What are the Major Ice Ages of the Earth's History?

The Ice Age, also known as the Ice Age, refers to the period when the earth and the ocean were covered by ice in some years. These frozen areas are much wider than what is now frozen.

During the glacial period, the ice layer covered a large area of the world, and the climate in these areas was very cold; there were many ice cubes in the ocean, and the ground was condensed with thick ice. At the same time, as more water is stored in the ice, sea levels are lower everywhere. The ice age can last for more than one million years. The ice age has appeared 11 times since the formation of the earth. The last ice age is called the "Great Ice Age", which occurred 18,000 years ago and ended at 10,000. Years ago, about a third of the earth's land was covered by 240 meters of ice. During the Ice Age, the temperature dropped, changing the

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About 2.4 billion years ago, the concentration of oxygen in the atmosphere was sufficient to provide life needed for oxygen to survive. However, at that time, when the earth fell into the glacial period surrounded by snow and ice, some scientists estimated that the snow and ice at that time was about 800 meters deep, and it was quite difficult to imagine the scene at that time. Therefore, some scientists doubt whether complex life forms existed before such a icy and snowy environment and could survive this ice age. Or did complex life begin to evolve after these snow and ice melted?

When was last time? As the ice age approaches, the temperature decreases slowly and gradually. The most recent ice age occurred about 18,000 years ago. According to research by scientists, the climate was cold at the time, and about a third of the world's landmass covered 240 meters of ice. The earliest Great Ice Age on Earth occurred about 2.4 to 2.1 billion years ago, which is the middle of the Precambrian. The closest to us was 18,000 years ago, when the sea level fell to the edge of our current continental slope, which averaged 130 meters below the current sea level. In fact, what we mean by the continental shed is the remains of the glaciers at that time.

There have been two ice ages in world history. Before the first ice age, there were almost no evolved animals, only unevolved animals, and there was snow and ice everywhere. After the first ice age, great progress has been made, animals have grown huge, and they have passed through many generations. After the second ice age, large animals disappeared and replaced by smaller animals. This is the Paleozoic, Eocene, Oligocene.