A "Ice Age" presents the ancient ice age scene on the screen in an animated way.
We can't help but wonder, was the Earth's ice age really full of ice and snow?
In fact, the Earth has experienced a total of four major ice ages, namely the Karoo Ice, the Andean Sahara Ice, the Varangir Ice, and the Huron Ice.
This article is about 2.4 billion years ago ~ 2.1 billion years ago during the Huron Ice Age, where heavy snow fell for 300 million years one after another, and the whole world was covered with ice and snow, even around the equator, and the earth was like a super-large snowball.
Some people may wonder, how long has it been since we humans came out of Africa, at most 60,000~70,000 years, how can we know what happened 2.4 billion ~ 2.1 billion years ago?
This problem is not difficult to solve, for example, if you are burning a stick, even if the flame is extinguished and the flame is extinguished, you can roughly judge the time by the residual residual temperature.
Scientists have studied the sediments and found a large number of glacial sediments, which are also distributed around the equator, and the detection of glacial sediments by modern instruments can roughly determine the time of occurrence of the ice age.
Among the many ice ages that have occurred in the history of the earth, the Huron ice age is very special, it lasted for about 300 million years, that is, the earth has been snowing for the entire 300 million years, how did this happen? How did the Ice Age end?
First of all, we all know that the heat energy on the earth's surface comes from sunlight.
Sunlight is electromagnetic radiation, when sunlight hits the surface of an object, infrared energy will activate the movement of molecules and atoms inside the object, and the temperature will increase when the movement is violent.
However, sunlight is one of the manifestations of solar activity, and when there is a problem with nuclear fusion in the sun, the energy emitted by the sun may also be reduced, so the main cause of the earth's ice age may be that the solar activity has entered a trough.
In addition to the source factor, the intermediate heat transfer process is also one of the many factors, the sun is not fixed in the universe, it is also moving around the galactic center at a speed of 220 kilometers per second, the period is one galactic year, about 226 million years.
If the sun encounters a large amount of cosmic dust or other materials during its movement, blocking part of the sun's rays, the earth receives less heat energy, and the surface of the earth will be covered with ice and snow when the temperature drops.
Later, according to German scientist Daniel Herwartz, the main cause of the Huron Ice Age was related to the amount of oxygen on the earth.
About 3.4 billion years ago, cyanobacteria began to appear on Earth, and they belonged to the first group of organisms capable of photosynthesis.
Cyanobacteria convert carbon dioxide and water into organic matter and release oxygen through photosynthesis.
But it's important to know that carbon dioxide isn't exactly harmful, it's a type of greenhouse gas.
When there are more greenhouse gases, the surface temperature will rise, and when there are fewer greenhouse gases, the surface temperature will decrease.
At first, the number of cyanobacteria was small, and the impact on the earth's atmosphere was negligible, but after hundreds of millions of years of reproduction, cyanobacteria were overwhelming and full, so a large amount of carbon dioxide was converted into oxygen, so that the earth's greenhouse gases finally broke through the critical value, and the surface temperature began to decrease significantly.
Another problem arises when the surface is covered with snow, when sunlight hits the ground and is refracted back into space, it is absorbed and intercepted by greenhouse gases and then rebounds back to the ground, thus forming an insulating layer.
Greenhouse gases aside, the snow has a higher reflectivity of sunlight, even more than 90%, resulting in the heat energy of sunlight has no obvious heating effect on the snow, and the snow also firmly locks in the precious little heat energy of the ground.
Originally, there were more greenhouse gases, and the sunlight that was reflected off the snow could be reabsorbed and refracted to the surface, but under the action of cyanobacteria, the earth's greenhouse gases were thinner, and the sunlight could not be retained.
This led to a vicious cycle that led to the freezing of the ancient oceans of the Huron Ice Age, which was as thick as 300 meters, and the Earth remained covered in snow and ice for 300 million years.
If the Earth's ice age continues, it will be difficult to give birth to a large number of life forms, and the rate of evolution will be slow, but it turns out that the Huron Ice Age ended 2.1 billion years ago, what is the force that caused the world's glaciers to melt and revitalize the earth?
2.4 billion ~ 2.1 billion years ago, the solar activity did not change drastically, and the great force that really ended the ice age came from the earth.
At this stage, the earth's internal activity is violent, and the huge energy leads to frequent geological activities, a large number of volcanoes around the world continue to erupt, the heat energy in the earth's interior begins to gush out, and the sea temperature rises and begins to melt glaciers.
After the earth absorbed heat again, the ice age gradually ended, and after everything recovered, aerobic organisms began to rise, a large amount of oxygen was absorbed and carbon dioxide was produced, biological evolution began to accelerate, and the ecology gradually began to stabilize.
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