> the sea in ancient times was pure and transparent, and the four of them dived forty or fifty meters, and their bodies were still wrapped in sparkling streamers.

Occasionally, small fish swim by, and the sea seems very calm.

Along the way, beneath you is a delicate sand beach that stretches towards the bottom of the sea, and the soft white sand looks crystal bright.

As we progressed, the sand became less and less visible, and more rocks were revealed.

From 3,000 meters from the coastline, a large number of cracks appeared on the seabed, and only a small number of corals grew on it, obviously this area is a section of geological activity, and the violent compression between the plates has caused the uplift of the high mountains on the shore and a large number of fractures in the rock layers on the seabed.

As the cracks increased, the situation at the bottom of the sea became complicated, there was no light here, and the four of them could only observe left and right with their divine sense.

More and more trenches appeared around them, swimming fish and sea turtles came and went, and an octopus was startled by the four, and with a flick of its long whiskers, it spewed out a stream of ink, and the octopus fled in the opposite direction.

The environment of the four people has become quite embarrassing, these ravines are deep and shallow, the shallow ones can perceive the creatures at the bottom of the ditch, and the deep ones are long and long, they are suspended on them, which is equivalent to becoming a target in the light, if there are really aliens lurking around, it is extremely unsafe now.

Except for Yuan Yuanzi, everyone sensed the crisis, Zhang Binhui turned around and twisted, leading everyone to escape into a gentle trench.

"We need eyes and ears, otherwise it's dangerous to stay here."

Yuan Yuanzi nodded, and she released a large number of stealth balls from the bracelet, and the color of these spheres immediately faded, and they quickly disappeared into the seawater.

It didn't take long for the four of them to reveal images within their protective barriers, which were detected by the invisibility ball, and now, they were able to predict what was happening around them in advance.

The situation in this sea area is a little better than previously planned, most of the trenches are actually not too deep, one gully is a little deeper, and two stealth balls are slowly poking in.

An hour later, four people left the place. This area of tens of thousands of square kilometers has been explored by them, and they have found the remains of some sea beasts, perhaps the skins shed by the aliens, but other than that, the four of them have found nothing.

Following the direction of the submarine ravine, everyone sneaked all the way to the north, and the seabed topography did not change much, and there were still ravines everywhere.

After a whole day, several people found a hidden place to rest, and Hou Yi suddenly remembered a question:

"Brother Xiaohui, didn't I hear you talk about the battle of Gonggong Zhurong? Their war is taking place after us, in another era of humanity. ”

Zhang Binhui nodded, he didn't react to why Hou Yi remembered this matter.

Hou Yi then asked: "If I'm not mistaken, at that time you said that the great war between them ended the Ice Age ahead of schedule, causing a large number of volcanic eruptions, which eventually led to the arrival of the Great Flood.

The question is, our time in this era should not be far from them, and our environment is very warm now, right? How did those glaciers come from? ”

Zhang Binhui was stunned.

This thing is really wrong, the Ice Age led to the extinction of a large number of organisms, it is reasonable to not have started now, is the historical record wrong?

After thinking about it carefully, Zhang Binhui was puzzled, and next to her, Yuan Yuanzi took out a piece of jade slip like a treasure, and she looked very proud:

"Don't worry, I have prepared for the "Earth Treasure Book", which basically records all the major events that have happened on the earth, just check it out."

This is Yuan Yuanzi's little secret, she is simple by nature, and insists on the idea that if you love someone, you have to care about everything about him, so after arriving on Earth, she has been collecting relevant information, and she didn't expect that she has played an important role today.

"The Fourth Ice Age is the last great glacial period in the history of the earth, and it is also the most recent glacial period.

Glaciers occur because of the huge bodies of ice that move along the ground in polar or alpine regions, formed by gravity and tremendous pressure from large amounts of snow that fall above the snow line.

Glaciers receive a large amount of ice from the source, and this ice melts very slowly, and the glacier itself grows wide and deep, and flows down to the high temperatures, and the ice supply decreases, and the glacier becomes smaller and smaller, until the amount of ice melt cancels out the amount of recharge upstream.

Generally, glaciers are tongue-shaped, and the glacier surface is often uneven, and there are deep cracks in some places, that is, ice crevasses.

Glaciers can be divided into two main categories: continental glaciers and mountain glaciers. During the Quaternary period, the glaciers of the European Alps expanded at least five times.

In my country, hee-hee, in fact, is your country, there are scientists who have studied, and correspondingly there have been four subglacial periods in Poyang, Dagu, Lushan and Dali.

Modern glaciers cover a total area of about 16.3 million square kilometers, or 11% of the Earth's total land area. China's modern glaciers are mainly distributed in the Himalayas (northern slope), Kunlun Mountains, Tianshan Mountains, Qilian Mountains and some peak areas of the Hengduan Mountains, with a total area of about 57,069 square kilometers. ”

"With such a large area? Why is there no sign of cold at all now? ”

Not only Zhang Binhui, but also Kuafu and Hou Yi next to him were stunned, and Hou Yi laughed even more:

"Brother Xiaohui, I said your prediction is not accurate, right? Where can you see glaciers now? What a good temperature we have here! ”

Zhang Binhui was also a little dumbfounded: Could it be that he missed it? Or is this history wrong?

Yuan Yuanzi continued to read: "In the Quaternary Great Ice Age, we already know that the climate is still alternating between cold and warm.

The number of glaciers moving and retreating around the world during this time has not been consistent, but most scholars agree:

In the Quaternary, most of the Northern Hemisphere had four glacial periods, three interglacial periods, and one late glacial period; In Northern Europe, there are five glacial periods, four interglacial periods, and one postglacial period.

The Quaternary is the period of the emergence and development of human beings, so some people call it the Anthropocene.

It is generally believed that the Quaternary ape-man developed from the Meso-Pliocene Ramapicus. Early ape-man began to appear in the Early Pleistocene, represented by the Homo sapiens of the Audwe Gorge in Tanzania.

The stratigraphic age of Homo sapiens fossils is relatively old, and the late ape-man is represented by Peking ape and Javanese ape-man, who lived in the Middle Pleistocene.

In the late Middle Pleistocene, human beings developed to the early Homo sapiens stage, such as the Dingcun people, Maba people, Changyang people in China, etc., and Europe was represented by Neanderthals.

Late Homo sapiens appeared in the late Pleistocene, including the Hetao people, the mountaintop cave people, the Ziyang people, the Liujiang people, etc., and the Croomanon people in Europe.

At the height of the glacier in the fourth quarter, continental ice sheets were formed in the high latitudes of the Northern Hemisphere, the Greenland Ice Sheet covered Greenland and Iceland, and the Laurentian Ice Sheet buried all of Canada and extended south to New York and Cincinnati. Nearly half of Europe is covered by the Scandinavian ice sheet. The Siberian ice sheet occupies the northern part of Siberia. ”