting of mountains, plains, deserts, rivers, oceans, glaciers, etc. There are many animals living on the ground, and all kinds of plants are scattered throughout, and we are also living on the earth. a member.
From the perspective of the globe, the distribution of land and sea in the world is extremely uneven. The land is mainly distributed in the northern hemisphere , and the ocean is mainly distributed in the southern hemisphere . From the perspective of the eastern hemisphere and the western hemisphere, the land is mainly distributed in the eastern hemisphere, and the ocean is mainly distributed in the western hemisphere. Let's take a closer look at the distribution of land and sea on Earth.
Continent : That is, the vast and complete land on the earth. There are a total of 6 continents on the earth, namely Eurasia, Africa , North America, South America , Antarctica and Australia .Among them, the Eurasian continent includes two continents, Asia and Europe and .
Peninsula : refers to the land extending into the ocean or lake , one side is connected to the mainland, and the other three sides are surrounded by water. The large peninsulas are mainly formed by the rifting of geological structures, such as China's Liaodong Peninsula, Shandong Peninsula, and Leizhou Peninsula. In addition, due to the accumulation of sediment from the land to the island by the coastal sediment flow, or the erosion of the island from the island to the land, the debris material accumulates from the island to the land, gradually connecting the island and the mainland, forming land-land-island , Shandong Province, China The Zhifu Island is such an island. From the distribution point of view, most of the peninsulas in the world are distributed on the edge of the continent.
Island: An island is a naturally formed land that is scattered in oceans, rivers or lakes and is surrounded by water and exposed at high tide. If two or more islands are concentrated in a small area, they are called " island groups ", and the archipelagos arranged in columns are called "islands". And if all the territory of a country is located on an island, then the country is called an island country.
Four oceans cold knowledge
1, Pacific : The ocean with the widest area, the largest depth, the edge sea and the most islands in the world's oceans. The maximum length of the Pacific Ocean from north to south is about 15,900 kilometers, and the maximum width from east to west is about 109,900 kilometers. The total area is 178.68 million square kilometers, accounting for one-third of the earth's surface area and one-half of the world's ocean area. The average depth is 3957 meters, and the maximum depth is 11034 meters. There are more than 60,000 meters of trenches in the world, all concentrated in the Pacific Ocean. The seawater capacity of the Pacific Ocean is 707.1 million cubic kilometers, ranking first in the world's oceans.
Pacific
2, Atlantic Ocean: the second largest ocean in the world.Located between the South, North America and Europe, Africa, and Antarctica, it is a north-south, "s"-shaped ocean belt. It is about 15,000 kilometers long from north to south and narrow from east to west, with a maximum width of 2,800 kilometers. The total area is about 91.66 million square kilometers, slightly more than half the area of the Pacific Ocean. The average depth is 3,626 meters, and the deepest point is 9,219 meters. It is located in the Puerto Rico Trench.
Atlantic
3, Indian Ocean : the third largest ocean in the world. Located between Asia, Oceania , Africa and Antarctica. The area is about 76.17 million square kilometers, the average depth is 3397 meters, and the maximum depth of the Java Trench is 7450 meters. In the middle of the ocean floor, there are sea ridges in a roughly north-south direction.
Indian Ocean
4, Arctic Ocean : Located in the northernmost part of the earth, roughly centered on the Arctic , between Asia, Europe and the north coast of North America, it is the ocean with the smallest area, volume and shallowest depth among the four oceans.
Arctic Ocean
