Climatic changes were most pronounced in periodically advancing glacial periods, which had a significant impact on the conversion of the surface of the sushi under the body of the glacier, water objects and biological objects in the zone of the influence of the glacier.
According to the latest scientific data, the duration of glacial er on Earth is at least a third of all the time of its evolution for the last 2.5 billion years. And if we take into account the long initial phases of the origin of the glaciation and its gradual degradation, then the epochs of the glaces will take almost the same time as warm, rudely, conditions. The last of the glacial periods began almost a million years ago, at a quaternary time, and was marked by the extensive spread of glaciers - the great glaciation of the Earth. Under the powerful cover of ice, the northern part of the North American continent, a significant part of Europe, and possibly Siberia is also also. In the southern hemisphere under the ice, as well as now, there was all Antarctic mainland.
The main causes of glaestations are:
cosmic;
astronomical;
geographical.
Space groups of reasons:
changing the amount of heat on Earth due to the passage of the solar system 1 time / 186 million through the cold zones of the Galaxy;
changes in the amount of heat obtained by the Earth due to the decrease in solar activity.
Astronomical groups of reasons:
changing the position of the poles;
the slope of the earth's axis to the plane of the ecliptic;
change the eccentricity of the Earth orbit.
Geological and geographical groups of reasons:
climate change and the amount of carbon dioxide in the atmosphere (increase in carbon dioxide - warming; reduction - cooling);
changes in the directions of oceanic and air flows;
intensive process of mountain formation.
The conditions of manifestation of glaciation on Earth include:
the fallout of snow in the form of precipitation under conditions of low temperatures with its accumulation as a material for increasing the glacier;
negative temperatures in areas where there are no glaciations;
periods of intense volcanism due to the huge amount of ash ejected by volcanoes, which leads to a sharp decrease in heat intake (sunlight) on the ground surface and causes global temperatures to 1.5-2ºС.
The most ancient glaciation - Proteroza (2300-2000 million years ago) on the territory of South Africa, North America, Western Australia. In Canada, 12 km of sedimentary breeds were postponed, in which three powerful strata of glacial origin are distinguished.
Installed ancient glaciations (Fig. 23):
on the border of Cambrian-Proterozoy (about 600 million years ago);
late Ordovik (about 400 million years ago);
perm and coal periods (about 300 million years ago).
The duration of the glacial periods dozens - hundreds of thousands of years.
Fig. 23. Geochronological scale of geological eras and ancient glaciation
During the maximum spread of quaternary glaciation, the glaciers covered over 40 million km 2 - about a quarter of the entire surface of the continents. The largest in the Northern Hemisphere was the North American Ice Shield, which thoroughly reaching 3.5 km. Under the glacial cover up to 2.5 km, the entire Northern Europe was. Having achieved the greatest development of 250 thousand years ago, the Quaternary Glaciers of the Northern Hemisphere began to decline gradually.
Before the non -ogenic period throughout the land - a flat warm climate - in the area of \u200b\u200bthe islands of Spitsberena and the Land of Franz Joseph (on the paleobotanic finds of subtropical plants) at that time were subtropics.
Causes of climate cooling:
the formation of mountain ranges (Cordillera, Andes), isolated the area of \u200b\u200bthe Arctic from warm currents and winds (lifting the mountains per 1 km - cooling 6ºС);
creating a cold microclimate in the Arctic area;
termination of heat admission to the Arctic Area from Warm Equatorial Regions.
By the end of the non -ogenic period, North and South America were connected, which created obstacles to the free flow of ocean water, as a result:
equatorial waters turned for north;
warm waters of Golf Stream, sharply cooled in the northern waters, created a steam effect;
the loss of a large amount of precipitation in the form of rain and snow has sharply increased;
the decrease in temperature by 5-6ºС led to the glaciation of huge territories (North America, Europe);
a new period of glaciation began with a duration of about 300 thousand years (the frequency of the ilestone periods from the end of the neogen in anthropogen (4 glaciations) was 100 thousand years old).
The glaciation was not continuous throughout the quaternary period. There are geological, paleobotanic and other evidence that during this time the glaciers have completely disappeared at least three times, replacing the epochs of interdictions when the climate was warmer modern. However, the change of this warm epochs came cooling, and the glaciers applied again. Currently, the Earth is located at the end of the fourth era of quaternary glaciation, and, according to geological forecasts, our descendants in a few hundred thousand years will again be in the conditions of a glacial period, not warming.
On another way, the Quaternary glaciation of Antarctica developed. It arose for many millions of years before the time the glaciers appeared in North America and Europe. In addition to climatic conditions, this contributed to the high mainland existed here. Unlike the ancient glacial coverings of the northern hemisphere, which they disappeared, then again arose, the Antarctic Ice Cover changed little in its sizes. The maximum flying of Antarctica was more modern just a half times in volume and slightly more in the area.
The culmination of the last glacial era on Earth was 21-17 thousand years ago (Fig. 24), when the volume of ice increased approximately 100 million km 3. In Antarctic, the olelion at that time was captured by the entire continental shelf. The volume of ice in glacial cover seems to reach 40 million km 3, that is, it was about 40% more than its modern volume. The border of the packing ice shifted to the north of approximately 10 °. In the northern hemisphere 20 thousand years ago, a giant panarctic pedestrian cover was formed, uniting Eurasian, Greenland, Lavrentinsky and a number of smaller shields, as well as extensive floating shelves. The total shield volume exceeded 50 million km 3, and the level of the world ocean dropped at least 125m.
The degradation of Panarctic Pokrov began 17 thousand years ago from the destruction of the shelf glaciers. After that, the "maritime" parts of the Eurasian and North American Iceprokes, which have lost stability, began to colastically collapse. The collapse of glaciation occurred in just a few thousand years (Fig. 25).
A huge masses of water flowed from the edge of the glacial coverings at that time, gigantic sodium lakes arose, and their breakthroughs were many times more modern. Nature dominated natural processes, immeasurably more active than now. This led to a significant renewal of the natural environment, a partial change of animal and plant world, the beginning of the domination on the Earth of man.
The last recession of glaciers, which began over 14 thousand years ago, remains in memory of people. Apparently, it is the process of melting glaciers and lifting water levels in the ocean with an extensive flooding of the territories described in the Bible as a global flood.
12 thousand years ago, Holocene came - a modern geological era. The air temperature in moderate latitudes increased by 6 ° compared to the cold late Pleistocene. The glaciation took modern sizes.
In the historical era - about 3 thousand years - the advancing of glaciers occurred in separate centuries with a reduced air temperature and increased moisturgencies and got the name of small glacial periods. The same conditions were in the last century past era and in the middle of the past millennium. About 2.5 thousand years ago, a significant cooling climate began. The Arctic Islands were covered with glaciers, in the countries of the Mediterranean and the Black Sea region on the verge of a new era climate was colder and wet than now. In the Alps in the I millennium BC. e. The glaciers have moved to lower levels, closed the mountains of the ice and destroyed some highly located villages. This era accounts for the major advancing of Caucasian glaciers.
The climate at the turn of the I and II Millenniums of the New Era was completely different. Warm conditions and lack of ice in the northern seas allowed northern Europe's navigators to penetrate far from the north. Since 870, Iceland's colonization began, where glaciers at that time were less than now.
In the 10th century, Normans, Lelin-driven by Eyric, found the southern tip of the huge island, whose shores threw a thick grass and a high shrub, they founded here the first European colony, and the land was called Greenland, or the Green Earth (which now in no way You will say about the harsh lands of modern Greenland).
By the end of the first Millennium, the mountain glaciers in the Alps, in the Caucasus, in Scandinavia and Iceland, were strongly retreated.
The climate began to seriously change in the XIV century. Greenland began to advance, the summer thawing of the soils became more and more short-term, and by the end of the century, the eternal permafrost was firmly installed. The Arcticity of the Northern Seas increased, and attempts made in the next century to achieve Greenland in the usual way ended in failure.
Since the end of the 15th century, the advancing of glaciers began in many mountainous countries and polar areas. After a relatively warm XVI century, harsh centuries came, called a small glacial period. In the south of Europe, harsh and long and long winter were often repeated, in 1621 and 1669, the Bosphorus shed, and in 1709 the Adriatic Sea frowned along the shores.
IN 
a small glacial period ended about the second half of the XIX century and a relatively warm era, ongoing and understood, began.
Fig. 24. The boundaries of the last glaciation
Fig. 25. Scheme of the formation and melting of the glacier (according to the Northern Arctic Ocean profile - Kola Peninsula - Russian platform)
12,000 years ago ended the last ice age. In the very stern period, the glaciation threatened to man with extinction. However, after the departure of the glacier, he not only survived, but also created a civilization.
Glaciers in the history of the earth
The last glacier era in the history of the Earth is Cenozoic. It began 65 million years ago and continues until now. A modern man was lucky: he lives in a password, in one of the warmest periods of the planet's life. Far behind the most severe glacier era - Late Proterozoic.
Despite global warming, scientists predict the offensive of a new ice age. And if the real will come only through the millennium, then a small glacial period, which for 2-3 degrees will reduce the annual temperatures, may come quite soon.
The glacier became a real test of a person, forcing him to invent funds for his survival.
Last glacial period
Vurm or Vistula oleloenion began approximately 110,000 years ago and ended in the tenth of the millennium BC. Peak cold weather came for a period of 26-20 thousand years ago, the final stage of the Stone Age, when the glacier was the greatest.
Small glacial periods
Even after the glaciers melted, the story knew the periods of noticeable cooling and warming. Or, in a different way, - climatic pessimums and optimum. Pessimums are sometimes called small glacial periods. In the XIV-XIX centuries, for example, a small glacial period occurred, and at the time of the great relocation of peoples there was a random-medieval pessimum.
Hunting and meat food
There is a view, according to which the ancestor of man was rather a padelver, since he could not spontaneously take a higher ecological niche. And all the well-known tools of labor served to cut the remains of animals that were selected from predators. However, the question of when and why a person began to hunt still causes discussions.
In any case, thanks to the hunting and meat food, an ancient man received a large stock of energy, which allowed him to make it better to endure cold. The skins of the dead animals were used as clothes, shoes and housing walls, which increased the chances to survive in the harsh climate.
Strying
Millions appeared straight years ago, and his role was much more important than in the life of a modern office worker. After freeing his hands, a person could do intense the construction of the dwelling, the production of clothing, processing of workers, the prey and the preservation of fire. Self-free ancestors are fluent in open areas, and their lives no longer depended on the collection of fruits of tropical trees. Already millions of years ago, they moved freely over long distances and mined food in river runoff.
Stirry played a cunning role, but it was still more advantage. Yes, the man himself came to the cold regions and adapted to life in them, but at the same time could find both artificial and natural shelters from the glacier.
the fire
The fire in the life of an ancient man was originally an unpleasant surprise, not a good. Despite this, the ancestor of man first learned to "extinguish" him, and later to use for his own purposes. Traces of use of fire are found in parking, which are 1.5 million years old. This allowed to improve meals by cooking protein food, as well as maintain activity at night. This additionally increased the time to create survival conditions.
Climate
The Cenozoic Glacier Era was not a solid glaciation. Every 40 thousand years in the ancestors of people had the right to the "respite" - temporary thaws. At this time, the glacier retreat, and the climate became softer. During periods of harsh climate, natural asylum were caves or rich flora and fauna regions. For example, the south of France and the Pyrenean Peninsula served as a refuge of many early crops.
The Persian bay of 20,000 years ago was a rich forest valley and herbal vegetation, truly "doping" landscape. There were wide rivers that are superior to the sizes of Tiger and Effrata one and a half times. Sahara in certain periods became a wet savanna. The last time this happened 9000 years ago. Confirmation of this can serve as the rock paintings on which the abundance of animals is depicted.
Fauna
Huge ice mammals, such as bison, woolly rhino and mammoth, have become an important and unique source of food of ancient people. Hunting for such large animals demanded great coordination of effort and noticeably rallied people. The effectiveness of "collective work" has once again showed itself in the construction of parking lots and clothing. Deer and wild horses in the ancient people used no less "honor."
Language and communication
Language was perhaps the main life of an ancient person. It is due to the speech that important technologies for processing guns, mining and maintenance of fire were preserved and passed from generation to generation, as well as various human adaptations for everyday survival. Perhaps the Paleolithic language discussed the details of hunting on large animals and migration directions.
Allend warming
Until now, scholars argue: whether the extinction of mammoths and other glacial animals did the man's hands or caused by natural causes - the allend warming and disappearance of the forage base plants. As a result of the extermination of a large number of animal species, a person in harsh conditions threatened death from lack of food. Cases of death of whole cultures are known simultaneously with the extinction of mammoths (for example, Culture of Klovis in North America). However, warming has become an important factor in resettlement of people in the regions whose climate has become suitable for the origin of agriculture.
Despite the fact that it may be difficult to understand, our planet is constantly changing. The continents are constantly shifted and faced with each other. Volcanoes are eructed, glaciers are expanding and retreating, and life should keep up with all these occurrence changes.
Throughout its existence in different periods that lasted millions of years, the Earth was covered with a kilometer polar ice shield and mountain glaciers. The theme of this list will be glacial periods characterized by very cold climatic conditions and the presence of ice extending so far as the eye can see.
10. What is the Ice Age?
Want to believe, you want, no, but the definition of the ice age is not so definitely, as some might think. Of course, we can characterize it as a period when global temperatures were much lower than today, and when both hemispheres are covered with a thickness of ice stretching for thousands of miles to the equator.
However, the problem with this definition is that it describes any glacial period from today's point of view and does not actually take into account the entire planetary history. Who can say that today we do not live in conditions of lower temperatures than the average? In this case, we are actually in the glacial period right now. Only some scientists who devoted their lives to the study of such phenomena can confirm this. Yes, we actually live in the glacial period, and we will be convinced of this in a minute.
The best definition of the glacial period would be that this is a long period of time when the atmosphere and the surface of the planet have a low temperature, which leads to the presence of polar ice shields and mountain glaciers. This can continue several million years, during which there are also periods of glaciation, characterized by the ice cover and the growth of glaciers on the surface of the planet, as well as interledstial periods - intervals lasting several thousand years, when the ice retreats, and becomes warmer. In other words, what we know as the "last ice age" is, in fact, one of these stages of glaciation, part of a larger glacial period of Pleistocene, and at present we are in a member period known as Golotocene, which has begun around 11 700 years ago.
9. What causes the glacial period?
At first glance, the ice age is similar to some global warming in the opposite direction. This is to a certain extent, but there are several other factors that can initiate and promote the beginning of the ice age. It is important to note that the study of the glacial periods began not so long ago, and our understanding of this process is not yet complete. Nevertheless, there is some scientific consensus in several factors that contribute to the beginning of the ice age.
One of these obvious factors is the level of greenhouse gases in the atmosphere. There is evidence that the concentration of these gases is growing in the air and decreases together with the retreat and increasing ice shields. But some argue that these gases do not necessarily launch each glacial period and affect only its severity.
Another key factor playing an important role is tectonic plates. Geological entries indicate a correlation between the position of the continents and the beginning of the ice age. This means that in a certain position, the continents may interfere with the so-called global ocean conveyor - a global flow system that carry cold water from the poles to the equator and vice versa.
Continents can also be directly at the top of the pole as Antarctic today, or lead to the fact that the polar reservoirs will be completely or partially surrounded by land as the Arctic Ocean. Both of these factors contribute to ice formation. Continents can also be collected around the equator, blocking ocean flows, which leads to the glacial period.
That is how it happened during the cryogenic period, when the supercontinent of the birthplace covered most of the equator. Some experts even say that Himalayas played an important role in the current glacier period. After these mountains began to form about 70 million years ago, they contributed to the increase in precipitation on the planet, which, in turn, led to a steady decrease in CO2 in the air.
Finally, we have orbits for which the Earth is moving. It also partially explains the periods of glaciation and interlegone periods during any particular glacial period. It is experiencing a number of periodic changes during a circular movement around the Sun, which are called Milankovich cycles (Milankovitch Cycles). The first of these cycles is the Earth's eccentricity, which is characterized by the form of the orbit of our planet around the Sun.
Every 100,000 years or near the orbit of the Earth becomes more or less similar to the ellipse, this means that it will get more or less sunlight. The second of these cycles is the tilt of the axis of the planet, which is on average changing several degrees every 41,000 years. This slope affects the seasons on the ground and the difference in solar radiation, obtained by poles and equator. Thirdly, we have a precession of the Earth, which is expressed by oscillation when the Earth revolves around his. This happens approximately every 23,000 years and leads to the fact that winter in the northern hemisphere will occur when the Earth will be further from the Sun, and the summer - when it is closest to the sun. If this happens, the difference in the degree of severity between the seasons will be more than today. In addition to these major factors, we can also sometimes suffer from a lack of spots in the sun, shocks of large meteorites, the strongest eruptions of volcanoes or nuclear wars, which among other things can potentially lead to the beginning of the ice age.
8. Why do they continue so long?
We know that the glacial periods usually last millions of years. The reason for this can be explained by a phenomenon known as albedo. This is the reflectivity of the earth's surface when it comes to the shortwave radiation of the Sun. In other words, the greater the surface of our planet is covered with white ice and snow, the more solar radiation is reflected back into space, and the colder becomes on Earth. This leads to the appearance of even more ice and even greater reflective ability in the cycle of positive feedback, which lasts millions of years. This is one of the reasons why it is so important that the Ice of Greenland remains where it is. Because if this does not happen, the reflectivity of the island will decrease, which will lead to an increase in global temperature.
However, the glacial periods end up, as well as their glaciation periods. As the air becomes colder, it can no longer hold so much moisture, as before, which leads, in turn, to fall out a smaller amount of snow and the impossibility of expanding ice hats and even their maintenance. As a result, the negative feedback cycle begins, which marks the beginning of the interleden period.
According to this logic in 1956, the theory was proposed, assumed that the northern ice ocean, not covered with ice, would cause more snowfall at higher latitudes, above and below the polar circle. This snow may be so much that it does not melt during the summer months, increasing the albedo of the Earth and reducing the total temperature. Over time, this will allow you to form ice on lower latitudes and in medium latitudes - push, triggering the detergent process.
7. But how do we find out what the Ice Age was really?
The reason why people began to think about glacial periods, became, first of all, some huge boulders, which were in the center of an empty area without any explanation as to how they got there. The study of the processes of glaciation began in the middle of the 18th century, when the Swiss engineer and Geographer Pierre Martel began to document randomly scattered mountain formations within the Alpine Valley and below the glacier. Local residents told him that these huge boulders pushed the glacier, who once stretched much further in Mount.
For decades, other similar cases have been documented all over the world, which has become the basis for the theory of glacial periods. Since then, other forms of evidence were also taken into account. Geological features, including previously mentioned rocks containing glacial sediments, carved valleys, such as fjords, glacial lakes and various other forms of the edged surface of the Earth. The problem with them is that they are difficult to dates, and subsequent glaciations can distort or even completely erase previous geological formations.
More accurate data comes with paleontology - the study of fossils. Although not without some of the shortcomings and inaccuracies, but Paleontology speaks of the history of the glacial periods, showing us the distribution of organisms adapted to cold, once having lived on lower latitudes, and organisms that usually flourish in a warmer climate, the number of which either decreased Closer to the equator, or they completely disappeared.
However, the most accurate proofs give isotopes. Differences in the ratios of isotopes between fossil, sedimentary rocks and ocean sediments can tell a lot about the environment in which they were formed. Speaking about the current glacier period, we also have access to the ice nuclei obtained from Antarctica and Greenland, which are the most reliable form of evidence today. When formulating their theories and forecasts, scientists rely on their combination where possible.
6. Large glacial periods
At the moment, scientists are confident that there were five large glacial periods during the long history of the Earth. The first of them, known as the Huronian glaciation, occurred about 2.4 billion years ago and lasted about 300 million years, is considered the longest. The cryogenic glacial period occurred about 720 million years ago and lasted to 630 million years ago. This period is considered the most severe. The third massive glaciation occurred about 450 million years ago and continued about 30 million years. It is known as the Ando-Sugar Ice Age and caused the second largest mass extinction in the history of the Earth after the so-called great extinction. For 100 million years, the ice age of the car occurred between 360 and 260 million years ago and was caused by the appearance of terrestrial plants, the remains of which we now use as fossil fuels.
Finally, we have a Pleistocene Ice Age, also known as a Pliocene-Quaternary glaciation. It began approximately 2.58 million years ago, and since then several periods of glaciation and flight periods have passed with a difference from about 40,000 to 100,000 years. However, over the past 250,000 years, the climate changed more often and sharply, and the previous interlegone period was interrupted by numerous cold periods, which continued for several centuries. The current interlegone period, which began about 11,000 years ago, is atypical due to a relatively stable climate, which was up to this point. It is safe to say that people would not be able to carry out agriculture and achieve the current level of civilization if it were not for this unusual temperature stability.
5. Witchcraft
"I'm sorry, what?" We know what you thought when I saw this title on our list. But now we will explain everything ...
For several centuries, starting from about 1300 and ending in about 1850, the world survived the period known as the Small Ice Age. In order for the global temperature to decrease, especially in the northern hemisphere, as a result of which mountain glaciers rose, the rivers were frozen, and the crop died, several factors took. In the middle of the 17th century, several villages were completely destroyed in Switzerland because of the invaded glaciers, and in 1622, even the southern part of the Bosphorus Strait around Istanbul completely froze. In 1645, the situation worsened and continued for the next 75 years, during a period known to scientists today at least Mount.
During this time, there was little solar spots in the sun. These stains are areas on the surface of the Sun, the temperature in which is significantly lower. They are caused by the concentration of magnetic streams in our star. These spots themselves are likely to contribute to a decrease in the temperature of the Earth, but they are surrounded by very bright areas, known as the facals. The farm has a significantly higher radiation power, which is much superior to the weakness of the glow caused by sunny stains. Thus, the sun without stains actually has a lower level of radiation than usual. It is estimated that during the 17th century, the Sun pulled by 0.2 percent, which partly explains this small glacial period. During this time, more than 17 volcanic eruptions occurred in the world, which even more weakened the sun's rays.
Economic adversity caused by this centuries-old cold period had an incredible psychological impact on people. Frequent loss of crops and shortage of firewood led to the fact that in Salem, Massachusetts, there were serious cases of mass hysteria. In the winter of 1692, twenty people, fourteen of which were women, were hanged on charges that were witches and to blame for all adversity of the rest. Five others, two of whom were children, later died in prison, where they were placed on the same charges. Due to adverse weather in places such as Africa, even today, people sometimes accuse each other in the fact that they are witches.
4. Earth - Snowball
The first glacial period on Earth was also the longest. As we mentioned earlier, it continued as much as 300 million years. Known as a Guronian glaciation, this incredibly long and cold period began about 2.4 billion years ago, while only single-cell organisms existed on Earth. The landscape looked quite different than today, even before the ice fed everything around. However, a number of events occurred, which ultimately led to the apocalyptic event of global scale, as a result of which most of the planet turned out to be covered with thick ice. Anaobic organisms prevailed to the Guronian glaciation on Earth, which did not need oxygen. Oxygen was essentially poisonous for them and an extremely rare element in the air, it was only 0.02% of the atmosphere. But at some point another form of life originated - cyanobacteria.
This tiny bacterium was the first one who had ever used photosynthesis as a way of nutrition. By the on-product of this process is oxygen. As these tiny creatures flourished in the World Ocean, they highlighted millions and millions of tons of oxygen, increasing its concentration in the atmosphere to 21% and provoking the disappearance of all anaerobic life. This event is called a great oxygen event. The air was also filled with methane, and in contact with oxygen it turned into CO2 and. However, methane is 25 times more efficient as greenhouse gas than CO2, which means that this transformation led to a decrease in global temperatures, which, in turn, launched the Guronian glaciation and the first mass extinction on Earth. Sometimes the volcanoes have added an additional CO2 into the air, which led to the interglacial periods.
3. Baked Alaska
If its title is not clear, the cryogenic glacial period was the coldest period in the long history of the Earth. Today, he is also the subject of many scientific disputes. One of the topics of discussion is the question of whether the land was completely covered with ice, or along the equator remained the open water line - the theory of a snowy ball or land - snow, as some call these two scenarios. The cryogenic period continued from about 720 to 635 million years ago and can be divided into two major events of glaciation, known as starting (720-680 million years) and Marinoan (approximately from 650 to 635 million years old). It is important to note that at that moment there was no multicellular life, and some believe that the scenario of the Earth - Snowball became a catalyst for its evolution during the so-called Cambrian explosion.
A particularly interesting study was published back in 2009, it was focused on, in particular, Marinoian glaciation. According to the analysis, the atmosphere of the Earth was relatively warm, and its surface was covered with a thick layer of ice. This is only possible if the planet is completely or almost completely covered with ice. This phenomenon was compared with the dessert baked Alaska, where ice cream does not melt immediately after it was placed in the oven. It turns out that there were many greenhouse gases in the atmosphere, but contrary to expectations, it was not prevented and was not related to the Ice period. These gases were present in such large quantities due to increased volcanic activity that followed the collapse of the supercontinent of the birthplace. It is believed that this long-term volcanic activity helped "launch" the ice age.
However, the scientific community warns that something like this may repeat if the atmosphere begins to reflect too much sunlight into space. One of these periods can be launched by a mass eruption of volcanoes, nuclear war or our future attempts to mitigate the effects of global warming, spraying too many sulphate aerosols into the atmosphere.
2. Flood myths
When about 14,500 years ago, ice glaciers began to melt, the water did not flow into the ocean equally throughout the land. In some places, such as North America, huge ice lakes began to form. These lakes appear as a result of the fact that on the way of water there is an obstacle in the form of an ice wall or glacial sediments. For 1600 years, Lake Agassis (Lake AGASSIZ) covered an area of \u200b\u200b440,000 square meters. km more than any lake existing today. It was formed in the territory of North Dakota, Minnesota, Manitoba, Saskatchewan and Ontario. When the dam, finally, broke out, fresh water joined the Northern Arctic Ocean through the Mackenzie River River Valley.
This high influx of fresh water weakened the oceanic flow of 30%, immersing the planet in the 1200-year period of glaciation, known as early drias. It is assumed that this unlucky turn of events led to the destruction of cloves of Klovis and North American megafauna. Records also show that this cold period unexpectedly ended about 11,500 years ago, and the temperature in Greenland rose to -7 degrees Celsius in just ten years.
During the early drias, the ice glaciers were replenished, and when the planet began to warm up again, lake Agassis appeared. However, this time it has connected with the same large lake, known as Ojibway. Soon after their merger, a new breakthrough occurred, but this time in the Hudson Bay. Another cold period that occurred 8,200 years ago is known as an event 8.2 Kilaeear (8.2 Kiloyear Event).
Although low temperatures were held only 150 years, this event made it possible to increase the sea level of 4 meters. Interestingly, historians were able to link the origins of many myths about floods from around the world with this period of time. This sudden increase in sea level also led to the fact that the Mediterranean Sea paved his way through the Bosphorus Strait and flooded the Black Sea, which at that time was only freshwater lake.
1. Martian Ice Age
Unable to our control glacial periods are natural phenomena that happens not only on Earth. Like our planet, Mars also have periodic changes in orbit and an axis slope. But unlike the Earth, where the ice age implies the growth of polar ice hats, other processes occur on Mars. Since its axis is inclined more than the land axis, and the poles get more sunlight, the Martian ice age means that the polar ice caps are actually retreating, and the glaciers on average latitude are expanding. This process stops in the interglacial periods.
Over the past 370,000 years, Mars slowly went out of his glacial period and entered into the interglacial period. According to scientists estimates, approximately 87,115 cubic kilometers of ice accumulates on the poles, most accumulates in the northern hemisphere. Computer models also showed that Mars can be completely covered with ice during glaciation. However, these studies are in the early stages, and, given the fact that we are still far from a complete understanding of our own glacial periods on Earth, we cannot expect that we will find out everything that happens on Mars. Nevertheless, this study may be useful, given our plans for the future for the Red Planet. It also helps us very much on Earth. "Mars serves as a simplified laboratory for testing climate models and scenarios, without oceans and biology, which we can then use for a better understanding of earthly systems," said the planetary scientist Isaac Smith (ISAAC Smith).
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 so cold times that glaciation achieved those regions that are currently related to moderate zones. Most likely, the change of these periods was cyclical. At warm times, ice could be relatively small, and it was only in the polar regions or on the tops of the mountains. An important feature of the glacial periods is that they change the nature of the earth's surface: each glaciation affects the appearance of the Earth. By themselves, these changes may be small and insignificant, but they are constant.
History of glacial periods
We do not know exactly how many glacial periods were throughout the history of the Earth. We know at least five, perhaps seven glacial periods, starting with Precambriansky, in particular: 700 million years ago, 450 million years ago (Ordovica period), 300 million years ago - Permo-carboxyloy, one of the largest glacial periods, affected southern continents. Under the south continents, the so-called Gondwana is meant - an ancient supercontinent, which included Antarctica, Australia, South America, India and Africa.
The most recent glaciation refers to the period in which we live. The Quaternary period of the Cenozoic era began about 2.5 million years ago, when the northern hemispheric glaciers reached the sea. But the first signs of this glaciation date back to 50 million years ago in Antarctica.
The structure of each glacial period is periodic: there are relatively short warm epochs, and there are longer periods of icing. Naturally, cold periods are not a consequence of glaciation alone. The glaciation is the most visual consequence of cold periods. However, there are quite long intervals that are very cold, despite the lack of glaciation. Today, examples of such regions are Alaska or Siberia, where it is very cold in winter, but there is no glaciation, since there is not enough precipitation capable of providing a sufficient amount of water to form glaciers.
Opening of glacial periods
It is known from the middle of the XIX century on Earth. Among the many names associated with the discovery of this phenomenon, the first is usually called the name of Louis Agassis, a Swiss geologist who lived in the middle of the XIX century. He studied the Alps glaciers and realized that once they were much more extensive than today. It noticed not only he. In particular, Jean de Charpete, another Swiss, also noted this fact.
It is not surprising that these discoveries were made mainly in Switzerland, since the glaciers still exist in the Alps, even though they are fast enough. It is easy to see that once the glaciers were much more - just look at the Swiss landscape, the triggers (Ice Valleys) and so on. However, it was Agassis first that he put forward this theory in 1840, posing it in the book "Étude Sur Les Glaciers", and later, in 1844, he developed this idea in the book "Système Glaciare". Despite the initial skepticism, over time, people began to understand that it is really true.
With the advent of geological mapping, especially in Northern Europe, it became clear that earlier the glaciers had a huge scale. Then there were extensive discussions on how this information correlates with the World Floral, because the conflict arose between the geological evidence and biblical teachings. Initially, glacial deposits were called deluel, because they were considered evidence of a worldwide flood. Only then it became known that such an explanation does not fit: these deposits were proof of cold climate and extensive glaciation. By the beginning of the twentieth century it became clear that the glaciation was many, and not one, and from the moment this region of science began to develop.
Studies of glacial periods
Known geological confirmation of glacial periods. The main evidence of glaciation occurs from characteristic deposits formed by the glaciers. They persist in a geological cut in the shape of thick ordered layers of special injuries (sediments) - diamine. These are simply ice accumulations, but they include not only the deposition of the glacier, but also the malcasses formed by its flows, glacial lakes or glaciers moving towards the sea.
There are several forms of glacial lakes. Their main difference lies in the fact that they are aquatic body fenced with ice. For example, if we have a glacier who rises to the valley of the river, then it blocks the valley as a plug in a bottle. Naturally, when the ice blocks the valley, the river will still flow, and the water level will increase until it flows across the edges. Thus, the glacial lake is formed through direct contact with ice. There are certain deposits that are contained in such lakes and which we can reveal.
Due to how the glaciers are melted, which depends on seasonal changes in temperature, the annual yield occurs. This leads to the annual increase in minor deposits falling from ice into the lake. If we then look at the lake, we will see there lamps (rhythmic layered precipitation), which are also known under the Swedish name "Verva" ( varve.) What does "annual accumulations" mean. Thus, we can really see the annual lamination in glacial lakes. We can even count these preventive and find out how long this lake existed. In general, with this material, we can get a lot of information.
In Antarctica, we can see the huge size of the shelf glaciers who go out of the ground in the sea. And naturally, ice float, so it keeps on the water. As he floats, he carries with him pebbles and minor deposits. Because of the thermal exposure to water, ice melts and resets this material. This leads to the formation of the process of so-called rafting rocks that go into the ocean. When we see fossil sediments of this period, we can find out where there was a glacier, how far he stretched and so on.
Causes of glaciation
The researchers believe that the glacial periods arise because the land climate depends on the uneven warm-up of its surface of the sun. For example, the equatorial regions, where the sun is almost vertically above the head, are the warmest zones, and the polar regions, where it is at a large angle to the surface, the coolest. 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 was an ordinary ball, this transfer would be very effective, and the contrast between the equator and the poles is very small. So it was in the past. But since now there are continents, they become on the path of this circulation, and its streams becomes very complex. Simple streams are constrained and changed - largely due to the mountains, which leads to the circulation schemes that we see today and which are managed by trade winds and oceanic currents. For example, one of theories about why the Ice Age began 2.5 million years ago, binds this phenomenon with the emergence of the Himalayan mountains. Himalayas are still growing very quickly, and it turns out that the existence of these mountains in a very warm part of the Earth manages such things as the monsoon system. The beginning of the Quaternary Ice Age is also associated with the closure of the Panama Isthmus, which connects the north and south of America, which prevented the transfer of heat from the Equatorial Pacific Zone to the Atlantic.
If the location of the continents relative to each other and relative to the equator allowed the circulation to work effectively, it would be warm on the poles, and relatively warm conditions would be preserved throughout the earth's surface. The amount of heat obtained by the Earth would be constantly and only varied a bit. But since our continents create serious corporate barriers between the North and South, we have pronounced climatic zones. This means that the pole is relatively cold, and the equatorial regions are warm. When everything happens as now, the earth may vary under the influence of variations in the amount of solar heat that it gets.
These variations are almost completely constant. The reason for this is that over time the earth's axis changes, as the earth orbit changes. Taking into account such complex climatic zoning, the change in the orbit may contribute to long-term changes in the climate, which leads to climate fluctuations. Because of this, we have no solid icing, and periods of icing interrupted by warm periods. This happens under the influence of orbital changes. Recent orbital changes are treated as three separate phenomena: one 20 thousand years long, the second is 40 thousand years old, and the third is 100 thousand years.
This led to deviations in the circuit of cyclic climate change during the ice age. The icing, most likely, arose during this cyclical period of 100 thousand years. The last intersection era, which was the same warm as the current, lasted about 125 thousand years, and then there was a long glacier epoch, which took about 100 thousand years. Now we live in another interglacial era. This period will not last forever, so the next glacier era is waiting for us in the future.
Why the glacial periods are completed
Orbital changes change the climate, and it turns out that the glacial periods are characterized by alternating cold periods that can last up to 100 thousand years, and warm periods. We call them glacial (glyhal) and interglacial (interpretor) by epochs. The interledstial era is usually characterized by approximately the conditions that we see today: high sea levels, limited objects of icing and so on. Naturally, and now there are glaciation in Antarctica, Greenland and other similar places. But in general, climatic conditions are relatively warm. In this, the essence of the interviewology: high sea level, warm temperature conditions and the generally smooth climate as a whole.
But during the Ice Epoch, the average annual temperature varies significantly, the vegetative belts are forced to shift to the north or south depending on the hemisphere. Regions like Moscow or Cambridge become uninhabited, at least in winter. Although they can be inhabited in summer because of a very pronounced contrast between the seasons. But what actually happens: cold zones are significantly expanding, the average annual temperature is reduced, and general climatic conditions become very cold. While the greatest glacial events are relatively limited in time (perhaps about 10 thousand years), the entire long cold period can last 100 thousand years or even more. This looks like an interledeter cyclicity.
Due to the duration of each period, it is difficult to say when we leave the current era. This is due to the tactonics of the plates, the location of the continents on the surface of the Earth. Currently, the North Pole and the South Pole are isolated: Antarctic is located on the South Pole, and the Arctic Ocean in the north. Because of this, there is a problem with heat circulation. Until the location of the continents change, this ice age will continue. In accordance with long-term tectonic changes, it can be assumed that it will take another 50 million years in the future until significant changes occur, which will allow land to leave the glacial period.
Geological consequences
Of course, the main consequence of the glacial period is huge glacial shields. Where does the water come from? Of course, from the oceans. What happens during the glacial periods? Glaciers are formed as a result of precipitation on land. Due to the fact that the water does not return to the ocean, the sea level falls. In the times of the strongest glaciation, the sea level may fall more than one hundred meters.
It releases the huge sections of the continental shelf, which today are flooded. 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 Bering Strait, connecting Alaska with Eastern Siberia. It is fine enough, about 40 meters, so if the sea level drops to one 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 the regions where today they cannot get. Thus, the colonization of North America depends on the so-called berygia.
Animals and glacial
It is important to remember that we ourselves are "products" of the glacial period: we evolved during it, so we can survive it. However, it's not a matter of individual individuals - this is a matter of the whole population. The problem today is that we are too much and our activity has significantly changed natural conditions. In natural conditions, many animals and plants we see today have a long story and perfectly experience the ice age, although there are those that evolve insignificantly. They migrate, adapt. There are zones in which animals and plants survived the ice age. These so-called refugiums were located on the north or south of their place today.
But as a result of human activity, some of the species died or extinct. It happened on all continents, it is possible, with the exception of Africa. A huge number of large vertebrates, namely mammals, as well as the silent in Australia, was exterminated by a person. This was caused either directly by our activities, such as hunting, or indirectly - the destruction of their habitat. Animals living in northern latitudes today, in the past lived in the Mediterranean. We destroyed this region so much that these animals and plants will most likely be very difficult to colonize it again.
The consequences of global warming
Under normal conditions, on geological standards, we would soon be returned to the glacial period. But due to global warming, which is the consequence of human activity, we displays it. We will not be able to prevent it at all, since the reasons that caused him in the past exist now. Human activity, unintended nature element, affects atmospheric warming, which may already cause a delay in the next glant.
Today, climate change is a very relevant and exciting issue. If the Greenland ice shield melts, the sea level will rise six meters. In the past, during the previous intergarent era, which was about 125 thousand years ago, the Greenland ice shield richly melted, and the sea level was 4-6 meters above today. This, of course, is not the end of the world, but not temporary complexity. In the end, the Earth was recovered from the catastrophe before, she will be able to survive this.
The long-term forecast for the planet is not bad, but for people this is another question. The more research we conduct research, the better we understand how the Earth changes and what it leads, the better we understand the planet on which we live. This is important because people finally began to think about changing the level of sea, global warming and the influence of all these things on agriculture and the population. Much of this is associated with the study of the glacial periods. With the help of these studies, we recognize the mechanisms of glaciation, and we can use this knowledge with the absorption, trying to soften some of these changes that they themselves call. This is one of the main results and one of the objectives of the study of the glacial periods.
This is the transfer of the article of our English-language publication Serious Science. You can read the original version of the text by reference.
Russian scientists promise that in 2014 the Ice Age will begin in the world. Vladimir Bashkin, Head of the Gazprom VNIIGAZ laboratory, and Rauf Galiullin, an employee of the Institute of Fundamental Problems of Biology of the Russian Academy of Sciences, argue that global warming will not be. According to scientists, warm winters are a consequence of the cyclic activity of the Sun and cyclic climate change. This warming continued from the 18th century to the present, and from the next year the cooling will begin on Earth.
The small glacial period will step up gradually and will last at least two centuries. His peak decrease in temperature will reach the middle of the 21st century.
At the same time, scientists say that an anthropogenic factor is the influence of a person on the ecology - does not play in the change of climate of such a big role as it is customary. The case in marketing, they consider Bashkin and Galiullin, and the promise of cold weather every year is only a way to overestimate the price of fuel.
Pandora drawer is a small glacial period in the 21st century.
In the next 20-50 years, we face a small glacial period, because it was already before and should come again. The researchers believe that the onset of the small glacial period was associated with the slowdown in the course of the Gulf Stream of about 1300. In the 1310s, Western Europe, judging by the annals, survived a real environmental catastrophe. According to the French "Chronicle of Matthew Parisian", after the traditionally warm summer of 1311 followed four frown and rainy summer 1312-1315. Strong rains and unusually severe winters led to the death of several yields and freezing fruit gardens in England, Scotland, Northern France and Germany. In Scotland and Northern Germany, viticulture and wine production ceased. Winter frosts began to hit even northern Italy. F. Petrarka and J. Bokacho fixed that in the XIV century. Snow often fell out in Italy. The direct consequence of the first phase of the MLP was massive hunger of the first half of the XIV century. Indirect - crisis of feudal farming, renewal of the barbecue and large peasant uprisings in Western Europe. In the Russian lands, the first phase of MLP made itself felt in the form of a turn of the "rainy years" of the XIV century.
Approximately from the 1370s, the temperature in Western Europe began to slowly increase, mass hunger and crocheas stopped. However, the cold, rainy summer were frequent phenomenon throughout the XV century. In winter, snowfall and freezing in the south of Europe were often observed. Relative warming began only in the 1440s, and it immediately led to an increase in agriculture. However, the temperatures of the preceding climate optimum were not restored. For Western and Central Europe, snowy winter has become a common phenomenon, and the period of "Golden Autumn" began in September.
What does it affect climate? It turns out the sun! Back in the XVIII century, when quite powerful telescopes appeared, astronomers paid attention to the fact that the number of spots in the sun increases and decreases with certain frequency. This phenomenon was called solar activity cycles. They found out the average duration - 11 years (Cycle Schwab - Wolf). Later were open and longer cycles: a 22-year-old (Hale cycle), associated with the variability of the polarity of the solar magnetic field, the "age-old" cycle of Glaisisberg lasting about 80-90 years, as well as a 200-year-old (Züss cycle). It is assumed that there is even a cycle of 2400 years.
"The fact is that longer cycles, such as centuries, modulating the amplitude of the 11-year cycle, lead to the emergence of grand minima," said Yuri Nagovitsyn. There are several modern science: a few: the minimum of Wolf (the beginning of the XIV century), the minimum of the Schuperov (the second half of the XV century) and the minimum of mounder (the second half of the XVII century).
Scientists suggested: the end of the 23rd cycle, in all likelihood, coincides with the end of the century-old cycle of solar activity, the maximum of which was in 1957. This, in particular, also shows the curve of the relative numbers of Wolf, approaching the minimum mark in recent years. An indirect evidence of the superposition is and tightening the 11-year-old. Comparing the facts, scientists understood that, apparently, the combination of factors indicates an approaching grand minimum. Therefore, if in the 23rd cycle, the activity of the Sun amounted to about 120 relative Wolf numbers, then in the following it should be about 90-100 units, assume astrophysics. Next, the activity will decrease even stronger.
The fact is that longer cycles, for example, the age-old, modulating the amplitude of the 11-year cycle, lead to the occurrence of amplitude minima, the last of which occurred in the XIV century. What consequences are waiting for the earth? It turns out that it was during the graceful highs and minima of solar activity on Earth, large temperature anomalies were observed.
The climate is a very difficult thing, trace all its changes all the more globally is very difficult, but as scientists suggest, greenhouse gases that brings the life of humanity a little slowed down the arrival of a small glacial period, and the world ocean saccumulating part of the heat over the past decades does the same delaying process The beginning of a small glacial period, giving up a little bit warm. As it turned out later, vegetation on our planet is good absorbing the surplus of carbon dioxide (CO2) and methane (CH4). The main impact on the climate of our planet still has the sun, and we will not be able to do this.
Nothing catastrophic will certainly not happen, but the parts of the northern regions of Russia can be at all suitable for life, oil production in the north of the Russian Federation may stop at all.
In my opinion, the decrease in global temperature can already be expected in 2014-2015. In 2035-2045, solar luminosity will reach a minimum, and after this, with a lag for 15-20 years, the next climatic minimum will come - deep cooling of the land climate.
News about the end of the world "Earth threatens a new ice age.
Scientists predict a decrease in solar activity, which can occur over the next 10 years. The consequence of this may be the repetition of the so-called "small glacial period", which happened in the XVII century, writes Times.
According to the forecasts of scientists, the frequency of solar spots in the coming years can significantly decrease.
The cycle of the formation of new solar spots affecting the temperature of the Earth is 11 years. However, employees of the American National Observatory suggest that the next cycle can be very late or not to happen at all. According to the most optimistic forecasts, they say, the new cycle can begin in 2020-21 years.
Scientists are reflected by the change in solar activity to the second "minimum of the mound" - the period of a sharp decline in solar activity, which lasted 70 years, from 1645 to 1715. During this time, also known as the "Small Ice Age", the Thames River was covered with almost 30 meter ice, along which horse drives successfully moved from Whitehall to the London Bridge.
According to the predictions of the researchers, the decline in solar activity may lead to the fact that the average temperature on the planet will fall by 0.5 degrees. However, most scientists are confident that it is too early to beat the alarm. During the "small glacial period" in XVII, the air temperature fell significantly only in the north-west of Europe, and even then only 4 degrees. On the rest of the planet, the temperature fell only to half graduates.
The second coming of a small glacial period
At historical time, Europe has already experienced a long abnormal cooling.
Abnormally strong frosts who reigned in Europe at the end of January, almost led to a full-scale collapse in many Western countries. Many highways were blocked due to powerful snowfalls, the power supply was interrupted, the reception of airports at airports was abolished. Because of the frosts (in the Czech Republic, for example, those who have achieved -39 degrees) are canceled in schools, the work of exhibitions and conducting sports matches. Only in the first 10 days of extreme frosts in Europe killed more than 600 people.
For the first time in many years, frozen from the Black Sea to Vienna Danube (ice there reaches 15 cm thick), blocking hundreds of ships. To prevent the freezing of the Seine in Paris, a long-standing icebreaker was laid in Paris. The ice fed the canals of Venice and the Netherlands, skaters and cyclists ride in Amsterdam on its frozen water arteries.
The situation is extraordinary for modern Europe. However, looking at the well-known works of European art of the XVI-XVIII centuries or in the weather record of those years, we learn that the freezing of the channels in the Netherlands, the Venetian lagoon or the hay was for that time the phenomenon is quite frequent. Especially extreme was the end of the XVIII century.
So, 1788 I remember Russia and Ukraine "Great Winter", accompanied throughout their European part "Extraordinary staudes, storms and snow". In Western Europe in December of the same year, a record temperature of -37 degrees was recorded. Birds frozen on the fly. Venetian lagoon frozen, and throughout its length, the townspeople skated. In 1795, the ice was sowed to the banks of the Netherlands with such a force that a whole military squadron was in captivity, which was then surrounded by a French horse escade from Sushi. In Paris, in that year, frosts reached -23 degrees.
Paleoclimatologists (historians exploring climate change) call the period from the second half of the XVI century until the beginning of the XIX century "Small Ice Age" (A.Monin, Yu.A. Shishkov "Climate History". L., 1979) or "Malaya Glacier Epoch "(E.L. Rua Ladyri" Climate History from 1000 years old ". L., 1971). They note that at that time there were not separate cold winters, but in general, a decrease in temperature on Earth.
Le Roa Ladyuri analyzed the data on the expansion of glaciers in the Alps and Carpathians. It indicates such a fact: The gold mines developed in the middle of the XV centuries were closed with ice with a thickness of 20 m, in the XVIII century the thickness of the ice was already 100 m. By 1875, despite the widespread recession held throughout the XIX century And the melting of glaciers, the thickness of the glacier over medieval mines in the high tatras was still 40 m. At the same time, as the French paleoclimatologist notes, the onset of glaciers and in the French Alps began. In the commune Chamonix-Mont Blanc, in the mountains of Savoy, "the offensive of glaciers was definitely started in 1570-1580."
Similar examples of Le Roa Ladyri indicates accurate dates and in other places Alps. In Switzerland, by 1588, testimonies include the expansion of the glacier in the Swiss Greendenwalde, and in 1589, the glacier descended from the mountains blocked the Valley of the Zas River. In the Penni Alps (in Italy near the border with Switzerland and France) in 1594-1595 also marked a noticeable expansion of glaciers. "In the Eastern Alps (Tyrol et al.) The glaciers occur equally and at the same time. The first information about this belongs to 1595, "writes Le Roa Ladyuri. And adds: - In 1599-1600, the curve of the development of glaciers reached its vertices for the entire Alps field. " From the same time, in written sources, there are endless complaints of residents of mountain villages to the fact that the glaciers are buried under them their pastures, fields and houses, washing so from the face of the Earth the whole settlements. In the XVII century, the expansion of glaciers continues.
It is consistent with the expansion of glaciers in Iceland, starting from the end of the XVI century and during the XVII century advancing on settlements. As a result, Le Roa Ladyri states, "Scandinavian glaciers synchronously with the Alpine glaciers and the glaciers of other areas of the world are experiencing the first, well-pronounced historical maximum, and" in the following years they will begin to come again. " So it lasted until the middle of the XVIII century.
The thickness of the glaciers of those centuries can really be called historical. On the chart of changes in the thickness of glaciers in Iceland and Norway over the past 10 thousand years, published in the book of Andrei Monina and Yuri Shishkov "Climate History" is clearly seen how the glacier thickness began to grow about 1600 by 1750 reached the level on which the glaciers kept In Europe, in the period of 8-5 thousand years BC
Is it wonder that contemporaries are fixed since the 1560s in Europe once again repeatedly repeatedly cold winters, which were accompanied by freezing large rivers and reservoirs? These cases are indicated, for example, in the book of Evgenia Borisenkova and Vasilia Passekoy "Movie-year chronicle of unusual phenomena of nature" (M., 1988). In December 1564, a powerful shelda in the Netherlands fully frozen and stood under the ice until the end of the first week of January 1565. The same cold winter was repeated in 1594/95, when the sheld and Rhine frozen. Sea and Strait frozen: in 1580 and 1658 - the Baltic Sea, in 1620/21 - Black and Strait Bosphorus, in 1659 - Strait Big Lest between the Baltic and Northern Seas (the minimum width of which is 3.7 km).
The end of the XVII century, when, according to Le Rua Peduri, the thickness of the glaciers in Europe reaches a historical maximum, was marked by the insignificant due to long harsh frosts. As noted in the book Borisenkova and Passekoy: "1692-1699 were noted in Western Europe with solid indigestive and hunger strikes."
One of the most terrible winters of a small glacial period fell on January-February 1709. Reading the description of those historical events, involuntarily try on modern ones: "From an extraordinary jury, like that did not remember her grandfathers, nor Pradeda ... Dzhibi residents of Russia and Western Europe. Birds, flying through the air, frozen. In general, many thousands of people, animals and trees died in Europe. In the vicinity of Venice, the Adriatic Sea was covered with standing ice. The coastal waters of England were covered with ice. Frozen hay, Thames. The ice on the Maas River reached 1.5 m. So great were frosts in the eastern part of North America. " No less than Lutes were winter 1739/40, 1787/88 and 1788/89.
In the XIX century, the small glacial period was replaced by warming and the harsh winters went into the past. Is it not returning now?
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