Why did the Ice Age begin? Ice Ages. What causes an ice age

Consider such a phenomenon as periodic ice ages on Earth. In modern geology, it is generally accepted that our Earth periodically experiences Ice Ages in its history. During these epochs, the Earth's climate becomes sharply colder, and the Arctic and Antarctic polar caps monstrously increase in size. Not so many thousands of years ago, as we were taught, vast expanses of Europe and North America were covered with ice. Eternal ice lay not only on the slopes of high mountains, but also covered the continents with a thick layer even in temperate latitudes. Where the Hudson, the Elbe and the Upper Dnieper flow today, there was a frozen desert. All this was like an endless glacier, and now covers the island of Greenland. There are indications that the retreat of the glaciers has been halted by new ice masses and that their boundaries are in different time varied. Geologists can determine the boundaries of glaciers. Traces of five or six successive movements of ice during the ice age, or five or six ice ages, have been found. Some force pushed the ice layer to temperate latitudes. Until now, neither the cause of the appearance of glaciers, nor the cause of the retreat of the ice desert is known; the timing of this retreat is also a matter of dispute. Many ideas and conjectures have been put forward to explain how the ice age began and why it ended. Some have thought that the Sun radiated more or less heat in different epochs, which explains the periods of heat or cold on the Earth; but we do not have sufficient evidence that the Sun is such a "changing star" to accept this hypothesis. The cause of the ice age is seen by individual scientists in a decrease in the initial high temperature planets. Warm periods between glacial periods have been associated with heat released from the supposed decomposition of organisms in layers close to the earth's surface. The increase and decrease in the activity of hot springs were also taken into account.

Many ideas and conjectures have been put forward to explain how the ice age began and why it ended. Some have thought that the Sun radiated more or less heat in different epochs, which explains the periods of heat or cold on the Earth; but we do not have sufficient evidence that the Sun is such a "changing star" to accept this hypothesis.

Others have argued that in outer space there are colder and warmer zones. As our solar system passes through regions of cold, the ice descends in latitude closer to the tropics. But no physical factors have been found to create similar cold and warm zones in space.

Some have wondered whether precession, or the slow reversal of the earth's axis, could cause periodic fluctuations climate. But it has been proven that this change alone cannot be so significant as to cause an ice age.

Also, scientists were looking for an answer in periodic variations in the eccentricity of the ecliptic (earth's orbit) with the phenomenon of glaciation at maximum eccentricity. Some researchers believed that winter in aphelion, the most distant part of the ecliptic, could lead to glaciation. And others believed that summer at aphelion could cause such an effect.

The reason for the Ice Age is seen by some scientists as a decrease in the initially high temperature of the planet. Warm periods between glacial periods have been associated with heat released from the supposed decomposition of organisms in layers close to the earth's surface. The increase and decrease in the activity of hot springs were also taken into account.

There is a point of view that the dust of volcanic origin filled earth's atmosphere and caused isolation, or, on the other hand, the increasing amount of carbon monoxide in the atmosphere prevented the reflection of heat rays from the surface of the planet. An increase in the amount of carbon monoxide in the atmosphere can cause a drop in temperature (Arrhenius), but calculations have shown that this could not be the true cause of the ice age (Angstrom).

All other theories are also hypothetical. The phenomenon that underlies all these changes has never been precisely defined, and those that were named could not produce a similar effect.

Not only are the reasons for the appearance and subsequent disappearance of ice sheets unknown, but the geographic relief of the area covered with ice remains a problem. Why is the ice cover southern hemisphere moving from tropical regions of Africa towards the south pole, and not in the opposite direction? And why in the northern hemisphere did ice move into India from the equator towards the Himalayas and higher latitudes? Why did glaciers cover most North America and Europe, while North Asia was free from them?

In America, the ice plain extended up to a latitude of 40° and even went beyond this line, in Europe it reached a latitude of 50°, and North-Eastern Siberia, above the Arctic Circle, even at a latitude of 75° was not covered by this eternal ice. All hypotheses regarding the increasing and decreasing isolation associated with the change of the sun or temperature fluctuations in outer space, and other similar hypotheses, cannot but encounter this problem.

Glaciers formed in permafrost regions. For this reason, they remained on the slopes of high mountains. The north of Siberia is the coldest place on Earth. Why did the ice age not touch this area, although it covered the Mississippi basin and all of Africa south of the equator? No satisfactory answer to this question has been offered.

During the Last Ice Age, at the peak of the glaciation, which was observed 18,000 years ago (on the eve of the Great Flood), the borders of the glacier in Eurasia passed along approximately 50 ° north latitude (latitude of Voronezh), and the border of the glacier in North America even along 40 ° (latitude New York). At the South Pole, glaciation took over southern South America, and possibly also New Zealand and southern Australia.

The theory of ice ages was first presented in the work of the father of glaciology, Jean Louis Agassiz, "Etudes sur les glaciers" (1840). Over the past century and a half, glaciology has been replenished with a huge amount of new scientific data, and the maximum boundaries of the Quaternary glaciation were determined from a high degree accuracy.
However, for the entire time of the existence of glaciology, it failed to establish the most important thing - to determine the causes of the onset and retreat of ice ages. None of the hypotheses put forward so far has been approved. scientific community. And today, for example, in the Russian-language Wikipedia article “Ice Age” you will not find the section “Causes of Ice Ages”. And not because this section was forgotten to be placed here, but because no one knows these reasons. What are the real reasons?
Paradoxically, in fact, there have never been any ice ages in the history of the Earth. The temperature and climate regime of the Earth is set mainly by four factors: the intensity of the Sun's glow; orbital distance of the Earth from the Sun; the angle of inclination of the axial rotation of the Earth to the plane of the ecliptic; as well as the composition and density of the earth's atmosphere.

These factors, as scientific data show, remained stable throughout at least the last Quaternary period. Therefore, no reason for abrupt change The climate of the Earth was not in the direction of cooling.

What is the reason for the monstrous growth of glaciers during the Last Ice Age? The answer is simple: in the periodic change in the location of the earth's poles. And here it should immediately be added: the monstrous growth of the Glacier during the Last Ice Age is an apparent phenomenon. In fact, the total area and volume of the Arctic and Antarctic glaciers has always remained approximately constant - while the Northern and South Pole but changed their position with an interval of 3,600 years, which predetermined the wandering of polar glaciers (caps) on the surface of the Earth. Exactly as much glacier formed around the new poles as it melted in those places where the poles left. In other words, the Ice Age is a very relative concept. When the North Pole was in North America, there was an ice age for its inhabitants. When the North Pole moved to Scandinavia, the Ice Age began in Europe, and when the North Pole “left” into the East Siberian Sea, the Ice Age “came” to Asia. An ice age is currently in full swing for the supposed inhabitants of Antarctica and the former inhabitants of Greenland, which is constantly melting in the southern part, as the previous pole shift was not strong and moved Greenland a little closer to the equator.

Thus, there have never been ice ages in the history of the Earth, and at the same time they have always been. Such is the paradox.

The total area and volume of glaciation on the planet Earth has always been, is and will be generally constant as long as the four factors that determine the climate regime of the Earth are constant.
During the pole shift, there are several ice sheets on the Earth at the same time, usually two melting and two newly formed - this depends on the angle of crustal displacement.

Pole shifts on Earth occur at intervals of 3,600-3,700 years, corresponding to the orbital period of Planet X around the Sun. These pole shifts lead to a redistribution of heat and cold zones on Earth, which is reflected in modern academic science in the form of continuously replacing each other stadials (cooling periods) and interstadials (warming periods). Average duration both stadials and interstadials is defined in modern science at 3700 years, which correlates well with the period of revolution of Planet X around the Sun - 3600 years.

From academic literature:

It must be said that in the last 80,000 years the following periods were observed in Europe (years BC):
Stadial (cooling) 72500-68000
Interstadial (warming) 68000-66500
Stadial 66500-64000
Interstadial 64000-60500
Stadial 60500-48500
Interstadial 48500-40000
Stadial 40000-38000
Interstadial 38000-34000
Stadial 34000-32500
Interstadial 32500-24000
Stadial 24000-23000
Interstadial 23000-21500
Stadial 21500-17500
Interstadial 17500-16000
Stadial 16000-13000
Interstadial 13000-12500
Stadial 12500-10000

Thus, in the course of 62 thousand years, 9 stadials and 8 interstadials happened in Europe. The average duration of a stadial is 3700 years, and an interstadial is also 3700 years. The largest stadial lasted 12,000 years, and the interstadial lasted 8,500 years.

In the post-Flood history of the Earth, 5 pole shifts occurred and, accordingly, 5 polar ice sheets successively replaced each other in the Northern Hemisphere: the Laurentian ice sheet (the last antediluvian), the Scandinavian Barents-Kara ice sheet, the East Siberian ice sheet, the Greenland ice sheet and the modern Arctic ice sheet.

The modern Greenland Ice Sheet deserves special attention as the third major ice sheet coexisting simultaneously with the Arctic Ice Sheet and the Antarctic Ice Sheet. The presence of a third large ice sheet does not contradict the above theses, since it is a well-preserved remnant of the previous North Polar Ice Sheet, where the North Pole was located during 5200-1600 years. BC. Connected with this fact is the answer to the riddle why the extreme north of Greenland today is not affected by glaciation - the North Pole was in the south of Greenland.

Accordingly, the location of the polar ice sheets in the southern hemisphere changed:

• 16,000 BCuh. (18,000 years ago) recent times there is a strong consensus in academic science regarding the fact that this year was both the peak of the maximum glaciation of the Earth and the beginning of the rapid melting of the Glacier. A clear explanation of neither one nor the other fact in modern science does not exist. What was this year famous for? 16,000 BC e. - this is the year of the 5th passage through the solar system, counting from the present moment ago (3600 x 5 = 18,000 years ago). This year, the North Pole was located on the territory of modern Canada in the Hudson Bay area. The South Pole was located in the ocean to the east of Antarctica, which suggested the glaciation of southern Australia and New Zealand. Bala's Eurasia is completely free of glaciers. “In the 6th year of K'an, the 11th day of Muluk, in the month of Sak, a terrible earthquake began and continued without interruption until 13 Kuen. The Land of the Clay Hills, the Land of Mu, was sacrificed. Having experienced two strong vibrations, she suddenly disappeared during the night;the soil was constantly shaking under the influence of underground forces, which raised and lowered it in many places, so that it settled; countries were separated from one another, then scattered. Unable to resist these terrible shudders, they failed, dragging the inhabitants with them. This happened 8050 years before this book was written.”("Code Troano" translated by Auguste Le Plongeon). The unprecedented magnitude of the catastrophe caused by the passage of Planet X has resulted in a very strong pole shift. The North Pole moves from Canada to Scandinavia, the South Pole to the ocean west of Antarctica. At the same time that the Laurentian Ice Sheet begins to melt rapidly, which coincides with the data of academic science about the end of the peak of glaciation and the beginning of the melting of the Glacier, the Scandinavian Ice Sheet is formed. At the same time, the Australian and South Zealand ice sheets melt and the Patagonian Ice Sheet forms in South America. These four ice sheets coexist for only a relatively short time, which is necessary for the two previous ice sheets to completely melt and two new ones to form.

• 12,400 BC The North Pole is moving from Scandinavia to the Barents Sea. In this regard, the Barents-Kara ice sheet is formed, but the Scandinavian ice sheet is melting only slightly, as the North Pole moves a relatively small distance. In academic science, this fact has found the following reflection: “The first signs of an interglacial period (which is still ongoing) appeared as early as 12,000 BC.”
• 8 800 BC The North Pole is moving out Barents Sea in the East Siberian, in connection with which the Scandinavian and Barents-Kara ice sheets are melting, and the East Siberian ice sheet is formed. This pole shift killed off most of the mammoths. Quote from an academic study: “About 8000 BC. e. a sharp warming led to the departure of the glacier from its last line - a wide strip of moraines stretching from central Sweden through the basin Baltic Sea southeast of Finland. Approximately at this time, the disintegration of a single and homogeneous periglacial zone occurs. In the temperate zone of Eurasia, forest vegetation predominates. To the south of it, forest-steppe and steppe zones are formed.
• 5 200 BC The North Pole is moving from the East Siberian Sea to Greenland, causing the East Siberian Ice Sheet to melt and the Greenland Ice Sheet to form. Hyperborea is freed from ice, and a wonderful temperate climate is established in the Trans-Urals and Siberia. Ariavarta, the country of the Aryans, flourishes here.
• 1600 BC Past shift. The North Pole is moving from Greenland to the North Arctic Ocean to its present position. The Arctic Ice Sheet emerges, but the Greenland Ice Sheet remains at the same time. The last mammoths living in Siberia freeze very quickly with undigested green grass in the stomachs. Hyperborea is completely hidden under the modern Arctic ice sheet. Most of the Trans-Urals and Siberia become unsuitable for human existence, which is why the Aryans undertake their famous Exodus to India and Europe, and the Jews also make their exodus from Egypt.

“In the permafrost of Alaska ... one can find ... evidence of atmospheric disturbances of incomparable power. Mammoths and bison were torn apart and twisted as if some cosmic arms of the gods were acting in rage. In one place ... they found the front leg and shoulder of a mammoth; the blackened bones still held the remnants of soft tissues adjacent to the spine along with tendons and ligaments, and the chitinous sheath of the tusks was not damaged. There were no traces of dismemberment of carcasses with a knife or other tool (as would be the case if hunters were involved in the dismemberment). The animals were simply torn apart and scattered around the area like woven straw, although some of them weighed several tons. Mixed with clusters of bones are trees, also torn, twisted and tangled; all this is covered with fine-grained quicksand, subsequently tightly frozen” (G. Hancock, “Traces of the Gods”).

Frozen mammoths

Northeastern Siberia, which was not covered by glaciers, holds another mystery. The climate in it has changed dramatically since the end of the ice age, and mean annual temperature fell many degrees lower than before. The animals that once lived in the area could no longer live here, and the plants that used to grow there were no longer able to grow here. Such a change must have happened quite suddenly. The reason for this event is not explained. During this catastrophic climate change and under mysterious circumstances, all Siberian mammoths perished. And it happened only 13 thousand years ago, when the human race was already widespread throughout the planet. For comparison: cave drawings Late Paleolithic, found in the caves of Southern France (Lascaux, Chauvet, Rouffignac, etc.), were made 17-13 thousand years ago.

Such an animal lived on earth - a mammoth. They reached a height of 5.5 meters and a body weight of 4-12 tons. Most of the mammoths died out about 11-12 thousand years ago during the last cooling of the Vistula Ice Age. This is what science tells us, and draws a picture like the one above. True, not very concerned about the question - what did these elementary people eat? woolly elephants weighing 4-5 tons on such a landscape. “Of course, since it’s written in books like that”- Allen nod. Reading very selectively, and considering the given picture. About the fact that during the life of mammoths on the territory of the current tundra, birch grew (which is written in the same book, and other deciduous forests - that is, a completely different climate) - they somehow do not notice. The diet of mammoths was mainly vegetable, and adult males daily ate about 180 kg of food.

While the number of woolly mammoths was truly impressive. For example, between 1750 and 1917, the mammoth ivory trade flourished over a wide area, and 96,000 mammoth tusks were discovered. According to various estimates, in a small part northern Siberia There were about 5 million mammoths.

Before their extinction, woolly mammoths inhabited vast parts of our planet. Their remains have been found throughout Northern Europe, Northern Asia and North America.

Woolly mammoths were not a new species. They have inhabited our planet for six million years.

Biased interpretation of the hairy and fatty constitution of the mammoth, as well as belief in unchanging climatic conditions led scientists to conclude that woolly mammoth was an inhabitant of the cold regions of our planet. But fur-bearing animals do not have to live in cold climates. Take for example desert animals like camels, kangaroos and phoenixes. They are furry but live in hot or temperate climates. In fact most fur-bearing animals would not be able to survive in arctic conditions.

For successful cold adaptation, it is not enough just to have a coat. For adequate thermal insulation from the cold, the coat should be in an elevated state. Unlike Antarctic fur seals, mammoths lacked raised fur.

Another factor of sufficient protection against cold and humidity is the presence of sebaceous glands, which secrete oils on the skin and fur, and thus protect against moisture.

Mammoths did not have sebaceous glands, and their dry hair allowed the snow to touch the skin, melt, and significantly increase heat loss (the thermal conductivity of water is about 12 times higher than that of snow).

As seen in the photo above, mammoth fur was not dense. In comparison, the fur of a yak (a cold-adapted Himalayan mammal) is about 10 times thicker.

In addition, mammoths had hair that hung down to their toes. But every arctic animal has hair on its toes or paws, not hair. Hair would collect snow on the ankle joint and interfere with walking.

The above clearly shows that fur and body fat are not proof of cold adaptation. The fat layer only indicates the abundance of food. A fat, overfed dog would not have been able to withstand an arctic blizzard and a temperature of -60°C. But arctic rabbits or caribou can, despite their relatively low fat content relative to total body weight.

As a rule, the remains of mammoths are found with the remains of other animals, such as: tigers, antelopes, camels, horses, reindeer, giant beavers, giant bulls, sheep, musk oxen, donkeys, badgers, alpine goats, woolly rhinos, foxes, giant bison, lynx, leopard, wolverine, hares, lions, elks, giant wolves, gophers, cave hyenas, bears, and many bird species. Most of these animals would not be able to survive in arctic climate. This is additional evidence that woolly mammoths were not polar animals.

The French prehistoric expert, Henry Neville, made the most detailed study of mammoth skin and hair. At the end of his careful analysis, he wrote the following:

"It is not possible for me to find in the anatomical study of their skin and [hair] any argument in favor of adaptation to cold."

— G. Neville, On the Extinction of the Mammoth, Smithsonian Institution Annual Report, 1919, p. 332.

Finally, the diet of mammoths contradicts the diet of animals living in polar climates. How could a woolly mammoth maintain its vegetarian diet in an arctic region, and eat hundreds of pounds of greens every day when, in such a climate, most of the year there is none at all? How could woolly mammoths find liters of water for daily consumption?

To make matters worse, woolly mammoths lived during the Ice Age, when temperatures were cooler than they are today. Mammoths would not have been able to survive in the harsh climate of northern Siberia today, let alone 13,000 years ago, if the then climate had been much harsher.

The above facts indicate that the woolly mammoth was not a polar animal, but lived in a temperate climate. Consequently, at the beginning of the Younger Dryas, 13 thousand years ago, Siberia was not an arctic region, but a temperate one.

"A long time ago, however, they died"- the reindeer breeder agrees, cutting off a piece of meat from the found carcass in order to feed the dogs.

"Hard"- says a more vital geologist, chewing a piece of barbecue taken from a makeshift skewer.

Frozen mammoth meat initially looked absolutely fresh, dark red in color, with appetizing streaks of fat, and the expedition even wanted to try to eat it. But as it thawed, the meat became flabby, dark gray in color, with an unbearable smell of decomposition. However, the dogs happily ate the millennial ice cream delicacy, from time to time arranging internecine fights over the most tidbits.

One more moment. Mammoths are rightly called fossils. Because in our time they are simply dug. For the purpose of obtaining tusks for crafts.

It is estimated that for two and a half centuries in the north-east of Siberia, tusks belonging to at least forty-six thousand (!) mammoths were collected (the average weight of a pair of tusks is close to eight pounds - about one hundred and thirty kilograms).

Mammoth tusks are DIGGING. That is, they are mined from underground. Somehow, the question does not even arise - why have we forgotten how to see the obvious? Mammoths dug holes for themselves, lay down in them on hibernation, and then they fell asleep? But how did they end up underground? At a depth of 10 or more meters? Why are mammoth tusks dug from river banks? And, massively. So massively that a bill was submitted to the State Duma equating mammoths with minerals, as well as introducing a tax on their extraction.

But for some reason they are digging massively only here in the north. And now the question arises - what happened that whole mammoth cemeteries were formed here?

What caused such an almost instantaneous mass pestilence?

Over the past two centuries, numerous theories have been proposed that attempt to explain the sudden extinction of woolly mammoths. They got stuck in frozen rivers, were over-hunted, and fell into ice crevices at the height of the global glaciation. But none of the theories adequately explains this mass extinction.

Let's try to think for ourselves.

Then the following logical chain should line up:

1. There were a lot of mammoths.
2. Since there were a lot of them, they should have had a good food base - not the tundra, where they are now found.
3. If it was not the tundra, the climate in those places was somewhat different, much warmer.
4. A slightly different climate OUTSIDE the Arctic Circle could only be if it was not TRANSArctic at that time.
5. Mammoth tusks, and whole mammoths themselves, are found underground. They somehow got there, some event occurred that covered them with a layer of soil.
6. Taking it as an axiom that mammoths themselves did not dig holes, only water could bring this soil, first surging, and then descending.
7. The layer of this soil is thick - meters, and even tens of meters. And the amount of water that applied such a layer must have been very large.
8. Mammoth carcasses are found in a very well-preserved condition. Immediately after washing the corpses with sand, their freezing followed, which was very fast.

They almost instantly froze on giant glaciers, the thickness of which was many hundreds of meters, to which they were carried by a tidal wave caused by a change in the angle of the earth's axis. This gave rise to the unjustified assumption among scientists that the animals of the middle belt went deep into the North in search of food. All remains of mammoths were found in sands and clays deposited by mud flows.

Such powerful mudflows are possible only during extraordinary major disasters, because at that time dozens, and possibly hundreds and thousands of animal cemeteries were formed throughout the North, into which not only the inhabitants were washed away northern regions, but also animals from regions with a temperate climate. And this allows us to believe that these giant animal cemeteries were formed by a tidal wave of incredible power and size, which literally rolled over the continents and retreating back into the ocean, carried away thousands of herds of large and small animals with it. And the most powerful mudflow “tongue”, containing giant accumulations of animals, reached the New Siberian Islands, which were literally covered with loess and countless bones of various animals.

A giant tidal wave washed away gigantic herds of animals from the face of the Earth. These huge herds drowned animals, lingering in natural barriers, terrain folds and floodplains, and formed countless animal cemeteries, in which animals of various climatic zones appeared to be mixed.

Scattered bones and molars of mammoths are often found in sediments and sedimentary rocks at the bottom of the oceans.

The most famous, but far from the largest cemetery of mammoths in Russia, is the Berelekh burial. Here is how N.K. describes the mammoth cemetery in Berelekh. Vereshchagin: “Yar is crowned with a melting edge of ice and mounds ... A kilometer later, an extensive scattering of huge gray bones appeared - long, flat, short. They protrude from the dark damp ground in the middle of the slope of the ravine. Sliding down to the water along a slightly turfed slope, the bones formed a spit-toe protecting the shore from erosion. There are thousands of them, the scattering stretches along the coast for about two hundred meters and goes into the water. The opposite, right bank is only eighty meters away, low, alluvial, behind it is an impenetrable willow growth ... everyone is silent, depressed by what they saw ".In the area of ​​the Berelekh cemetery there is a thick layer of clay-ash loess. Signs of an extremely large floodplain sediment are clearly traced. In this place, a huge mass of fragments of branches, roots, bone remains of animals has accumulated. The animal cemetery was washed away by the river, which, twelve millennia later, returned to its former course. Scientists who studied the Berelekh cemetery found among the remains of mammoths a large number of bones of other animals, herbivores and predators, which in normal conditions never found in huge clusters together: foxes, hares, deer, wolves, wolverines and other animals.

The theory of repeated catastrophes that destroy life on our planet and repeat the creation or restoration of life forms, proposed by Deluc and developed by Cuvier, did not convince the scientific world. Both Lamarck before Cuvier and Darwin after him believed that a progressive, slow, evolutionary process governs genetics and that there are no catastrophes that interrupt this process of infinitesimal changes. According to the theory of evolution, these minor changes are the result of adaptation to the conditions of life in the struggle of species for survival.

Darwin admitted that he was unable to explain the disappearance of the mammoth, an animal much better developed than the elephant, which survived. But in accordance with the theory of evolution, his followers believed that the gradual subsidence of the soil forced the mammoths to climb the hills, and they turned out to be swamps closed on all sides. However, if geological processes are slow, mammoths would not be trapped on isolated hills. Besides, this theory cannot be true, because the animals did not die of starvation. Undigested grass was found in their stomachs and between their teeth. This, by the way, also proves that they died suddenly. Further research showed that the branches and leaves found in their stomachs do not grow in the areas where the animals died, but further south, at a distance of more than a thousand miles. It seems that the climate has changed radically since the death of the mammoths. And since the bodies of animals are found not decomposed, but well preserved in ice blocks, a change in temperature must have followed immediately after their death.

Documentary

Risking their lives and being exposed great danger scientists in Siberia are looking for a single frozen mammoth cell. With the help of which it will be possible to clone and thereby bring back to life a long-extinct animal species.

It remains to be added that after storms in the Arctic, mammoth tusks are carried to the shores of the Arctic islands. This proves that the part of the land where the mammoths lived and drowned was heavily flooded.

For some reason, modern scientists do not take into account the facts of the presence of a geotectonic catastrophe in the recent past of the Earth. It is in the recent past.
Although for them it is already an indisputable fact of the catastrophe from which the dinosaurs died. But they attribute this event to the times of 60-65 million years ago.
There are no versions that would combine the temporary facts of the death of dinosaurs and mammoths - at the same time. Mammoths lived in temperate latitudes, dinosaurs - in the southern regions, but died at the same time.
But no, no attention is paid to the geographic attachment of animals of different climatic zones, but there is still a temporary separation.
The facts of the sudden death of a huge number of mammoths in different parts of the world have already accumulated a lot. But here the scientists again stray from the obvious conclusions.
Not only did the representatives of science age all the mammoths by 40 thousand years, but they also invent versions of the natural processes in which these giants died.

American, French and Russian scientists have performed the first CT scans of Luba and Khroma, the youngest and best preserved mammoths.

Computed tomography (CT) slices were presented in the new issue of the Journal of Paleontology, and a summary of the results of the work can be found on the website of the University of Michigan.

Reindeer herders found Lyuba in 2007, on the banks of the Yuribey River on the Yamal Peninsula. Her corpse reached the scientists with almost no damage (only the tail was bitten off by dogs).

Chrome (this is a "boy") was discovered in 2008 on the banks of the river of the same name in Yakutia - crows and arctic foxes ate his trunk and part of his neck. Mammoths have well-preserved soft tissues (muscles, fat, internal organs, skin). Chroma was even found to have clotted blood in intact vessels and undigested milk in her stomach. The chroma was scanned in a French hospital. And at the University of Michigan, scientists took CT scans of animal teeth.

Thanks to this, it turned out that Lyuba died at the age of 30-35 days, and Khroma - 52-57 days (both mammoths were born in the spring).

Both mammoths died, choking on silt. CT scans showed a dense mass of fine-grained deposits obstructing the airways in the trunk.

The same deposits are present in Lyuba's throat and bronchi - but not inside the lungs: this suggests that Lyuba did not drown in water (as was previously believed), but suffocated, inhaling liquid mud. Chroma had a broken spine and also had dirt in his airways.

So, scientists once again confirmed our version of a global mudflow that covered the current north of Siberia and destroyed everything living there, covering a vast territory with “fine-grained sediments that clogged the respiratory tract.”

After all, such finds are observed over a vast territory and it is absurd to assume that all the mammoths found at the same time and massively began to fall into rivers and swamps.

Plus, mammoths have typical injuries for those caught in a stormy mudflow - fractures of bones and spine.

Scientists have found very interesting detail- death occurred either in late spring or summer. After birth in the spring, mammoths lived until death for 30-50 days. That is, the time of the change of poles was probably in the summer.

Or here's another example:

A team of Russian and American paleontologists is studying a bison that has lain in permafrost in northeastern Yakutia for about 9,300 years.

The bison, found on the shores of Lake Chukchala, is unique in that it is the first representative of this species of bovids, found at such a venerable age in complete safety - with all parts of the body and internal organs.

He was found in a recumbent position with his legs bent under his belly, his neck outstretched, and his head lying on the ground. Usually in this position, ungulates rest or sleep, but in it they die a natural death.

The age of the body, determined using radiocarbon analysis, is 9310 years, that is, the bison lived in the early Holocene. Scientists also determined that his age before his death was about four years. The bison managed to grow up to 170 cm at the withers, the span of the horns reached an impressive 71 cm, and the weight was about 500 kg.

Researchers have already scanned the animal's brain, but the cause of his death is still a mystery. No injuries were found on the corpse, as well as no pathologies of internal organs and dangerous bacteria.

In the history of the Earth, there were long periods when the entire planet was warm - from the equator to the poles. But there were also times so cold that glaciations reached those regions that currently belong to temperate zones. Most likely, the change of these periods was cyclical. AT warm times ice could be relatively scarce, and it was found only in the polar regions or on the tops of mountains. An important feature of ice ages is that they change the nature earth's surface: Each glaciation affects the appearance of the Earth. By themselves, these changes may be small and insignificant, but they are permanent.

History of Ice Ages

We don't know exactly how many ice ages there have been throughout Earth's history. We know of at least five, possibly seven, ice ages, starting with the Precambrian, in particular: 700 million years ago, 450 million years ago (Ordovician), 300 million years ago - Permo-Carboniferous glaciation, one of the largest ice ages, affecting the southern continents. Under southern continents refers to the so-called Gondwana - an ancient supercontinent that included Antarctica, Australia, South America, India and Africa.

The most recent glaciation refers to the period in which we live. Quaternary period cenozoic era began about 2.5 million years ago, when the glaciers of the Northern Hemisphere reached the sea. But the first signs of this glaciation date back 50 million years ago in Antarctica.

The structure of each ice age is periodic: there are relatively short warm epochs, and there are longer periods of icing. Naturally, cold periods are not the result of glaciation alone. Glaciation is the most obvious consequence of cold periods. However, there are quite long intervals that are very cold, despite the absence of glaciations. Today, examples of such regions are Alaska or Siberia, where it is very cold in winter, but there is no glaciation, because there is not enough rainfall to provide enough water for the formation of glaciers.

Discovery of ice ages

The fact that there are ice ages on Earth has been known to us since the middle of the 19th century. Among the many names associated with the discovery of this phenomenon, the first is usually the name of Louis Agassiz, a Swiss geologist who lived in the middle of the 19th century. He studied the glaciers of the Alps and realized that they were once much more extensive than they are today. It wasn't just him who noticed. In particular, Jean de Charpentier, another Swiss, also noted this fact.

It is not surprising that these discoveries were made mainly in Switzerland, since there are still glaciers in the Alps, although they are melting quite quickly. It is easy to see that once the glaciers were much larger - just look at the Swiss landscape, troughs (glacial valleys) and so on. However, it was Agassiz who first put forward this theory in 1840, publishing it in the book "Étude sur les glaciers", and later, in 1844, he developed this idea in the book "Système glaciare". Despite initial skepticism, over time, people began to realize that this was indeed true.

With the advent of geological mapping, especially in northern Europe, it became clear that earlier glaciers were of enormous scale. Then there were extensive discussions about how this information relates to the Flood, because there was a conflict between geological evidence and biblical teachings. Initially, glacial deposits were called deluvial because they were considered evidence Flood. Only later it became known that such an explanation did not fit: these deposits were evidence of a cold climate and extensive glaciation. By the beginning of the 20th century, it became clear that there were many glaciations, and not just one, and from that moment this area of ​​​​science began to develop.

Ice Age Research

Known geological evidence of ice ages. The main evidence for glaciations comes from the characteristic deposits formed by glaciers. They are preserved in the geological section in the form of thick ordered layers of special deposits (sediments) - diamicton. These are simply glacial accumulations, but they include not only deposits of a glacier, but also deposits of melt water formed by its flows, glacial lakes or glaciers moving into the sea.

There are several forms of glacial lakes. Their main difference is that they are a water body enclosed by ice. For example, if we have a glacier that rises into a river valley, then it blocks the valley like a cork in a bottle. Naturally, when ice blocks a valley, the river will still flow and the water level will rise until it overflows. Thus, a glacial lake is formed through direct contact with ice. There are certain deposits that are contained in such lakes that we can identify.

Because of how the glaciers are melting, which depends on seasonal changes temperature, annual ice melting occurs. This leads to an annual increase in minor sediments falling from under the ice into the lake. If we then look into the lake, we see stratification (rhythmic layered sediments) there, which is also known by the Swedish name "varves" (varve), which means "annual accumulations". So we can actually see annual layering in glacial lakes. We can even count these varves and find out how long this lake has existed. In general, with the help of this material, we can get a lot of information.

In Antarctica, we can see huge ice shelves that come off the land into the sea. And of course, ice is buoyant, so it floats on water. As it swims, it carries pebbles and minor sediments with it. Due to the thermal action of the water, the ice melts and sheds this material. This leads to the formation of the process of the so-called rafting of rocks that go into the ocean. When we see fossil deposits from this period, we can find out where the glacier was, how far it extended, and so on.

Causes of glaciation

Researchers believe that ice ages occur because the Earth's climate depends on the uneven heating of its surface by the Sun. So, for example, the equatorial regions, where the Sun is almost vertically overhead, are the warmest zones, and the polar regions, where it is at a large angle to the surface, are the coldest. This means that the difference in heating of different parts of the Earth's surface controls the ocean-atmospheric machine, which is constantly trying to transfer heat from the equatorial regions to the poles.

If the Earth were an ordinary sphere, this transfer would be very efficient, and the contrast between the equator and the poles would be very small. So it was in the past. But since there are now continents, they get in the way of this circulation, and the structure of its flows becomes very complex. Simple currents are restrained and altered, in large part by mountains, leading to the circulation patterns we see today that drive the trade winds and ocean currents. For example, one of the theories about why the ice age began 2.5 million years ago links this phenomenon with the emergence of Himalayan mountains. The Himalayas are still growing very fast and it turns out that the existence of these mountains in a very warm part of the Earth governs things like the monsoon system. The beginning of the Quaternary Ice Age is also associated with the closing of the Isthmus of Panama, which connects the north and south of America, which prevented the transfer of heat from the equatorial Pacific to the Atlantic.

If the location of the continents relative to each other and relative to the equator allowed the circulation to work efficiently, then it would be warm at the poles, and relatively warm conditions would persist throughout the earth's surface. The amount of heat received by the Earth would be constant and vary only slightly. But since our continents create serious barriers to circulation between north and south, we have pronounced climatic zones. This means that the poles are relatively cold while the equatorial regions are warm. When things are happening as they are now, the Earth can change with variations in the amount of solar heat it receives.

These variations are almost completely constant. The reason for this is that over time the earth's axis changes, as does the earth's orbit. Given this complex climatic zoning, orbital change could contribute to long-term changes in climate, resulting in climate wobble. Because of this, we have not continuous icing, but periods of icing, interrupted by warm periods. This happens under the influence of orbital changes. The latest orbital changes are seen as three separate phenomena: one 20,000 years long, the second 40,000 years long, and the third 100,000 years long.

This led to deviations in the pattern of cyclic climate change during the Ice Age. The icing most likely occurred during this cyclic period of 100,000 years. The last interglacial epoch, which was as warm as the current one, lasted about 125,000 years, and then came a long ice epoch, which took about 100,000 years. We are now living in another interglacial era. This period will not last forever, so another ice age awaits us in the future.

Why do ice ages end?

Orbital changes change the climate, and it turns out that ice ages are characterized by alternating cold periods, which can last up to 100,000 years, and warm periods. We call them the glacial (glacial) and interglacial (interglacial) epochs. The interglacial era is usually characterized by approximately the same conditions that we observe today: high level seas, limited areas of icing and so on. Naturally, even now there are glaciations in Antarctica, Greenland and other similar places. But in general, the climatic conditions are relatively warm. This is the essence of interglacial: high sea level, warm temperature conditions and, in general, a fairly even climate.

But during the ice age, the average annual temperature changes significantly, the vegetative belts are forced to shift north or south, depending on the hemisphere. Regions like Moscow or Cambridge become uninhabited, at least in winter. Although they may be habitable in the summer due to the strong contrast between the seasons. But what is actually happening is that the cold zones are expanding substantially, the average annual temperature is dropping, and the overall climate is getting very cold. While the largest glacial events are relatively limited in time (perhaps around 10,000 years), the entire long cold period can last 100 thousand years or even more. This is what the glacial-interglacial cycle looks like.

Due to the length of each period, it is difficult to say when we will exit the current era. This is due to plate tectonics, the location of the continents on the surface of the Earth. Currently, the North Pole and South Pole are isolated, with Antarctica at the South Pole and the Arctic Ocean to the north. Because of this, there is a problem with heat circulation. As long as the location of the continents does not change, this ice age will continue. In line with long-term tectonic changes, it can be assumed that it will take another 50 million years in the future until significant changes occur that allow the Earth to emerge from the ice age.

Geological implications

This frees up huge sections of the continental shelf that are flooded today. This will mean, for example, that one day it will be possible to walk from Britain to France, from New Guinea to Southeast Asia. One of the most critical places is the Bering Strait, which connects Alaska with Eastern Siberia. It is quite small, about 40 meters, so if the sea level drops to a hundred meters, then this area will become land. This is also important because plants and animals will be able to migrate through these places and get into regions where they cannot go today. Thus, the colonization of North America depends on the so-called Beringia.

Animals and the Ice Age

It is important to remember that we ourselves are the "products" of the ice age: we evolved during it, so we can survive it. However, it is not a matter of individual individuals - it is a matter of the entire population. The problem today is that there are too many of us and our activities have significantly changed the natural conditions. AT vivo many of the animals and plants that we see today have a long history and survive the ice age well, although there are those that evolved slightly. They migrate and adapt. There are zones in which animals and plants survived the Ice Age. These so-called refugiums were located further north or south from their current distribution.

But as a result of human activity, some species died or became extinct. This has happened on every continent, with the possible exception of Africa. A huge number of large vertebrates, namely mammals, as well as marsupials in Australia, were exterminated by man. This was caused either directly by our activities, such as hunting, or indirectly by the destruction of their habitat. Animals living in northern latitudes today, in the past lived in the Mediterranean. We have destroyed this region so much that it will most likely be very difficult for these animals and plants to colonize it again.

Consequences of global warming

Under normal conditions, by geological standards, we would soon enough return to the Ice Age. But because of global warming, which is a consequence of human activity, we are postponing it. We will not be able to completely prevent it, since the causes that caused it in the past still exist today. Human activity, an unforeseen element of nature, affects atmospheric warming, which may have already caused a delay in the next glacial.

Today, climate change is a very relevant and exciting issue. If the Greenland Ice Sheet melts, sea levels will rise by six meters. In the past, during the previous interglacial epoch, which was about 125,000 years ago, the Greenland Ice Sheet melted profusely, and sea levels were 4–6 meters higher than today. It's certainly not the end of the world, but it's not time complexity either. After all, the Earth has recovered from catastrophes before, it will be able to survive this one.

The long-term outlook for the planet is not bad, but for humans, that's a different matter. The more research we do, the better we understand how the Earth is changing and where it leads, the better we understand the planet we live on. This is important because people are finally starting to think about changing sea levels, global warming and the impact of all these things on agriculture and the population. Much of this has to do with the study of ice ages. Through these studies, we will learn the mechanisms of glaciation, and we can use this knowledge proactively in an attempt to mitigate some of the changes that we ourselves are causing. This is one of the main results and one of the goals of research on ice ages.
Of course, the main consequence of the Ice Age is huge ice sheets. Where does water come from? Of course, from the oceans. What happens during ice ages? Glaciers form as a result of precipitation on land. Due to the fact that the water does not return to the ocean, the sea level falls. During the most severe glaciations, sea levels can drop by more than a hundred meters.

Just at the time of the powerful development of all forms of life on our planet, a mysterious ice age begins with its new temperature fluctuations. We have already spoken about the reasons for the appearance of this ice age before.

Just as the change of seasons brought about the selection of better, more adaptable animals and the creation of diverse breeds of mammals, so now, in this Ice Age, man is emerging from the mammals, in an even more painful struggle against the advancing glaciers than the fight against the millennium-spanning change of seasons. Here it was not enough just one adaptation by a significant change in the body. What was needed was a mind that would be able to turn nature itself to its advantage and conquer it.

We have finally reached the highest stage of the development of life: . He took possession of the Earth, and his mind, developing further and further, learned to embrace the entire universe. With the advent of man, a completely new era of creation truly began. We are still on one of its lower levels, we are the simplest among beings endowed with a mind that dominates the forces of nature. The beginning of the path to unknown majestic goals has come!

There have been at least four great ice ages, which, in turn, break up again into smaller waves of temperature fluctuations. Warmer periods lay between the ice ages; then, thanks to the melting glaciers, the damp valleys were covered with lush meadow vegetation. Therefore, it was during these interglacial periods that herbivores could develop especially well.

In the deposits of the Quaternary epoch, which closes the ice ages, and in the deposits of the Deluvian epoch, which followed the last general glaciation the globe, and the direct continuation of which is our time, we come across huge pachyderms, namely the mammoth mastodon, the fossilized remains of which we still often find in the tundra of Siberia. Even with this giant, the primitive man dared to get involved in the struggle, and, in the end, he emerged victorious from it.

Mastodon (restored) of the Deluvian era.

We involuntarily return in thought again to the emergence of the world, if we look at the flowering of the beautiful present from the chaotic dark primitive conditions. The fact that in the second half of our investigations we remained all the time only on our small Earth is due to the fact that we know all these different stages of development only on it. But, taking into account the similarity of the matter that forms the world everywhere and the universality of the forces of nature that control matter, we will come to complete agreement of all the main features of the formation of the world that we can observe in the sky.

We have no doubt that in the distant universe there must be millions more worlds like our Earth, although we do not have any exact information about them. On the contrary, it is among the relatives of the Earth, the rest of the planets of our solar system, which we can better explore, due to their greater proximity to us, there are characteristic differences from our Earth, as, for example, sisters of very different ages. Therefore, we should not be surprised if we do not find traces of life on them, similar to the life of our Earth. Also, Mars with its channels remains a mystery to us.

If we look up at the sky strewn with millions of Suns, then we can be sure that we will meet the gazes of living beings who look at our daylight in the same way we look at their Sun. Perhaps we are not so far from the time when, having mastered all the forces of nature, a person will be able to penetrate into these expanses of the universe and send a signal beyond our globe to living beings located on another celestial body - and receive an answer from them .

Just as life, at least otherwise we cannot imagine it, came to us from the universe and spread over the Earth, starting with the simplest, so man, in the end, will expand the narrow horizon that encompasses him. earthly world, and will communicate with other worlds of the universe, from where these primary elements of life on our planet came. The universe belongs to man, his mind, his knowledge, his strength.

But no matter how high fantasy lifts us, we will someday fall down again. The cycle of development of the worlds consists in rise and fall.

ice age on earth

After terrible downpours, like a flood, it became damp and cold. From the high mountains, the glaciers slid lower and lower into the valleys, because the Sun could no longer melt the masses of snow continuously falling from above. As a result of this, even those places where the temperature was still above zero during the summer were also covered with ice for a long time. We are now seeing something similar in the Alps, where individual "tongues" of glaciers descend well below the boundary of eternal snows. In the end, much of the plains at the foot of the mountains were also covered with ever higher piles of ice. A general ice age has come, the traces of which we can indeed observe everywhere on the entire globe.

It is necessary to recognize the enormous merit of the world traveler Hans Meyer from Leipzig for the evidence he found that both on Kilimanjaro and on the Cordillera of South America, even in tropical regions, glaciers everywhere at that time descended much lower than at present. The connection here between that extraordinary volcanic activity and the onset of the ice age was first proposed by the Sarazen brothers in Basel. How did this happen?

The following question can be answered after careful research. The entire chain of the Andes, during geological periods, which, of course, are calculated in hundreds of thousands and millions of years, was formed simultaneously, and its volcanoes were the result of this grandiose mountain-forming process on Earth. At this time, almost the entire Earth was dominated by approximately tropical temperature, which, however, very soon after that should have been replaced by a strong general cooling.

Penk established that there were at least four great ice ages, with warmer periods in between. But it seems that these great ice ages are divided into a still greater number of smaller periods of time in which more insignificant general temperature fluctuations took place. From this one can see what turbulent times the Earth was going through and in what constant agitation the air ocean was then.

How long this time lasted can only be indicated very roughly. It has been calculated that the beginning of this ice age can be placed about half a million years ago. Since the last “little glaciation”, in all likelihood, only 10 to 20 millennia have passed, and we are now living, probably, only in one of those “interglacial periods” that happened before the last general glaciation.

Through all these ice ages there are traces primitive man that develops from an animal. The legends about the flood, which have come down to us from primitive times, may stand in connection with the events described above. The Persian legend almost certainly points to volcanic phenomena that preceded the beginning of the great flood.

This Persian legend describes the great flood as follows: “From the south rose a great fiery dragon. Everything was devastated by him. Day turned into night. The stars are gone. The zodiac was covered by a huge tail; only the sun and moon could be seen in the sky. Boiling water fell to the Earth and scorched the trees to the very roots. Raindrops the size of a human head fell among the frequent lightning. Water covered the Earth higher than a man's height. Finally, after the dragon fight lasted 90 days and 90 nights, the enemy of the Earth was destroyed. A terrible storm arose, the water receded, the dragon plunged into the depths of the Earth.

This dragon, according to the famous Viennese geologist Suess, was nothing more than a highly active volcano, the fiery eruption of which spread across the sky like a long tail. All other phenomena described in the legend are quite consistent with the phenomena observed after a strong volcanic eruption.

Thus, on the one hand, we have shown that after the splitting and collapse of a huge block, the size of a mainland, a series of volcanoes should have formed, the eruptions of which were followed by floods and glaciations. On the other hand, we have before our eyes a series of volcanoes in the Andes, located along a huge cliff of the Pacific coast, and we also proved that soon after the emergence of these volcanoes, an ice age began. The tales of the flood complete the picture of this turbulent period in the development of our planet even more. During the eruption of Krakatoa, we observed on a small scale, but in all details, the consequences of the volcano sinking into the depths of the sea.

Taking into account all of the above, we will hardly doubt that the relationship between these phenomena was, indeed, such as we assumed. Thus, the entire Pacific Ocean, indeed, arose as a result of the separation and failure of its present bottom, which until then was a huge continent. Was it "the end of the world" in the sense that it is commonly understood? If the fall happened suddenly, then it was probably the most terrible and grandiose catastrophe that the Earth has ever seen since organic life appeared on it.

This question is now, of course, difficult to answer. But still we can say the following. Had a landslide on the coast Pacific Ocean occurred gradually, then those terrible volcanic eruptions would remain completely inexplicable, which at the end of the “Tertiary era” occurred along the entire chain of the Andes and whose very weak consequences are still observed there.

If the coastal region were to sink there so slowly that it would take centuries to detect this sinking, as we still observe at the present time in some sea ​​shores, then even then all the movements of masses in the interior of the Earth would be very slow, and only occasionally volcanic eruptions would occur.

In any case, we see that there are counteractions to these forces that produce shifts in the earth's crust, otherwise the sudden tremors of earthquakes could not take place. But we had also to admit that the tensions resulting from these counteractions cannot become too great, because Earth's crust turns out to be plastic, malleable for large, but slowly acting forces. All these considerations lead us to the conclusion, perhaps against our will, that these catastrophes must have manifested precisely sudden forces.

State educational institution higher professional education Moscow region

International University of Nature, Society and Man "Dubna"

Faculty of Natural and Engineering Sciences

Department of Ecology and Earth Sciences

COURSE WORK

By discipline

Geology

Scientific adviser:

Candidate of G.M.S., Associate Professor Anisimova O.V.

Dubna, 2011

Introduction

1. Ice age

1.1 Ice Ages in Earth's History

1.2 Proterozoic ice age

1.3 Paleozoic Ice Age

1.4 Cenozoic Ice Age

1.5 Tertiary period

1.6 Quaternary period

2. The Last Ice Age

2.2 Flora and fauna

2.3Rivers and lakes

2.4 West Siberian lake

2.5Oceans

2.6 Great Glacier

3. Quaternary glaciations in the European part of Russia

4. Causes of Ice Ages

Conclusion

Bibliography

Introduction

Target:

To study the main ice ages in the history of the Earth and their role in shaping the modern landscape.

Relevance:

The relevance and significance of this topic is determined by the fact that the glacial epochs are not so well studied to fully confirm the existence on our Earth.

Tasks:

- conduct a literature review;

- establish the main ice ages;

– obtaining detailed data on the last Quaternary glaciations;

Establish the main causes of glaciation in the history of the Earth.

At present, there is still little data that confirms the distribution of frozen rock strata on our planet in ancient epochs. The proof is mainly the discovery of ancient continental glaciations in their moraine deposits and the establishment of the phenomena of mechanical separation of the rocks of the glacier bed, the transfer and processing of detrital material and its deposition after ice melting. Compacted and cemented ancient moraines, the density of which is close to sandstone-type rocks, are called tillites. The discovery of such formations of different ages in different regions of the globe clearly indicates the repeated appearance, existence and disappearance of ice sheets, and, consequently, frozen strata. The development of ice sheets and frozen strata can occur asynchronously, i.e. the maximum development over the area of ​​glaciation and cryolithozone may not coincide in phase. However, in any case, the presence of large ice sheets indicates the existence and development of frozen strata, which should occupy much larger areas than the ice sheets themselves.

According to N.M. Chumakov, as well as V.B. Harland and M.J. Hambry, the time intervals during which glacial deposits were formed are called glacial eras (lasting the first hundreds of millions of years), ice ages (millions - the first tens of millions of years), ice ages (the first millions of years). In the history of the Earth, the following glacial eras can be distinguished: Early Proterozoic, Late Proterozoic, Paleozoic and Cenozoic.

1. Ice age

Are there ice ages? Of course yes. The evidence for this is incomplete, but it is well established, and some of this evidence extends over large areas. Evidence for the existence of the Permian Ice Age is present on several continents, and in addition, traces of glaciers have been found on the continents dating back to other epochs of the Paleozoic era up to its beginning, the Early Cambrian time. Even in much older rocks, pre-Phanerozoic, we find traces left by glaciers and glacial deposits. Some of these footprints are over two billion years old, perhaps half the age of the Earth as a planet.

Glacial epoch of glaciations (glacials) - time interval geological history Earth, characterized by a strong cooling of the climate and the development of extensive continental ice not only in the polar, but also in temperate latitudes.

Peculiarities:

It is characterized by a long, continuous and severe cooling of the climate, the growth of ice sheets in the polar and temperate latitudes.

· Glacial epochs are accompanied by a decrease in the level of the World Ocean by 100 m or more, due to the fact that water accumulates in the form of ice sheets on land.

·During glacial epochs, the areas occupied by permafrost are expanding, soil and vegetation zones are shifting towards the equator.

It has been established that over the past 800 thousand years there have been eight glacial epochs, each of which lasted from 70 to 90 thousand years.

Fig.1 Ice age

1.1 Ice Ages in Earth's History

Periods of climate cooling, accompanied by the formation of continental ice sheets, are recurring events in the history of the Earth. The intervals of cold climate during which extensive continental ice sheets and sediments lasting hundreds of millions of years are formed are called ice ages; in glacial eras, glacial periods lasting tens of millions of years are distinguished, which, in turn, consist of glacial epochs - glaciations (glacials) alternating with interglacials (interglacials).

Geological studies have proved that there was a periodic process of climate change on Earth, covering the time from the late Proterozoic to the present.

These are relatively long ice ages that lasted for almost half of the history of the Earth. The following ice ages are distinguished in the history of the Earth:

Early Proterozoic - 2.5-2 billion years ago

Late Proterozoic - 900-630 million years ago

Paleozoic - 460-230 million years ago

Cenozoic - 30 million years ago - present

Let's consider each of them in more detail.

1.2 Proterozoic Ice Age

Proterozoic - from the Greek. the words proteros - primary, zoe - life. Proterozoic era - a geological period in the history of the Earth, including the history of formation rocks various origins from 2.6 to 1.6 billion years. A period in the history of the Earth, which was characterized by the development of the simplest forms of life of unicellular living organisms from prokaryotes to eukaryotes, which later evolved into multicellular organisms as a result of the so-called Ediacaran "explosion".

Early Proterozoic Ice Age

This is the oldest glaciation recorded in geological history at the end of the Proterozoic on the border with the Vendian, and according to the Snowball Earth hypothesis, the glacier covered most of the continents at equatorial latitudes. In fact, it was not one, but a series of glaciations and interglacial periods. Since it is believed that nothing can prevent the spread of glaciation due to an increase in albedo (reflection of solar radiation from the white surface of glaciers), it is believed that the subsequent warming can be caused, for example, by an increase in the amount of greenhouse gases in the atmosphere due to an increase in volcanic activity , accompanied, as is well known, by emissions of a huge amount of gases.

Late Proterozoic Ice Age

It was distinguished under the name of the Lapland glaciation at the level of the Vendian glacial deposits 670-630 million years ago. These deposits are found in Europe, Asia, West Africa, Greenland and Australia. The paleoclimatic reconstruction of the glacial formations of this time suggests that the European and African ice continents of that time were a single ice sheet.

Fig.2 Vend. Ulytau during the Ice Age Snowball

1.3 Paleozoic Ice Age

Paleozoic - from the word paleos - ancient, zoe - life. Palaeozoic. Geological time in the history of the Earth covering 320-325 million years. With an age of glacial deposits of 460-230 million years, it includes the Late Ordovician - Early Silurian (460-420 million years), Late Devonian (370-355 million years) and Carboniferous-Permian ice ages (275 - 230 million years). The interglacial period of these periods is characterized by a warm climate, which contributed to rapid development vegetation. Large and unique coal basins and horizons of oil and gas fields later formed in the places of their distribution.

Late Ordovician - Early Silurian Ice Age.

Glacial deposits of this time, called the Saharan (after the name of the modern Sahara). were distributed throughout modern Africa, South America, Eastern North America and Western Europe. This period is characterized by the formation of an ice sheet over much of northern, northwestern, and western Africa, including the Arabian Peninsula. Paleoclimatic reconstructions suggest that the thickness of the Saharan ice sheet reached at least 3 km and is similar in area to the modern glacier of Antarctica.

Late Devonian Ice Age

Glacial deposits of this period were found on the territory of modern Brazil. The glacial region extended from the modern mouth of the river. Amazons to east coast Brazil, capturing the Niger region in Africa. In Africa, in Northern Niger, tillites (glacial deposits) occur, which are comparable to those in Brazil. In general, glacial regions stretched from the border of Peru with Brazil to northern Niger, the diameter of the region was more than 5000 km. The South Pole in the Late Devonian, according to the reconstruction of P. Morel and E. Irving, was in the center of Gondwana in Central Africa. Glacial basins are located on the oceanic margin of the paleocontinent, mainly at high latitudes (not north of the 65th parallel). Judging by the then high-latitude continental position of Africa, one can assume the possible widespread development of frozen rocks on this continent and, moreover, in the northwest of South America.

The last ice age ended 12,000 years ago. In the most severe period, glaciation threatened man with extinction. However, after the glacier melted, he not only survived, but also created a civilization.

Glaciers in the history of the Earth

The last ice age in the history of the Earth is the Cenozoic. It began 65 million years ago and continues to this day. Modern man is lucky: he lives in the interglacial, in one of the warmest periods of the planet's life. Far behind is the most severe ice age - the Late Proterozoic.

Despite global warming, scientists are predicting a new ice age. And if the real one comes only after millennia, then the Little Ice Age, which will reduce by 2-3 degrees annual temperatures, could come pretty soon.

The glacier became a real test for man, forcing him to invent means for his survival.

last ice age

The Würm or Vistula glaciation began about 110,000 years ago and ended in the tenth millennium BC. The peak of cold weather fell on the period of 26-20 thousand years ago, the final stage of the Stone Age, when the glacier was the largest.

Little Ice Ages

Even after the glaciers melted, history has known periods of noticeable cooling and warming. Or, in other words, climate pessimism and optima. Pessima are sometimes referred to as Little Ice Ages. In the XIV-XIX centuries, for example, the Little Ice Age began, and the time of the Great Migration of Peoples was the time of the early medieval pessimum.

Hunting and meat food

There is an opinion according to which the human ancestor was rather a scavenger, since he could not spontaneously occupy a higher ecological niche. And all known tools were used to butcher the remains of animals that were taken from predators. However, the question of when and why a person began to hunt is still debatable.

In any case, thanks to hunting and eating meat, the ancient man received a large supply of energy, which allowed him to better endure the cold. The skins of slaughtered animals were used as clothing, shoes and walls of the dwelling, which increased the chances of surviving in a harsh climate.

bipedalism

Bipedalism appeared millions of years ago, and its role was much more important than in the life of a modern office worker. Having freed his hands, a person could engage in intensive construction of a dwelling, the production of clothing, the processing of tools, the extraction and preservation of fire. Upright ancestors moved freely in open areas, and their life no longer depended on the collection of fruits. tropical trees. Already millions of years ago, they freely moved over long distances and obtained food in river flows.

Walking upright played an insidious role, but it became more of an advantage. Yes, man himself came to cold regions and adapted to life in them, but at the same time he could find both artificial and natural shelters from the glacier.

Fire

fire in life ancient man was initially an unpleasant surprise, not a boon. Despite this, the ancestor of man first learned to “extinguish” it, and only later to use it for his own purposes. Traces of the use of fire are found in sites that are 1.5 million years old. This made it possible to improve nutrition through the preparation of protein foods, as well as to remain active at night. This further increased the time to create conditions for survival.

Climate

The Cenozoic Ice Age was not a continuous glaciation. Every 40 thousand years, the ancestors of people had the right to a “respite” - temporary thaws. At this time, the glacier receded, and the climate became milder. During periods of harsh climate, natural shelters were caves or regions rich in flora and fauna. For example, the south of France and the Iberian Peninsula were home to many early cultures.

The Persian Gulf 20,000 years ago was a river valley rich in forests and herbaceous vegetation, a truly “antediluvian” landscape. Wide rivers flowed here, exceeding the size of the Tigris and Euphrates by one and a half times. Sahara in separate periods became wet savannah. Last time this happened 9000 years ago. This can be confirmed by the rock paintings, which depict the abundance of animals.

Fauna

Huge glacial mammals such as bison, woolly rhinoceros and mammoth became an important and unique source of food for ancient people. Hunting such large animals required a lot of coordination and brought people together noticeably. The effectiveness of "collective work" has shown itself more than once in the construction of parking lots and the manufacture of clothing. Deer and wild horses among ancient people enjoyed no less "honor".

Language and communication

Language was, perhaps, the main life hack of an ancient person. It was thanks to speech that important technologies for processing tools, mining and maintaining fire, as well as various human adaptations for everyday survival, were preserved and transmitted from generation to generation. Perhaps in the Paleolithic language, the details of the hunt for large animals and the direction of migration were discussed.

Allerd warming

Until now, scientists are arguing whether the extinction of mammoths and other glacial animals was the work of man or caused by natural causes - the Allerd warming and the disappearance of forage plants. As a result of the extermination a large number species of animals, a person in harsh conditions was threatened with death from lack of food. There are known cases of the death of entire cultures simultaneously with the extinction of mammoths (for example, the Clovis culture in North America). Nevertheless, warming has become an important factor in the migration of people to regions whose climate has become suitable for the emergence of agriculture.