Famous glaciers. The largest glaciers on earth

There is so much we do not know yet.

The Ross Ice Shelf in Antarctica is currently the largest floating block of ice in the world: the size of a glacier, no more, no less, with Spain, and a thickness of almost a kilometer. The ocean below it is regarded by experts as one of the most important but least understood parts of the climate system.

A team from the New Zealand Ross Ice Shelf Program melted a hole hundreds of meters down to explore the ocean and reveal the glacier's vulnerability to climate change. Their measurements showed that the ocean is heating and renewing, but not in the ways that everyone expected.

The hidden ocean.

Per last centuries, all the largest blocks of ice were found near the shores of Antarctica. These hulks hold back the Antarctic ice sheet, which, if released into the ocean and melted further, can raise sea levels so much that it will forever change the landscape of our planet.

An ice shelf looks like a giant plate of ice that forms when ordinary glaciers break away from land and merge as they float alongside the coast.

Ice shelves lose ice as a result of breaking off large pieces from them, or by melting ice from below. Because the water flowing under the Ross Ice Shelf is cold (minus 1.9 degrees Celsius), it is called a "cold cavity."

If the water warms up, the future of the ice shelf and upstream ice could change instantly. However, for now, the ocean located under the glacier has been excluded from all current models of the future Earth's climate.

In the late 1970s, international group scientists made an attempt to explore this ocean. Over the course of five years, the team has repeatedly tried to drill ice using several types of drills, but in vain. Now, with new and improved technology, the New Zealand team completed the job in one season.

The main conclusion is that sea ​​water circulates through the cavity, flowing into the seabed as relatively warm, salty water... She eventually finds her way to the shore - except, of course, coastline under the ice (800 meters down).

There it begins to melt the ice shelf from below and then flows through the bottom of the glacier back to the open ocean.

Peering through the hole into the ice.

A New Zealand team, including drillers, glaciologists, biologists, seismologists, oceanographers, worked from November to January, supported by tracked vehicles and, if local weather permitted, DHC-6 aircraft flew in to help.

As is often the case in polar oceanography, getting to the ocean was the most difficult part. The team was faced with the task of melting a well several hundred meters deep and only 25 centimeters in diameter! But as soon as the well reaches a depth of 300 meters, the task is greatly simplified. The risk of biological pollution in such conditions is reduced by many percent, than if the study was carried out, for example, in the jungle. Nevertheless, the threat of freezing of all the tools or the well itself has not been canceled.

Moving world

The team is located right in the middle of the glacier. But if their camp stood motionless, then the same could not be said about everything around.

The ocean is slowly circulating, possibly renewing itself every few years. The ice is moving too, about 1.6 meters every day. The ice sheet floats under its own weight, inexorably stretches to the edge of the ice shelf, where it breaks like massive icebergs on rare occasions. Also, the plate sinks and floats with daily tides.

The ice shelf, in addition to melting, can grow in size. Snowdrifts can form at the top, and water freezes at the bottom.

Thus, not a single thing in this cold world stands still. Interesting fact: The explorers' camp is located 160 kilometers from the place where Robert Falcon Scott and two members of his team were buried centuries ago, on their return from the South Pole. Therefore, it is safe to say that their bodies also move from place to place.

What is the future in store for us?

If the ocean under the ice heats up, what does that mean for the Ross Ice Shelf, ice sheet what it is holding back and the future sea level?

The team collected detailed data on temperature and salinity to understand how the ocean circulates within the cavity. They will be able to use this data for tests and computer simulations, as well as to assess whether the ice on the bottom of the ice shelf is melting or vice versa, the water freezes and the bottom part grows.

But even now we can say that compared to the end of the 70s, the temperature in the ocean has become warmer. In addition, the concentration of salt in the ocean has decreased. It was also found that the bottom of the glacier was covered with crystals. The same crystals can be seen in sea ​​ice that floats next to the ice shelves. But this layer of crystals was not as massive as on the Aymery Ice Shelf.

None of the above are included in modern climate models. Neither the effect of warm, salty water flowing into the cavity, nor very cold surface waters, nor ice crystals affecting heat transfer to ice, or ocean mixing on ice fronts.

It is not entirely clear whether the water under the glacier plays an important role in how the world's oceans work, but it can be said for sure that it affects the ice shelf.

Summing up, it must be said that ensuring the integrity of the ice shelves is our primary task.

"The planets of the solar system" - Mars. The Great Red Spot, a giant hurricane in Jupiter's atmosphere. Station "Mir". Neptune. Mir station is above the waters The Pacific... The sun. Mercury and Earth. The Martian year lasts 687 Earth days. Pluto. The third largest planet from the Sun Solar system... Pluto is the smallest of the major planets in the solar system.

"Minor planets" - The Moon's own thermal radiation is negligible. Venus. Atmosphere and water on Mars. Mercury has a magnetic field. The distance of Mercury from Earth is from 82 to 217 million km. Dimensions, shape and mass of Mercury. The atmosphere and physical fields on Mercury. The highest peak of Venus, Mount Maxwell, is 12 km high.

"Giant Planets" - Involvement in the general conversation of students in the class. Later they saw that Saturn has not one ring, not three, but more. The brightest B ring is medium, and the C ring is very faint. Moons of Jupiter. Uranus. The flattened ball is "put on" a bright, very large ring. Pluto has a satellite. Jupiter is the largest of all the planets in the solar system.

"Geography Grade 6 Glaciers" - Classification of glaciers. Glacier Peroto Moreno (Argentina). Can glaciers form in our area now? Iceberg Ice Shelf. Mountain-cover glaciers. The whole area from which the river collects water? How is interstratal water formed? What is the largest lake in terms of area? Monument to those who died as a result of the Kolka glacier descent.

"Formation of planets" - Calcium. The Eagle Nebula. The bulk of the protoplanetary disk leaves the solar system. "Catastrophic" hypotheses. Magnesium. The emergence of planets. Magnesium silicates, iron and nickel. Let's save the Earth as we got it! Formation of planets. The Horsehead Nebula is part of a dark dust cloud.

"Planet of knowledge textbooks" - " art", 1-4 grade. UMK for primary school... "Russian language", grades 2-4. Training sheets. Cognitive activity... Textbooks; workbooks; didactic and teaching aids... Creative tasks. Qualitative assignments. Project activities(Grade 2). The unity of approaches to the organization of educational and extracurricular activities.

The most unique, famous glaciers.

The glacier is approximately 62 km long and is the longest glacier in the world outside the polar regions. The glacier is located in the Gilgit-Baltistan region of Pakistan. Baltoro is surrounded by the Karakorum mountains and is located between the Baltoro Muztag ridge from the north and the Masherbrum ridge from the south, the highest mountain in this region is K2 (8611 m). The lower part of the glacier is located at an altitude of 3400 m above sea level, followed by the melting zone of the glacier, which gives rise to the Biafo River.

Antarctica concentrates the largest number ice, and, therefore, reserves fresh water on the planet. The maximum ice thickness on the continent is 4800 meters, the average ice thickness covering the continent is 2600 meters. Moreover, in the central part of Antarctica, the ice thickness is greater, and less towards the coast. Ice flows from the continent into the ocean. When the ice reaches the ocean, it breaks off in large pieces called icebergs.
The volume of glaciers is 30,000,000 square kilometers, which is 90% of all ice on the planet.

The Kilimanjaro Glacier is not one of the largest glaciers, but its uniqueness is that it is located near the equator in Africa. Mount Kilimanjaro glacier formed 11,700 years ago. Since 1912, it has been observed that the glacier area has begun to gradually decrease.
By 1987, the area of ​​the glacier, compared with 1912, had decreased by more than 85%.
Now the absolute area of ​​the glacier is less than 2 square meters. km. According to calculations glacier scientists will completely disappear by 2033.

Aletsch glacier

The Aletsch Glacier is the largest glacier in the Alps. Its length is 23 km., The area of ​​the glacier is 123 square kilometers. The glacier includes 3 adjoining small glaciers. The maximum ice depth is 1000 meters. The glacier has been a UNESCO World Heritage Site since 2001 (site number 1037bis).

The Harker Glacier is located on South Georgia Island in the South Atlantic Ocean. The uniqueness of the Harker Glacier is its method of formation. This glacier is a tidal glacier. Discovered in 1901 by a Swedish expedition led by Otto Nordenskjold and Karl Anton Larsen. The glacier is quite stable in its area and volume, although its shape changes over time.

Jostedalsbreen glacier

The Joustedalsbreen Glacier is the largest glacier in continental Europe. The glacier is 60 km long, with an area of ​​about 487 square kilometers. Like most other glaciers in the world, Justedalsbreen is gradually decreasing in size and volume. In 2006, one of the branches of the glacier shrank by 50 meters in a few months.

Vatnajökull glacier

The Vatnajökull glacier is located in Iceland, it is the largest glacier in Europe, so, its area is 8100 square kilometers, the volume of the glacier is estimated at 3100 cubic kilometers. The glacier covers volcanoes; inside the glacier there are caves formed by geysers - hot springs of water. The maximum ice thickness is about 1000 meters.

Hubbard Glacier - Located on the border of Alaska and Canada. The glacier was opened in 1895. The glacier is 122 kilometers long. The glacier abuts against the Yakutat Bay. The height of the ice in the bay reaches 120 meters above sea level, the width of the glacier at the bay ranges from 8 to 15 kilometers, depending on the season.

The Franz Josef Glacier is located in New Zealand. The glacier is 12 kilometers long, opened in 1859. The glacier has phases of increase and decrease, after 2010 it entered an active phase of decrease (retreat).

The Perito Moreno Glacier is located in the southwestern part of the province of Santa Cruz, Argentina.
The length of the glacier is about 30 km, the area of ​​the glacier is 250 km. square. The glacier moves along the slopes of the mountains to Lake Argentino at a speed of about 2 meters per day. Periodically, the glacier overlaps the lake, dividing it into 2 parts. The water in the southern part of the lake due to rivers and streams begins to rise in comparison with northern part... The difference in levels is more than 30 meters, under the influence of water pressure, the isthmus collapses, and water flows rush into the northern part of the lake.

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 Svalbard archipelago, and ranks first in size in the entire Old Continent. Its area is 8200 square kilometers.

Vatnajökull, Iceland

A slightly smaller area - 8100 sq. km - occupies the Vatnaekul glacier in Iceland. This glacier is in second place in Europe. If we take the volume of a 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 occupies an area of ​​487 square kilometers, however, unfortunately, the glacier is decreasing 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, has been declared a UNESCO World Heritage Site.

Schneeferner, Germany

The Bavarian Alps region is home to the largest glacier in Germany, which is also 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.

South Patagonian Ice Sheet, Chile and Argentina

Occupies a surface area of ​​16,800 square kilometers of the South Patogon Shield and is considered the largest glacier in South America... Most of its territory is located in Chile - 14,200 sq. 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 Lambert, 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 makes up about 10% of the entire ice continent.

Malaspina, USA

The glacier covers an area of ​​4,275 square kilometers and is 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 6,000 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" is much larger than the most powerful European glaciers.

Ross Ice Shelf

(Antarctica)

As you know, the great navigator Cook never managed to reach the shores of Antarctica. Only almost half a century after his voyage, the ships of the Russian expedition Bellingshausen and Lazarev managed to approach the coast of the southern continent in two places. And twenty years later, in 1840, the famous polar explorer, discoverer of the North Magnetic Pole, James Clark Ross, went to Antarctica to try to discover, this time, its southern counterpart.

And although he did not manage to visit the South Magnetic Pole, the brave captain made many important geographical discoveries, and now his name rightfully adorns the map of Antarctica, and more than once.

Ross was the first to go this far south, crossing dangerous floating ice to nearly 80 degrees south latitude... He discovered the largest and most active active volcano in Antarctica - Erebus, put the sea and the island on the map, later named after him, and then tried to go even further south. But a gigantic ice wall, as high as a twenty-story building, cut off vertically into the sea, blocking his path.

"Fighting this obstacle is like trying to swim through the cliffs of Dover," Ross wrote in his diary.

It was the edge of the largest ice shelf in Antarctica, which now also bears the name of the brave English navigator. The ice barrier that stood in his way, the captain named the Victoria Barrier, in honor of his queen. (Now, however, history has restored justice and it appears on the maps as Ross's Ice Barrier.)

The Ross Glacier fills almost entirely the entire southern Ross Sea. From east to west, it stretches for eight hundred kilometers, and cuts into the depths of Antarctica for almost a thousand. In area, it is equal to the island of Madagascar and exceeds the territory of Sweden, Spain or France. The thickness of the triangular ice plate gradually decreases from south to north. Off the coast of Antarctica, it is more than a kilometer, and near the ocean, where its outer edge is cut off by the Ross Ice Barrier, the ice is about two hundred meters thick.

Ice shelves form where continental ice flows descend from the shores of Antarctica into ocean bays. At the same time, they continue to move along the bottom of the continental shelf - the shelf - to a depth of about three hundred meters. Then the icy tongue floats up, merging with neighboring glacial ledges into a single mass, and all this ice mass continues to move until it fills the entire bay.

Going beyond its limits, the glacier loses the protection of the coast, and the waves shaking the huge ice field begin to break off its edges. This is how table icebergs are formed - the floating ice islands of Antarctica. Such icebergs are much larger than the ice mountains that break away from the glaciers of Svalbard or Greenland. Sometimes their size is simply amazing. For example, in the winter of 2000, New Zealand sailors noticed an ice mass the size of the island of Jamaica south of their shores!

And the largest table iceberg had an area of ​​more than thirty thousand square kilometers, that is, it was larger than Sicily. Such ice islands usually rise thirty to forty meters above the water, and go two hundred meters or more in depth.

The Ross Ice Shelf is fed by glaciers flowing from the slopes of the mountains of Queen Maud Land and from the Transantarctic Ridge. Rising four kilometers above sea level, these mighty mountain systems give rise to several glacial streams that merge into a single ice field on the coast of the Ross Sea. It is slowly but steadily moving towards the open sea at a speed of up to a kilometer per year. As you move, the ice melts from below, and cold bottom currents are formed, directed northward towards the ocean.

The outer edge of the glacier, the very Ross Barrier, is indeed vaguely reminiscent of the chalk cliffs of Dover, so close to the hearts of English sailors. It is here, under the influence of storms, that the two-hundred-meter thickness of the glacier cracks and the ice islands-icebergs break off. Their number in Antarctica, in comparison with Arctic waters, is enormous. Sometimes from the deck of a ship one can see up to a thousand floating ice blocks at the same time.

However, the formation of cracks and the separation of pieces of the ice field are characteristic only for the edge zone of the glacier. In general, there are no cracks on the ice shelves, and it is much easier to move along them than along continental ice Antarctica. It is no coincidence that most of the expeditions to the South Pole began from the Ross Sea.

This area attracted researchers also by the fact that a whole bunch of attractions worthy of the attention of scientists are concentrated here, in particular, the active volcano Erebus, the reflections of the fire above which turned it into a kind of beacon for everyone who swims in the Ross Sea. And nearby, in Victoria Land, was the South Magnetic Pole. Now its location has shifted to the north, and the pole point is in the ocean, near the coast of Antarctica.

The discovery and study of the magnetic pole on the southern continent is associated with the name of the famous Australian polar explorer Mawson, a member of the British Antarctic expedition Shackleton. He visited there while Shackleton, with three companions, tried to storm South Pole... The attempt of the Englishman was unsuccessful, and the pole was submitted to people only four years later, when the Norwegian Amundsen and the Scot Scotg reached it. Mawson, in the absence of the leader of the expedition, wasted no time and managed, together with two other researchers, to visit the point that had attracted scientists for half a century since the time of Ross. The same Mawson with two satellites was the first to conquer the formidable volcano Erebus, which rises four kilometers above eternal ice Antarctica.

It happened in 1908. Scientists climbed to the top of the fire-breathing mountain in three days and examined all three of its craters. The largest of them was three hundred meters deep and eight hundred meters in diameter. At the bottom of it, lava, fire and smoke escaped from several holes, and there was a liquid lava lake. Combined with severe frost and wind, this made staying at the summit "not the most comfortable experience," according to Mawson.

It should be noted that the lava lake of Erebus, which still exists today, is the rarest phenomenon in the world of volcanoes. In addition to the Antarctic giant, long-term lakes of liquid lava have been noted only in the crater of the Kilauea volcano in the Hawaiian Islands and in the Nyi Ragongo crater in Africa. However, the lake of fire among eternal snow and ice makes, without a doubt, a stronger impression.

Enough work in the Ross Sea, not only geologists and magnetologists. Biologists also consider this area to be one of the most interesting in Antarctica. Despite the harsh climate, life is in full swing at the edge of the ice shelf. Cold currents, carrying oxygen-rich water, promote the development of marine microorganisms and algae, which in turn attract numerous schools of tiny shrimps and a variety of fish. Baleen whales swim to the Ross Sea for shrimps. And fish are coveted food for seals and seabirds. By the way, it was Ross who discovered here in his time a new, fourth species of Antarctic seals. It was named the Ross seal.

However, birds far outnumber whales and pinnipeds. Tens of thousands of gulls, petrels, sea martins and skuas nest on the rocks at the edges of the ice barrier. The latter often fly into the interior of the continent. American winterers observed them even at the South Pole.

But the most numerous inhabitants of Antarctica are, of course, penguins. The population of their colonies reaches several hundred thousand birds. There are several species of penguins, like seals: the little Hell-eating penguins, the larger ones - the royal ones, and the largest - the emperor ones. Emperor penguins living only in two places of Antarctica are especially interesting. These large birds sometimes weigh up to eighty kilograms and have tremendous strength. There was a case when five sailors could not keep one such "emperor".

The female penguin lays a single egg directly on the ice, after which the father of the family takes care of it. He lays the egg on his paws and covers it with a fold of fat hanging down the bottom of the body. After that, the male does not leave his place for three months and does not eat, incubating the offspring, and the female recovers during this time, fishing in coastal waters. Then the parents switch roles.

Penguins have adapted well to life in the harsh conditions of the Ross Sea region, where they have only one dangerous enemy - the leopard sea. But these predatory seals are relatively few in Antarctic waters, and penguin colonies thrive despite Antarctica's rugged climate.

The curiosity and friendly disposition of these unusual birds pretty much brightens up the life of polar explorers on the icy continent. The penguins' curiosity knows no bounds. It is enough, for example, to turn on the tape recorder, as a dozen feathered "music lovers" gather around a person to listen to music.

At one time, Ross's Ice Barrier did not allow the south sailing ships, and even now its wall is "too tough" even for modern icebreakers. However, on the other hand, it was from here, from the Whale Bay (the only place on the barrier where its height drops to seven meters), that he began his victorious campaign to the Amudsen Pole. Expeditions of the famous polar explorers Shackleton, Mawson, Charcot, Drygalsky and others. And now there is an American polar station McMurdo.

And if we talk about the most studied area of ​​Antarctica, the southernmost continent, then, without a doubt, this is the area of ​​the Ross Sea - a huge body of water stretching almost to the pole, covered with a white shell of the Earth's most extensive glacier - the Ross Ice Shelf.