Glaciers of Russia: list and photos. Mountain glaciers of Russia

Some glaciers represent one of the most impressive sights in the world, in fact, we will tell you about them today.

Austfonna, Norway

This glacier is located on the Spitsbergen archipelago, and ranks first in size on the entire Old Continent. Its area is 8200 square kilometers.

Vatnajökull, Iceland

Slightly smaller area – 8100 sq. km - occupies the Vatnaekul glacier in Iceland. This glacier is the second largest in Europe. If we take the volume of the glacier as a criterion, then only the part protruding to the surface will be 3100 cubic kilometers.

Jostedalsbreen, Norway

It is the largest glacier in continental Europe. It covers an area of ​​487 square kilometers, however, unfortunately, the glacier is shrinking very quickly and there is a danger of its complete destruction.

Aletsch, Switzerland

The largest Alpine glacier is located in Switzerland, on the Valais. The total area of ​​this glacier is 117.6 square kilometers, and its length is more than 20 km. The Aletsch Glacier, as well as the nearby Jungfrau Mountains, have been declared a UNESCO World Heritage Site.

Schneeferner, Germany

In the region of the Bavarian Alps there is the most big glacier Germany, which, moreover, is the northernmost Alpine glacier. It is located in the Zugspitze massif (the highest mountain in the country), on the Zugspitzplatt plateau and its area covers about 3 hectares.

Pastors, Austria

The Austrian Shepherd Glacier lies in the Grossglockner massif, and is the largest glacier in the country. It is noteworthy that the name “pastors” is of Slavic origin and means a place for grazing sheep.

Southern Patagonian Ice Sheet, Chile and Argentina

It occupies a surface area of ​​16,800 square kilometers of the South Patagonian Shield and is considered the largest glacier in South America. Most of its territory is located in Chile - 14,200 square meters. km, and only 2600 belongs to Argentina. Streams diverge from the glacier. 50 km long, thus creating a huge lake.

Lambert Glacier, Antarctica

The largest and longest glacier in the world is the Lambert Glacier, which is located in East Antarctica. The glacier was discovered in 1956 and is estimated to be 400 miles long and 50 kilometers wide, which occupies approximately 10% of the entire ice continent.

Malaspina, USA

The glacier covers an area of ​​4275 square kilometers, located at the foot of Mount St. Elias in Alaska.

Fedchenko Glacier, Tajikistan

Fedchenko Glacier in Tajikistan is the longest glacier outside the polar zones. It is located at an altitude of 6000 meters above sea level. In addition, it is the largest glacier in the Pamir Mountains and among all Asian continents. The glacier is so huge that the size of its “tributaries” far exceeds the most powerful European glaciers.

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Determine which country of the South American continent we are talking about. The Country of Ancient Civilizations, the “archaeological museum” of South America. One of

"fish" powers of the world. The country has the largest alpine lake peace. By natural conditions is divided into 3 parts: Costa, Sierra, Selva. The country has huge reserves of copper. The country is home to the Quechua and Aymara Indian peoples. Two official languages: Spanish and Quechua.

It is necessary to enter the republics and the missing ones (numbers, names)

1. The region is located in the southern part of Altai; on its territory there is the highest peak of Siberia - Mount _____. The unusually picturesque landscapes of this region with the beautiful lake _____ are classified as World Natural Heritage Sites. (____).
2. The region is located in the south of the West Siberian Plain. From the confluence of the rivers ___ and ____, the largest river in Western Siberia, ____, originates here. This is the breadbasket of the entire region. The production of tractors, agricultural machinery, and carriages has been developed. The lakes of the Kulundinskaya steppe contain significant reserves of salts: table salt and Glauber salt (mirabilite). (____).
3. The largest coal mining basin is located here, and iron and polymetallic ores are also mined. Enterprises of the Siberian metallurgical base are concentrated in the region. In the south, in Mountain Shoria, a small Turkic-speaking people live ___. (___).
4. The center of the region is the easternmost millionaire city in Russia, the largest scientific center in Siberia. This is an important agricultural region of Siberia. The only hydroelectric power station in the region was built on the ____ river. Here is the largest endorheic, slightly saline lake in Western Siberia ___. (___).
5. Various landscapes are common in the region: from taiga to steppe. The center of the region - a millionaire city - is located on largest tributary Ob - river ___. Mechanical engineering, petrochemistry and oil refining are developed. This is a large agricultural region. (___).
6. On the territory of the region there is the world's largest ____ swamp. The regional center is located on the river of the same name, a tributary of the Ob. The famous economic geographer N.N. Baransky was born here. The largest timber processing complex is located in the region. (___).
7. The largest region in the country by area, which includes two autonomous districts, where the main centers of oil and gas production are located. The main city is the first Russian city in Siberia. (___).
8. Largest in terms of population and number of large cities autonomous region countries. This is the oil center of Siberia and all of Russia. The largest oil field is located here - ___. Two thirds of the district's territory is occupied by swamps. The forestry and fishing industries, fur trade, and woodworking are developed. (___).
9. More than 90% of Russian gas is produced here and the world's largest gas fields are located: ____ and ____. Most of the territory is tundra and forest-tundra. The main city was called Obdorsk until 1933; this is one of the basic centers for the development of northern Siberia. (___).

1)Which language family do most of the peoples of Europe belong to? 2) What type of reproduction does Europe belong to? 3)The capital of Poland?

4) What is the level of urbanization Foreign Europe?

5) The only colonial possession on the political map of the world?

6)Where is Europe's largest natural gas field located?

7) High natural population growth in Europe is characterized only by...?

8)The second most important branch of specialization in Europe?

9) The undisputed trendsetter is...?

10) the first place in Europe in the production of woolen fabrics is...?

11)The largest universal port in the world?

12)Which country does the Volvo car brand belong to?

13) The largest and most modern of the metallurgical plants built in seaports is located...?

Dedicated to my family, Yeoul, Kostya and Stas.

Glaciers on Earth and in the Solar System

About ten percent of the land is covered with glaciers - long-term masses of snow, firn(from him. Firn - last year's compacted granular snow) and ice, which have their own movement. These huge rivers of ice, cutting through valleys and grinding down mountains, pushing continents with their weight, store 80% of reserves fresh water of our planet.

The role of glaciers in evolution globe and the person is colossal. The last 2 million years of ice ages became a powerful impetus for the development of primates. Harsh weather conditions forced hominids to struggle for existence in cold conditions, living in caves, the appearance and development of clothing, and the widespread use of fire. The decrease in sea level due to the growth of glaciers and the drying of many isthmuses contributed to the migration of ancient people to America, Japan, Malaysia and Australia.

The largest centers of modern glaciation include:

• Antarctica - terra incognita, discovered only 190 years ago and became the record holder for the absolute minimum temperature on Earth: –89.4°C (1974); At this temperature, kerosene freezes;
• Greenland, deceptively named the Green Land, is the "icy heart" of the Northern Hemisphere;
• The Canadian Arctic archipelago and the majestic Cordillera, where one of the most picturesque and powerful centers of glaciation is located - Alaska, a real modern relic of the Pleistocene;
• the most ambitious area of ​​glaciation in Asia - the “abode of snow” Himalayas and Tibet;
• “roof of the world” Pamir;
• Andes;
• “heavenly mountains” Tien Shan and “black scree” Karakorum;
• surprisingly, there are glaciers even in Mexico, tropical Africa("sparkling mountain" Kilimanjaro, Mount Kenya and the Rwenzori Mountains) and in New Guinea!

The science that studies glaciers and other natural systems whose properties and dynamics are determined by ice is called glaciology(from lat. glacies- ice). "Ice" is a monomineral rock found in 15 crystalline modifications for which there are no names, but only code numbers. They differ different types crystal symmetry (or shape of the unit cell), the number of oxygen atoms in the cell and other physical parameters. The most common modification is hexagonal, but there are also cubic and tetragonal, etc. We conventionally denote all these modifications of the solid phase of water with one single word “ice”.

Ice and glaciers are found everywhere in the solar system: in the shadow of the craters of Mercury and the Moon; in the form of permafrost and polar caps of Mars; in the core of Jupiter, Saturn, Uranus and Neptune; on Europa, a satellite of Jupiter, completely covered, like a shell, with many kilometers of ice; on other moons of Jupiter - Ganymede and Callisto; on one of Saturn's moons - Enceladus, with the most pure ice the Solar System, where jets of water vapor hundreds of kilometers high escape from cracks in the ice shell at supersonic speeds; perhaps on the satellites of Uranus - Miranda, Neptune - Triton, Pluto - Charon; finally, in comets. However, by coincidence of astronomical circumstances, the Earth is a unique place where the existence of water on the surface is possible in three phases at once - liquid, solid and gaseous.

The fact is that ice is a very young mineral of the Earth. Ice is the last and most superficial mineral, not only in terms of specific gravity: If we distinguish the temperature stages of differentiation of matter in the process of formation of the Earth as an initially gaseous body, then ice formation represents the last step. It is for this reason that snow and ice on the surface of our planet are everywhere near the melting point and are subject to the slightest climate changes.

But if under the temperature conditions of the Earth water passes from one phase to another, then for cold Mars (with a temperature difference from –140°C to +20°C) water is mainly in the crystalline phase (although there are sublimation processes leading even to the formation clouds), and much more significant phase transitions are experienced not by water, but by carbon dioxide, falling as snow when the temperature drops, or evaporating when it rises (thus, the mass of the atmosphere of Mars changes from season to season by 25%).

Growth and melting of glaciers

For a glacier to form, a combination of climatic conditions and topography is necessary, under which the annual amount of snowfall (including snowstorms and avalanches) will exceed the loss ( ablation) due to melting and evaporation. Under such conditions, a mass of snow, firn and ice appears, which, under the influence of its own weight, begins to flow down the slope.

The glacier is of atmospheric sedimentary origin. In other words, every gram of ice, be it a modest glacier in the Khibiny Mountains or a giant ice dome of Antarctica, was brought by weightless snowflakes that fall year after year, millennium after millennium, in the cold regions of our planet. Thus, glaciers are a temporary stop of water between the atmosphere and the ocean.

Accordingly, if glaciers grow, then the level of the world's oceans drops (for example, up to 120 m during the last ice age); if they contract and retreat, then the sea rises. One of the consequences of this is the existence of relict areas on the Arctic shelf zone. underwater permafrost covered with thick water. During glaciations, the continental shelf, exposed due to lower sea levels, gradually froze. After the sea rose again, the permafrost thus formed ended up under the waters of the Arctic Ocean, where it continues to exist to this day due to the low temperature of sea water (–1.8°C).

If all the world's glaciers melted, sea levels would rise by 64–70 meters. Now the annual advance of the sea onto land occurs at a rate of 3.1 mm per year, of which about 2 mm is the result of an increase in the volume of water due to thermal expansion, and the remaining millimeter is the result of the intensive melting of mountain glaciers in Patagonia, Alaska and the Himalayas. IN lately this process is accelerating, increasingly affecting the glaciers of Greenland and West Antarctica, and, according to recent estimates, sea level rise could reach 200 cm by 2100. This will significantly change coastline, will erase more than one island from the world map and take away hundreds of millions of people in the prosperous Netherlands and poor Bangladesh, in the countries Pacific Ocean and the Caribbean, in other parts of the globe, coastal areas with a total area of ​​more than 1 million square kilometers.

Types of glaciers. Icebergs

Glaciologists distinguish the following main types of glaciers: mountain peak glaciers, ice domes and shields, slope glaciers, valley glaciers, reticulated glaciers systems(characteristic, for example, of Spitsbergen, where ice completely fills the valleys, and only the tops of the mountains remain above the surface of the glacier). In addition, as a continuation of land glaciers, they distinguish sea ​​glaciers and ice shelves, which are floating or bottom-based plates with an area of ​​up to several hundred thousand square kilometers (the largest ice shelf - the Ross Glacier in Antarctica - occupies 500 thousand km 2, which is approximately equal to the territory of Spain).

Ice shelves rise and fall with the tides. From time to time, giant ice islands break off from them - the so-called table icebergs, up to 500 m thick. Only one tenth of their volume is above water, which is why the movement of icebergs depends on to a greater extent from sea currents, and not from winds, which is why icebergs have more than once caused the death of ships. After the Titanic tragedy, icebergs are being carefully monitored. Nevertheless, disasters caused by icebergs still occur today - for example, the sinking of an oil tanker Exxon Valdez On March 24, 1989, it occurred off the coast of Alaska when a ship was trying to avoid a collision with an iceberg.

The tallest iceberg recorded in the Northern Hemisphere was 168 meters high. And the largest table iceberg ever described was observed on November 17, 1956 from the icebreaker Glager ( USS Glacier): its length was 375 km, its width was more than 100 km, and its area was more than 35 thousand km 2 (more than Taiwan or the island of Kyushu)!

Commercial transportation of icebergs to countries experiencing fresh water shortages has been seriously discussed since the 1950s. In 1973, one of these projects was proposed - with a budget of 30 million dollars. This project has attracted the attention of scientists and engineers from all over the world; It was headed by Saudi Prince Mohammed al-Faisal. But due to numerous technical problems and unresolved issues (for example, an iceberg that has capsized due to melting and a shift in the center of mass can, like an octopus, drag any cruiser towing it to the bottom), the implementation of the idea is postponed to the future.

It is not yet possible for humans to wrap an iceberg that is incommensurate in size with any ship on the planet and transport an ice island melting in warm waters and shrouded in fog across thousands of kilometers of ocean.

It is curious that when melting, iceberg ice sizzles like soda (“ Bergy selzer") - you can verify this at any polar institute if you are treated to a glass of whiskey with pieces of such ice. This is ancient air, compressed under high pressure(up to 20 atmospheres), escapes from the bubbles when melting. The air was trapped as the snow turned into firn and ice, and was then compressed by the enormous pressure of the glacier's mass. The story of the 16th century Dutch navigator Willem Barents has been preserved about how The iceberg near which his ship stood (near Novaya Zemlya) suddenly shattered into hundreds of pieces with a terrible noise, horrifying all the people on board.

Anatomy of a glacier

The glacier is conventionally divided into two parts: the upper - power supply area, where the accumulation and transformation of snow into firn and ice occurs, and the lower - ablation area, where the snow accumulated over the winter melts. The line separating these two areas is called glacier feeding boundary. Newly formed ice gradually flows from the upper feeding region to the lower ablation region, where melting occurs. Thus, the glacier is included in the process of geographic moisture exchange between the hydrosphere and the troposphere.

Irregularities, ledges, and an increase in the slope of the glacial bed change the relief of the glacial surface. In steep places where the stress in the ice is extremely high, ice falls and cracks can occur. Himalayan glacier Chatoru(mountainous region of Lagul, Lahaul) begins with a grandiose icefall 2100 m high! A real mess of giant columns and towers of ice (the so-called seracs) the icefall is literally impossible to cross.

The infamous icefall on Nepal's Khumbu glacier at the foot of Everest has cost the lives of many climbers attempting to navigate its diabolical surface. In 1951, a group of climbers led by Sir Edmund Hillary, during a reconnaissance of the surface of the glacier, along which the route of the first successful ascent of Everest was subsequently laid, crossed this forest of ice columns up to 20 meters high. As one of the participants recalled, the sudden roar and strong shaking of the surface under their feet greatly frightened the climbers, but, fortunately, no collapse occurred. One of the subsequent expeditions, in 1969, ended tragically: 6 people were crushed under the sounds of unexpectedly collapsing ice.

The depth of cracks in glaciers can exceed 40 meters, and the length can be several kilometers. Covered with snow, such gaps in the darkness of the glacial body are a death trap for climbers, snowmobiles or even all-terrain vehicles. Over time, cracks may close due to ice movement. There are cases where the unevacuated bodies of people who fell into cracks were literally frozen into the glacier. So, in 1820, on the slope of Mont Blanc, three guides were knocked down and thrown into a fault. snow avalanche- only 43 years later their bodies were discovered melted next to the tongue of a glacier three kilometers from the site of the tragedy.

Meltwater can significantly deepen cracks and turn them into part of the glacier's drainage system - glacial wells. They can reach 10 m in diameter and penetrate hundreds of meters into the glacial body to the very bottom.

A meltwater lake on the surface of a glacier in Greenland, 4 km long and 8 meters deep, was recently recorded to have disappeared in less than an hour and a half; at the same time, the water flow per second was greater than that of Niagara Falls. All this water reaches the glacier bed and serves as a lubricant, accelerating the sliding of the ice.

Glacier speed

Naturalist and mountaineer Franz Joseph Hugi made one of the first measurements of the speed of ice movement in 1827, and unexpectedly for himself. A hut was built on the glacier for overnight stays; When Hugi returned to the glacier a year later, he was surprised to find that the hut was in a completely different place.

The movement of glaciers is caused by two different processes - sliding glacial mass under its own weight along the bed and viscoplastic flow(or internal deformation when ice crystals change shape under stress and move relative to each other).

The speed of glacier movement can range from a few centimeters to more than 10 kilometers per year. Thus, in 1719, the advance of glaciers in the Alps occurred so quickly that residents were forced to turn to the authorities with a request to take action and force " damn beasts"(quote) go back. Complaints about glaciers were also written to the king by Norwegian peasants, whose farms were being destroyed by the advancing ice. It is known that in 1684 two Norwegian peasants were brought before a local court for non-payment of rent. When asked why they refused to pay, the peasants replied that their summer pastures were covered with impending ice. The authorities had to make observations to make sure that the glaciers were actually advancing - and as a result, we now have historical data on the fluctuations of these glaciers!

The glacier was considered the fastest glacier on Earth Colombia in Alaska (15 kilometers per year), but more recently the glacier took first place Jakobshavn(Jakobshavn) in Greenland (see the fantastic video of its collapse presented at a recent glaciology conference). The movement of this glacier can be felt while standing on its surface. In 2007, this giant river of ice, 6 kilometers wide and over 300 meters thick, producing about 35 billion tons of the world's tallest icebergs annually, was moving at a speed of 42.5 meters per day (15.5 kilometers per year)!

Pulsating glaciers can move even faster, the sudden movement of which can reach 300 meters per day!

The speed of ice movement within the glacial strata is not the same. Due to friction with the underlying surface, it is minimal at the glacier bed and maximum at the surface. This was first measured after a steel pipe was immersed in a 130-metre-deep hole drilled into a glacier. Measuring its curvature made it possible to construct a profile of the speed of ice movement.

In addition, the ice speed in the center of the glacier is higher compared to its outlying parts. The first transverse profile of the uneven distribution of glacier velocities was demonstrated by the Swiss scientist Jean Louis Agassiz in the forties of the 19th century. He left slats on the glacier, aligning them in a straight line; a year later, the straight line turned into a parabola, with its apex pointing downstream of the glacier.

The following tragic incident can be cited as a unique example illustrating the movement of a glacier. On August 2, 1947, a plane flying a commercial flight from Buenos Aires to Santiago disappeared without a trace 5 minutes before landing. Intensive searches led nowhere. The secret was revealed only half a century later: on one of the slopes of the Andes, at the peak Tupungato(Tupungato, 6800 m), in the area of ​​glacier melting, fragments of the fuselage and bodies of passengers began to melt out of the ice. Probably in 1947, due to poor visibility, the plane crashed into a slope, triggered an avalanche and was buried under its deposits in the glacier accumulation zone. It took 50 years for the debris to go through the full cycle of glacier material.

God's plow

The movement of glaciers destroys rocks and transports gigantic amounts of mineral material (the so-called moraine) - ranging from broken rock blocks to fine dust.

Thanks to the transport of moraine sediments, many amazing discoveries were made: for example, the main deposits were found from fragments of boulders transported by a glacier containing copper inclusions copper ore in Finland. In the USA, in the deposits of terminal moraines (from which one can judge the ancient distribution of glaciers), gold brought by glaciers (Indiana) and even diamonds weighing up to 21 carats (Wisconsin, Michigan, Ohio) were discovered. This caused many geologists to look north to Canada, where the glacier came from. There, between Lake Superior and Hudson Bay, kimberlite rocks were described - although scientists were never able to find kimberlite pipes.

The very idea that glaciers move was born out of a dispute about the origin of the huge erratic boulders. This is what geologists call large boulders (“wandering stones”) that are completely different in mineral composition from their surroundings (“a granite boulder on limestone looks as strange to trained eyes as a polar bear on the sidewalk,” one researcher liked to say).

One of these boulders (the famous “Thunder Stone”) became a pedestal for the Bronze Horseman in St. Petersburg. In Sweden there is a known limestone boulder 850 meters long, in Denmark there is a giant block of tertiary and cretaceous clays and sands 4 kilometers long. In England, in the county Huntingdonshire, 80 km north of London, an entire village was even built on one of the erratic slabs!

The “gouging” of hard bedrock by a glacier in the Alps can be up to 15 mm per year, in Alaska - 20 mm, which is comparable to river erosion. The erosive, transporting and accumulating activity of glaciers leaves such a colossal imprint on the face of the Earth that Jean-Louis Agassiz called glaciers “God’s plow”. Many of the planet's landscapes are the result of the activity of glaciers, which 20 thousand years ago covered about 30% of the earth's land.

All geologists recognize that the most complex geomorphological formations on Earth are associated with the growth, movement and degradation of glaciers. Erosion landforms such as punishment, similar to giants' chairs, and glacial cirques, trogs. Numerous moraine landforms nunataks And erratic boulders, eskers And fluvioglacial deposits. Are formed fjords, with wall heights of up to 1500 meters in Alaska and up to 1800 meters in Greenland and lengths of up to 220 kilometers in Norway or up to 350 kilometers in Greenland ( Nordvestfjord Scoresby & Sund East cost). The steep walls of the fjords are loved by base jumpers all over the world. Crazy height and slope allow you to make long jumps of up to 20 seconds of free fall into the void created by glaciers.

Dynamite and glacier thickness

The thickness of a mountain glacier can be tens or even hundreds of meters. The largest mountain glacier in Eurasia - Fedchenko Glacier in the Pamirs (Tajikistan) - has a length of 77 km and a thickness of more than 900 m.

The absolute record holders are the ice sheets of Greenland and Antarctica. For the first time, the thickness of ice in Greenland was measured during the expedition of the founder of the theory of continental drift Alfred Wegener in 1929-30. To do this, dynamite was detonated on the surface of the ice dome and the time required for the echo (elastic vibrations) reflected from the rock bed of the glacier to return to the surface was determined. Knowing the speed of propagation of elastic waves in ice (about 3700 m/s), the thickness of the ice can be calculated.

Today, the main methods of measuring the thickness of glaciers are seismic and radio sounding. It has been determined that the maximum ice depth in Greenland is about 3408 m, in Antarctica 4776 m ( Astrolabe subglacial basin)!

Subglacial Lake Vostok

As a result of seismic radar sounding, researchers made one of the last geographical discoveries XX century - the legendary subglacial Lake Vostok.

In absolute darkness, under the pressure of a four-kilometer thick layer of ice, there is a water reservoir with an area of ​​17.1 thousand km 2 (almost as Lake Ladoga) and a depth of up to 1500 meters - scientists called this body of water Lake Vostok. Its existence is due to its location in a geological fault and geothermal heating, which possibly supports the life of bacteria. Like other water bodies on Earth, Lake Vostok, under the influence of the gravity of the Moon and the Sun, undergoes ebbs and flows (1–2 cm). For this reason and because of the difference in depth and temperature, it is assumed that the water in the lake circulates.

Similar subglacial lakes have been discovered in Iceland; More than 280 such lakes are already known in Antarctica today, many of them are connected by subglacial channels. But Lake Vostok is isolated and the largest, which is why it is of greatest interest to scientists. Oxygen-rich water with a temperature of -2.65°C is under a pressure of about 350 bar.

The assumption of a very high oxygen content (up to 700–1200 mg/l) in lake water is based on the following reasoning: the measured density of ice at the boundary of the firn-ice transition is about 700–750 kg/m3. This relatively low value is due to the large number of air bubbles. Reaching the lower part of the glacial strata (where the pressure is about 300 bar and any gases “dissolve” in the ice, forming gas hydrates), the density increases to 900–950 kg/m3. This means that each specific unit of volume, melting at the bottom, brings at least 15% of air from each specific unit of surface volume (Zotikov, 2006)

The air is released and dissolved in the water or possibly trapped under pressure in the form of air siphons. This process took place over 15 million years; Accordingly, when the lake was formed, a huge amount of air melted from the ice. There are no analogues of water with such a high concentration of oxygen in nature (the maximum in lakes is about 14 mg/l). Therefore, the range of living organisms that could tolerate such extreme conditions is reduced to a very narrow framework oxygenophilic; Among the species known to science, there is not a single one capable of living in such conditions.

Biologists around the world are extremely interested in obtaining water samples from Lake Vostok, since analysis of ice cores obtained from a depth of 3667 meters as a result of drilling in the immediate vicinity of Lake Vostok itself showed the complete absence of any microorganisms, and these cores are already of interest to biologists they don't represent. But a technical solution to the issue of opening and penetrating an ecosystem sealed for more than ten million years has not yet been found. The point is not only that 50 tons of kerosene-based drilling fluid are now poured into the well, which prevents the well from being closed by ice pressure and freezing of the drill, but also that any man-made mechanism can disrupt the biological balance and pollute the water by introducing into it microorganisms that previously existed there.

Perhaps similar subglacial lakes, or even seas, exist on Jupiter’s moon Europa and Saturn’s moon Enceladus, under tens or even hundreds of kilometers of ice. It is on these hypothetical seas that astrobiologists pin their greatest hopes when searching for extraterrestrial life within the Solar System and are already making plans on how, with the help of nuclear energy (the so-called NASA cryobot), it will be possible to overcome hundreds of kilometers of ice and penetrate into the water space. (On February 18, 2009, NASA and the European Space Agency ESA officially announced that Europe would be the destination of the next historic solar system exploration mission, scheduled to arrive in orbit in 2026.)

Glacioisostasy

The colossal volumes of modern ice sheets (Greenland - 2.9 million km 3, Antarctica - 24.7 million km 3) for hundreds and thousands of meters push the lithosphere with their mass into the semi-liquid asthenosphere (this is the upper, least viscous part of the earth's mantle). As a result, some parts of Greenland are more than 300 m below sea level, and Antarctica is 2555 m below sea level ( Bentley Subglacial Trench)! In fact, the continental beds of Antarctica and Greenland are not single massifs, but huge archipelagos of islands.

After the disappearance of the glacier, the so-called glacioisostatic uplift, conditioned simple principle buoyancy, described by Archimedes: lighter lithospheric plates slowly float to the surface. For example, part of Canada or the Scandinavian Peninsula, which were covered by an ice sheet more than 10 thousand years ago, still continue to experience isostatic uplift at a rate of up to 11 mm per year (it is known that even the Eskimos paid attention to this phenomenon and argued about whether it was rising whether it is land or whether the sea is sinking). It is estimated that if all the ice on Greenland melts, the island will rise by about 600 meters.

It is difficult to find an inhabited area more susceptible to glacioisostatic uplift than islands Replot Skerry Guard in the Gulf of Bothnia. Over the past two hundred years, during which the islands have risen from under the water by about 9 mm per year, the land area has increased by 35%. Residents of the islands gather once every 50 years and happily divide up new plots of land.

Gravity and ice

Just a few years ago, when I was graduating from university, the question of the mass balance of Antarctica and Greenland in the context of global warming was controversial. Whether the volume of these giant ice domes is decreasing or increasing has been very difficult to determine. It has been hypothesized that perhaps warming is bringing more precipitation, and as a result, glaciers are growing rather than shrinking. Data obtained from the GRACE satellites, launched by NASA in 2002, clarified the situation and refuted these ideas.

The greater the mass, the greater the gravity. Since the surface of the Earth is heterogeneous and includes gigantic mountain ranges, vast oceans, deserts, etc., the gravitational field of the Earth is also heterogeneous. This gravitational anomaly and its change over time are measured by two satellites - one follows the other and records the relative deviation of the trajectory when flying over objects of different masses. For example, roughly speaking, when flying over Antarctica, the satellite’s trajectory will be a little closer to the Earth, and over the ocean, on the contrary, further.

Long-term observations of flights in the same place make it possible to judge by changes in gravity how the mass has changed. The results showed that the volume of Greenland's glaciers is decreasing annually by approximately 248 km 3, and that of Antarctica's glaciers by 152 km 3. By the way, according to maps compiled with the help of GRACE satellites, not only the process of reduction in the volume of glaciers is recorded, but also the above-mentioned process of glacioisostatic uplift of continental plates.

For example, for the central part of Canada, due to glacioisostatic uplift, an increase in mass (or gravity) was recorded, and for neighboring Greenland - a decrease, due to intensive melting of glaciers.

Planetary significance of glaciers

According to Academician Kotlyakov, “ The development of the geographic environment throughout the Earth is determined by the balance of heat and moisture, which largely depends on the characteristics of the distribution and transformation of ice. To convert water from solid state liquid requires a huge amount of energy. At the same time, the transformation of water into ice is accompanied by the release of energy (approximately 35% of the Earth’s external heat turnover)" The spring melting of ice and snow cools the earth and prevents it from warming up quickly; Ice formation in winter warms and prevents it from cooling quickly. If there were no ice, then the temperature differences on Earth would be much greater, summer heat- stronger, frosts - more severe.

Taking into account seasonal snow and ice cover, it can be assumed that snow and ice cover from 30% to 50% of the Earth's surface. The most important importance of ice for the planet's climate is associated with its high reflectivity - 40% (for snow covering glaciers - 95%), due to which significant cooling of the surface occurs over vast areas. That is, glaciers are not only invaluable reserves of fresh water, but also sources of strong cooling of the Earth.

An interesting consequence of the reduction in the mass of glaciation in Greenland and Antarctica was the weakening gravitational force, attracting huge masses of ocean water, and a change in the angle of inclination of the earth's axis. The first is a simple consequence of the law of gravity: the less mass, the less attraction; the second is that the Greenland ice sheet loads the globe asymmetrically, and this affects the rotation of the Earth: a change in this mass affects the planet’s adaptation to the new symmetry of mass, due to which the Earth’s axis shifts annually (up to 6 cm per year).

The first guess about the gravitational influence of glaciation mass on sea level was made by the French mathematician Joseph Alphonse Adhémar, 1797–1862 (he was also the first scientist to point out the connection between ice ages and astronomical factors; after him the theory was developed by Kroll (see James Croll) and Milankovic). Adhemar tried to estimate the thickness of the ice in Antarctica by comparing the depths of the Arctic and Southern Oceans. His idea was that the depth of the Southern Ocean is much greater than the depth of the Arctic Ocean due to the strong attraction of water masses by the giant gravitational field of the Antarctic ice cap. According to his calculations, to maintain such a strong difference between the water levels of the north and south, the thickness of the ice cover of Antarctica should have been 90 km.

Today it is clear that all these assumptions are incorrect, except that the phenomenon still occurs, but with a lower magnitude - and its effect can radially spread up to 2000 km. The implications of this effect are that the rise in global sea levels as a result of melting glaciers will be uneven (although current models incorrectly assume an even distribution). As a result, in some coastal areas sea level will rise 5–30% above average (northeastern Pacific and southern Indian Oceans), and in some - lower ( South America, western, southern and eastern shores of Eurasia) (Mitrovica et al., 2009).

Frozen millennia - a revolution in paleoclimatology

On May 24, 1954, at 4 o'clock in the morning, Danish paleoclimatologist Willi Dansgaard was racing on a bicycle through deserted streets to the central post office with a huge envelope covered with 35 stamps and addressed to the editors of a scientific publication. Geochimica et Cosmochimica Acta. The envelope contained the manuscript of an article, which he was in a hurry to publish as soon as possible. He was struck by a fantastic idea, which would later revolutionize the climate sciences of ancient eras and which he would develop throughout his life.

Dansgaard's research showed that the amount of heavy isotopes in sediments can determine the temperature at which they were formed. And he thought: what actually prevents us from determining the temperature of past years by simply taking and analyzing the chemical composition of the water of that time? Nothing! The next logical question: where to get ancient water? In glacial ice! Where can I get ancient glacial ice? In Greenland!

This amazing idea was born several years before the technology for deep glacier drilling was developed. When the technological issue was resolved, an amazing thing happened: scientists discovered an incredible way to travel into the Earth's past. With every centimeter of ice drilled, the blades of their drills began to plunge deeper and deeper into paleohistory, revealing ever more ancient secrets of climate. Every ice core pulled out of a hole was a time capsule.

By deciphering the secret script written in hieroglyphs of a whole variety of chemical elements and particles, spores, pollen and bubbles of ancient air hundreds of thousands of years old, you can obtain invaluable information about irretrievably lost millennia, worlds, climates and phenomena.

Time machine 4000 m deep

The age of the oldest Antarctic ice from maximum depths (more than 3,500 meters), the search for which is still ongoing, is estimated at about one and a half million years. Chemical analysis of these samples allows us to get an idea of ​​the ancient climate of the Earth, the news of which was brought and preserved in the form of chemical elements by weightless snowflakes that fell from the skies hundreds of thousands of years ago.

This is similar to the story of Baron Munchausen's journey through Russia. During a hunt somewhere in Siberia, there was a terrible frost, and the baron, trying to call his friends, blew his horn. But to no avail, as the sound froze in the horn and only thawed out the next morning in the sun. Roughly the same thing is happening today in the cold laboratories of the world under electron tunneling microscopes and mass spectrometers. Ice cores from Greenland and Antarctica are many kilometers long time machines, going back centuries and millennia. The deepest to this day remains the legendary well drilled under the Vostok station (3677 meters). Thanks to it, the connection between changes in temperature and the content of carbon dioxide in the atmosphere over the past 400 thousand years was shown for the first time and ultra-long-term suspended animation of microbes was discovered.

Detailed paleoreconstructions of air temperature are based on an analysis of the isotopic composition of cores - namely, the percentage of the heavy oxygen isotope 18 O (its average content in nature is about 0.2% of all oxygen atoms). Water molecules containing this isotope of oxygen are more difficult to evaporate and condense more easily. Therefore, for example, in water vapor above the sea surface the content of 18 O is lower than in sea ​​water. Conversely, water molecules containing 18 O are more likely to participate in condensation on the surface of snow crystals forming in clouds, due to which their content in precipitation is higher than in the water vapor from which precipitation is formed.

The lower the temperature at which precipitation is formed, the stronger this effect manifests itself, that is, the more 18 O it contains. Therefore, by assessing the isotopic composition of snow or ice, it is possible to estimate the temperature at which precipitation was formed.

And then, using known altitude temperature profiles, estimate what the surface air temperature was hundreds of thousands of years ago, when a snowflake first fell on the Antarctic dome to turn into ice, which will be extracted today from a depth of several kilometers during drilling.

The snow that falls annually carefully preserves not only information about air temperature on the petals of snowflakes. The number of parameters measured in laboratory analysis is currently enormous. Tiny ice crystals record signals from volcanic eruptions, nuclear tests, the Chernobyl disaster, anthropogenic lead levels, dust storms, etc.

The amount of tritium (3H) and carbon-14 (14C) can be used to date the age of the ice. Both of these methods have been elegantly demonstrated on vintage wines - the years on the labels perfectly match the dates calculated from the analyses. It’s just that this pleasure is expensive, and wine A there is a lot of lime needed for analysis...

Information about history solar activity can be quantified by the nitrate (NO 3 –) content of glacial ice. Heavy nitrate molecules are formed from NO in the upper layers of the atmosphere under the influence of ionizing cosmic radiation (protons from solar flares, galactic radiation) as a result of a chain of transformations of nitrogen oxide (N 2 O) entering the atmosphere from the soil, nitrogen fertilizers and fuel combustion products (N 2 O + O → 2NO). After formation, the hydrated anion falls out with precipitation, some of which ends up buried in the glacier along with the next snowfall.

Beryllium-10 (10Be) isotopes provide insight into the intensity of deep space cosmic rays bombarding the Earth and changes in our planet's magnetic field.

The changes in the composition of the atmosphere over the past hundreds of thousands of years were told by small bubbles in the ice, like bottles thrown into the ocean of history, preserving for us samples of ancient air. They showed that over the past 400 thousand years, the content of carbon dioxide (CO 2) and methane (CH 4) in the atmosphere today is the highest.

Today, laboratories already store thousands of meters of ice cores for future analysis. In Greenland and Antarctica alone (that is, not counting mountain glaciers), a total of about 30 km of ice cores have been drilled and recovered!

Ice age theory

The beginning of modern glaciology was laid by the theory of ice ages that appeared in the first half of the 19th century. The idea that glaciers in the past extended hundreds or thousands of kilometers to the south previously seemed unthinkable. As one of the first glaciologists in Russia, Pyotr Kropotkin (yes, that same one), wrote, “ at that time, belief in an ice sheet reaching Europe was considered an impermissible heresy...».

The founder and main defender of the glacial theory was Jean Louis Agassiz. In 1839 he wrote: " The development of these huge ice sheets would have led to the destruction of all organic life on the surface. The lands of Europe formerly covered tropical vegetation and inhabited by herds of elephants, hippopotamuses and giant carnivores, were buried under the growing ice covering the plains, lakes, seas and mountain plateaus.<...>All that remained was the silence of death... The springs dried up, the rivers froze, and the rays of the sun rising above the frozen shores... met only a whisper northern winds and the roar of cracks opening in the middle of the surface giant ocean ice.»

Most geologists of the time, little familiar with Switzerland and the mountains, ignored the theory and were unable to even believe in the plasticity of ice, let alone imagine the thickness of the glacial strata described by Agassiz. This continued until the first scientific expedition to Greenland (1853–55), led by Elisha Kent Kane, reported complete glaciation of the island (“ an ocean of ice of infinite size»).

The recognition of the Ice Age theory had an incredible impact on the development of modern natural science. The next key question was the reason for the change ice ages and interglacial. At the beginning of the 20th century, the Serbian mathematician and engineer Milutin Milanković developed mathematical theory, which describes the dependence of climate change on changes in the orbital parameters of the planet, and devoted all his time to calculations to prove the validity of his theory, namely, to determining the cyclic change in the amount of solar radiation entering the Earth (the so-called insolation). The Earth, spinning in the void, is in a gravitational web of complex interactions between all objects solar system. As a result of orbital cyclic changes ( eccentricity earth's orbit, precession And nutation the tilt of the earth's axis) the amount of solar energy entering the earth changes. Milankovitch found the following cycles: 100 thousand years, 41 thousand years and 21 thousand years.

Unfortunately, the scientist himself did not live to see the day when his insight was elegantly and flawlessly proven by paleoceanographer John Imbrie. Imbrie assessed past temperature changes by studying cores from the floor of the Indian Ocean. The analysis was based on the following phenomenon: different types of plankton prefer different, strictly defined temperatures. Every year, the skeletons of these organisms settle on the ocean floor. By lifting this layered cake from the bottom and identifying the species, we can judge how the temperature changed. The paleotemperature variations determined in this way surprisingly coincided with the Milankovitch cycles.

Today we know that cold glacial eras were followed by warm interglacials. Complete glaciation of the globe (according to the so-called theory " snowy coma") supposedly took place 800–630 million years ago. Last glaciation Quaternary period ended 10 thousand years ago.

The ice domes of Antarctica and Greenland are relics of past glaciations; if they disappear now, they will not be able to recover. During periods of glaciation, continental ice sheets covered up to 30% of the globe's land mass. So, 150 thousand years ago the thickness glacial ice over Moscow was about a kilometer, and over Canada - about 4 km!

The era in which human civilization now lives and develops is called ice age, interglacial period. According to calculations made on the basis of Milankovitch's orbital climate theory, the next glaciation will occur in 20 thousand years. But the question remains whether the orbital factor will be able to overcome the anthropogenic one. The fact is that without the natural greenhouse effect, our planet would have an average temperature of –6°C, instead of today’s +15°C. That is, the difference is 21°C. Greenhouse effect has always existed, but human activity greatly enhances this effect. Now the carbon dioxide content in the atmosphere is the highest in the last 800 thousand years - 0.038% (while previous maximums did not exceed 0.03%).

Today, glaciers around the world (with some exceptions) are rapidly shrinking; the same goes for sea ​​ice, permafrost and snow cover. It is estimated that half of the world's mountain glaciation will disappear by 2100. About 1.5–2 billion people inhabit various countries Asia, Europe and America may face the fact that rivers fed by meltwater from glaciers will dry up. At the same time, rising sea levels will rob people of their land in the Pacific and Indian Oceans, the Caribbean and Europe.

Wrath of the Titans - Glacial Disasters

Increasing technogenic impact on the planet's climate may increase the likelihood of natural disasters associated with glaciers. Masses of ice have a gigantic potential energy, the implementation of which could have dire consequences. Some time ago, a video of a small column of ice collapsing into the water and the subsequent wave that washed away a group of tourists from nearby rocks circulated on the Internet. Similar waves 30 meters high and 300 meters long were observed in Greenland.

Glacial catastrophe that occurred in North Ossetia September 20, 2002, was recorded on all seismometers in the Caucasus. Glacier collapse Kolka provoked a gigantic glacial collapse - 100 million m 3 of ice, stones and water rushed through the Karmadon Gorge at a speed of 180 km per hour. Mudflow splashes tore away loose sediments of the valley sides in places up to 140 meters high. 125 people died.

One of the worst glacial disasters in the world was the collapse of the northern slope of the mountain. Huascaran in Peru in 1970. The magnitude 7.7 earthquake triggered an avalanche of millions of tons of snow, ice and rocks (50 million m3). The collapse stopped only after 16 kilometers; two cities buried under rubble turned into a mass grave for 20 thousand people.

Another type of hazard posed by glaciers is the outburst of dammed glacial lakes that occur between the melting glacier and the terminal moraine. The height of terminal moraines can reach 100 m, creating enormous potential for the formation of lakes and their subsequent outburst.

In 1555, a lake breakthrough in Nepal covered an area of ​​about 450 km 2 with sediments, and in some places the thickness of these sediments reached 60 m (the height of a 20-story building)! In 1941, the intense melting of Peru's glaciers contributed to the growth of dammed lakes. The breakthrough of one of them killed 6,000 people. In 1963, as a result of the movement of the pulsating Medvezhiy glacier in the Pamirs, a lake 80 meters deep appeared. When the ice dam was broken, a devastating torrent of water and subsequent mudflow rushed down the valley, destroying the power plant and many homes.

The most monstrous outburst of a glacial lake occurred through the Hudson Strait in sea ​​Labrador about 12,900 years ago. Breakthrough Lake Agassiz, with an area larger than the Caspian Sea, caused an abnormally rapid (over 10 years) cooling of the North Atlantic climate (by 5°C in England), known as Younger Dryas(see Younger Dryas) and discovered in the analysis of Greenland ice cores. A huge amount of fresh water has disrupted thermohaline circulation Atlantic Ocean, which blocked the transfer of heat by currents from low latitudes. Today, such an abrupt process is feared due to global warming, which is desalinating the waters of the North Atlantic.

Nowadays, due to the accelerated melting of the world's glaciers, the size of dammed lakes is increasing and, accordingly, the risk of their breakthrough is growing.

In the Himalayas alone, 95% of whose glaciers are rapidly melting, there are about 340 potentially dangerous lakes. In 1994, in Bhutan, 10 million cubic meters of water spilled from one of these lakes and traveled 80 kilometers at tremendous speed, killing 21 people.

According to forecasts, outburst of glacial lakes could become an annual disaster. Millions of people in Pakistan, India, Nepal, Bhutan and Tibet will not only face the inevitable loss of water resources due to disappearing glaciers, but also face the deadly danger of lake outbursts. Hydroelectric power stations, villages, and infrastructure can be destroyed in an instant by terrible mudflows.

Another type of glacial catastrophe is lahars, resulting from volcanic eruptions covered ice caps. The meeting of ice and lava gives rise to gigantic volcanogenic mud mudflows, typical of the country of “fire and ice” of Iceland, Kamchatka, Alaska and even on Elbrus. Lahars can reach monstrous sizes, being the largest among all types of mudflows: their length can reach 300 km, and their volume can reach 500 million m3.

On the night of November 13, 1985, residents of a Colombian city Armero(Armero) woke up from a crazy noise: a volcanic mudflow swept through their city, washing away all the houses and structures in its path - its seething liquid claimed the lives of 30 thousand people. Another tragic incident occurred on the fateful Christmas evening of 1953 in New Zealand - the breakthrough of a lake from an icy crater of a volcano triggered a lahar that washed away a railway bridge literally in front of the train. The locomotive and five carriages carrying 151 passengers plunged and disappeared forever into the rushing current.

In addition, volcanoes can simply destroy glaciers - for example, a monstrous eruption of a North American volcano St Helens(Saint Helens) removed 400 meters of the mountain's height along with 70% of the volume of glaciers.

Ice people

Harsh conditions The conditions in which glaciologists have to work are perhaps some of the most difficult that modern scientists face. B O Most field observations involve working in cold, inaccessible and remote parts of the globe, with harsh solar radiation and insufficient oxygen. In addition, glaciology often combines mountaineering with science, thereby making the profession deadly.

Frostbite is familiar to many glaciologists, which is why, for example, a former professor at my institute had his fingers and toes amputated. Even in a comfortable laboratory, temperatures can drop to -50°C. In the polar regions, all-terrain vehicles and snowmobiles sometimes fall into 30-40-meter cracks; severe snowstorms often make the high-altitude workdays of researchers a real hell and claim more than one life every year. This is a job for the strong and hardy people, sincerely devoted to their work and the endless beauty of the mountains and poles.

Used literature:

• Adhemar J. A., 1842. Revolutions of the Sea. Deluges Periodiques, Paris.
• Bailey, R. H., 1982. Glacier. Planet Earth. Time-Life Books, Alexandria, Virginia, USA, 176 p.
• Clark S., 2007. The Sun Kings: The Unexpected Tragedy of Richard Carrington and the Tale of How Modern Astronomy Began. Princeton University Press, 224 p.
• Dansgaard W., 2004. Frozen Annals - Greenland Ice Sheet Research. The Niels Bohr Institute, University of Copenhagen, 124 p.
• EPICA community members, 2004. Eight glacial cycles from an Antarctic ice core. Nature, 429 (10 June 2004), 623–628.
• Fujita, K., and O. Abe. 2006. Stable isotopes in daily precipitation at Dome Fuji, East Antarctica, Geophys. Res. Lett., 33 , L18503, doi:10.1029/2006GL026936.
• GRACE (the Gravity Recovery and Climate Experiment).
• Hambrey M. and Alean J., 2004, Glaciers (2nd edition), Cambridge University Press, UK, 376 p.
• Heki, K. 2008. Changing earth as shown by gravity (PDF, 221 KB). Littera Populi - Hokkaido University's public relations magazine, June 2008, 34, 26–27.
• Glacial pace picks up // In the Field (The Nature reporters" blog from conferences and events).
• Imbrie, J., and Imbrie, K. P., 1986. Ice Ages: Solving the Mystery. Cambridge, Harvard University Press, 224 p.
• IPCC, 2007: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 996 p.
• Kaufman S. and Libby W. L., 1954. The Natural Distribution of Tritium // Physical Review, 93, No. 6, (15 March 1954), p. 1337–1344.
• Komori, J. 2008. Recent expansions of glacial lakes in the Bhutan Himalayas. Quaternary International, 184 , 177–186.
• Lynas M., 2008. Six Degrees: Our Future on a Hotter Planet // National Geographic, 336 p.
• Mitrovica, J. X., Gomez, N. and P. U. Clark, 2009. The Sea-Level Fingerprint of West Antarctic Collapse. Science. Vol. 323.No. 5915 (6 February 2009) p. 753. DOI: 10.1126/science.1166510.
• Pfeffer W. T., Harper J. T., O’Neel S., 2008. Kinematic constraints on glacier contributions to 21st-century sea level rise. Science, 321 (5 September 2008), p. 1340–1343.
• Prockter L. M., 2005. Ice in the Solar System. Johns Hopkins APL Technical Digest. Volume 26. Number 2 (2005), p. 175–178.
• Rampino M. R., Self S., Fairbridge R. W., 1979. Can rapid climatic change cause volcanic eruptions? // Science, 206 (16 November 1979), no. 4420, p. 826–829.
• Rapp, D. 2009. Ice Ages and Interglacials. Measurments, Interpretation and Models. Springer, UK, 263 p.
• Svensson, A., S. W. Nielsen, S. Kipfstuhl, S. J. Johnsen, J. P. Steffensen, M. Bigler, U. Ruth, and R. Röthlisberger. 2005. Visual stratigraphy of the North Greenland Ice Core Project (NorthGRIP) ice core during the last glacial period, J. Geophys. Res., 110 , D02108, doi:10.1029/2004JD005134.
• Velicogna I. and Wahr J., 2006. Acceleration of Greenland ice mass loss in spring 2004 // Nature, 443 (21 September 2006), p. 329–331.
• Velicogna I. and Wahr J., 2006. Measurements of time-variable gravity show mass loss in Antarctica // Science, 311 (24 March 2006), no. 5768, p. 1754–1756.
• Zotikov I. A., 2006. The Antarctic Subglacial Lake Vostok. Glaciology, Biology and Planetology. Springer–Verlag, Berlin, Heidelberg, New York, 144 p.
• Voitkovsky K.F., 1999. Fundamentals of glaciology. Science, Moscow, 255 p.
• Glaciological dictionary. Ed. V. M. Kotlyakova. L., GIMIZ, 1984, 528 p.
• Zhigarev V. A., 1997. Oceanic cryolithozone. M., Moscow State University, 318 p.
• Kalesnik S.V., 1963. Essays on glaciology. State Publishing House geographical literature, Moscow, 551 p.
• Kechina K.I., 2004. The valley that became an icy grave // ​​BBC. Photo report: September 21, 2004.
• Kotlyakov V.M., 1968. Snow Cover of the Earth and Glaciers. L., GIMIZ, 1968, 480 p.
• Podolsky E. A., 2008. Unexpected perspective. Jean Louis Rodolphe Agassiz, “Elements”, March 14, 2008 (21 pp., expanded version).
• Popov A.I., Rosenbaum G.E., Tumel N.V., 1985. Cryolithology. Moscow University Publishing House, 239 p.

Glaciers are an extraordinary miracle of nature that slowly moves across the surface of the Earth. This accumulation of eternal ice captures and transports rocks along its path, forming unique landscapes such as moraines and karas. Sometimes the glacier stops moving and the so-called dead ice forms.

Some glaciers, moving a short distance in big lakes or seas, form a zone where splitting occurs and, as a result, drifting icebergs.

Geographical feature (meaning)

Glaciers appear in places where the accumulated mass of snow and ice significantly exceeds the mass of melting snow. And after many years, a glacier will form in such a region.

Glaciers are the largest reservoirs of fresh water on Earth. Most glaciers accumulate water during the winter season and release it as meltwater. Such waters are especially useful in mountainous regions of the planet, where such water is used by people who live in areas where there is little precipitation. Glacier meltwater is also a source for the existence of flora and fauna.

Characteristics and types of glaciers

According to the method of movement and visual outlines, glaciers are classified into two types: cover (continental) and mountain. Ice sheet glaciers occupy 98% of the total area of ​​planetary glaciation, and mountain glaciers occupy almost 1.5%

Continental glaciers are giant ice sheets located in Antarctica and Greenland. Glaciers of this type have flat-convex outlines that do not depend on the typical topography. Snow accumulates in the center of the glacier, and consumption occurs mainly on the outskirts. The ice of the cover glacier moves in a radial direction - from the center to the periphery, where the ice that is afloat breaks off.

Mountain-type glaciers are small in size, but different forms, which depend on their content. All glaciers of this type have clearly defined areas of feeding, transportation and melting. Nutrition is carried out with the help of snow, avalanches, a little sublimation of water vapor and snow transfer by the wind.

The largest glaciers

The largest glacier in the world is the Lambert Glacier, which is located in Antarctica. The length is 515 kilometers, and the width ranges from 30 to 120 kilometers, the depth of the glacier is 2.5 km. The entire surface of the glacier is cut by a large number of cracks. The glacier was discovered in the 50s of the twentieth century by the Australian cartographer Lambert.

In Norway (Svalbard archipelago) there is the Austfonna glacier, which leads the list of the largest glaciers in the Old Continent by area (8200 km2).

(Vatnajökull Glacier and Grimsuod Volcano)

In Iceland there is the Vatnajökull glacier, which ranks second in Europe in terms of area (8100 km2). The largest in mainland Europe is the Jostedalsbreen glacier (1230 km2), which is a wide plateau with numerous ice branches.

Melting glaciers - causes and consequences

The most dangerous of all modern natural processes is the melting of glaciers. Why is this happening? The planet is currently heating up - this is the result of the release of greenhouse gases into the atmosphere that are produced by humanity. As a result, the average temperature on Earth also rises. Since ice is the repository of fresh water on the planet, its reserves under intense global warming will end sooner or later. Glaciers are also climate stabilizers on the planet. Due to the amount of ice that has melted, salt water is evenly diluted with fresh water, which has a special impact on the level of air humidity, precipitation, and temperature indicators in both the summer and winter seasons.