Unique Earth: The Essence of Water | Full Documentary

The blue planet. The earth owes its name to water. It was in the oceans that life originated. Only water is found on earth in three states. Liquid, solid and gaseous. Water shapes landscapes. Deep canyons cut into the rock by waterfalls and rivers, as well as icy polar landscapes. Hydrogen and oxygen combine to form H2O. Water. One of the world's smallest molecules. Water is the essence of life. Water is mankind's most precious good. 70% of the earth's surface is covered with liquid water. Water makes our earth unique. Virtually no other substance has been as well researched, yet still poses so many questions. Scientists worldwide are striving to unlock the secrets of water. Some 700 islands and countless coral reefs make up the Bahamas, a natural landscape and island paradise in the Atlantic. Here the sea is often only a few meters deep. But in many places behind the coral reefs the seabed plunges steeply to a depth of up to four kilometers. Great Abaco is one of the biggest islands in the north of the Bahamas. The two marine biologists Tom Iliff and Uli Kunz are on their way to a mysterious location in its interior. Just behind the pine forests on Abaco island lies a hidden world. The entrance is well concealed and for good reason. Diving here is dangerous and only trained cave divers are allowed into the water. Brian Kaycook probably knows the cave world of the Bahamas better than anyone else. He will guide the two marine researchers on their expedition. I'm going into places that scientists have not normally gone. So there's a significant number of exploration cave divers who are going in and studying these caves, but very few of them are scientists. So I want to go in, I want to see what this environment is like and what animals are living there. A narrow fissure leads into the underworld. At first the men dive through a layer of fresh water. The lifeline is the divers life insurance. Only with its help will they be able to find their way back. The cave system runs for hundreds of kilometers through large parts of the island world of the Bahamas. Whole areas are still completely unexplored, a challenge for scientists. The researchers have passed right through the fresh water layer. Down here they're swimming in pure seawater. Stalactites thousands of years old form a fascinating world of their own. Progress is slow. The men know that one wrong kick with their fins could destroy the formations. All these structures formed when the caves were still dry. In the course of time the most bizarre shapes emerged. They're conserved by clear water which is extremely low in oxygen. This is a time capsule. Fossils thousands of years old are found here again and again. But how was such a unique underwater world able to form at all? During the ice age glaciers spread. Worldwide the sea level fell by up to 130 meters. In the Bahamas too. Large parts of the reef which forms the island's bedrock dried out. Rain eroded cracks in the limestone and in the course of time an extensive cave network was created. Collapsed cave ceilings provide entrances to the underwater world. Towards the end of the ice age the sea level rose again flooding the caves and creating the characteristic blue holes. Most blue holes have one thing in common. Two aquatic worlds fresh water and sea water located one above the other. The fresh water here is like an iceberg. We think of an iceberg floating out in the ocean. Below our feet is a liquid iceberg. It's the fresh water and so being lighter it floats on the heavier salt water underneath. So there's basically an extent of the ocean penetrating in and under every single island in the Bahamas. Today there are vast numbers of these circular holes here. Many are interconnected underground. Here in Sawmill sink the researchers are swimming through a layer containing toxic hydrogen sulfide. A gas which in high concentrations is dangerous for divers. Directly beneath is a magical divide called a halocline. Fresh water lies above it and sea water which is heavier lies beneath it. The divide seems paper thin yet it separates the two aquatic worlds perfectly. But why can't fish and other organisms simply swim through the halocline? Well sea water is saltier than a fish and salt attracts water. As a result the fish constantly loses water through its skin so it has to drink. But every mouthful of water also contains salt and that has to be expelled again via the fish's gills. A complex procedure. In contrast a fish living above the halocline is saltier than its environment. So water permanently threatens to flood its body. It doesn't drink yet it still has to expel the water which penetrates through its skin. That's why the two will never meet even though they live in the same cave. In this confined space a laboratory of evolution has emerged. Remipedes for instance are found only in a few places on our planet. Indeed these remarkable creatures were not discovered until the late 1970s. Tom Illiff is the expert on this animal group. Remipedes live in salt water so they can only be brought to the surface through the freshwater layer in sealed tubes. After a good two hours the excursion into the labyrinth of caves is over. But the day's work isn't over for the scientists. They want to examine their valuable samples straight away. Remipedes look like centipedes but they belong to the crustacean family. They could even be a primeval form of crab. In their dark habitat during the course of evolution they have lost their eyes. Worldwide there are countless species of remipede. Tom Illiff has been studying these creatures for over 20 years. Remipedes are a really intriguing animal. Their distribution on both sides of the Atlantic suggests that they've been living in caves since the formation of the Atlantic and actually predate the extinction of the dinosaurs. Maybe if dinosaurs lived in caves they'd be around too. The tiny crustaceans have been around from time immemorial but because of their hidden way of life they were only discovered very late. The creatures are helping scientists to trace the Earth's development. They are one of many pieces of the puzzle. Today the Atlantic is a huge ocean which separates continents. The Earth's crust is permanently moving, something that can be observed particularly well in Iceland. This North Atlantic island lies precisely on a fissure between two continental plates. Here the Eurasian and the North American tectonic plates are forced apart. Only in Iceland is it possible to dive between the continents. Glacier water fills the fissures creating a special habitat and a unique diving location. With one hand in America so to speak and the other in Europe. Millions of years ago the whole Atlantic was just such a fissure between the continents. Deep in the bowels of the Earth enormous forces are at work permanently reshaping our planet. In the Atlantic they are causing the seabed to grow. Eruptions occur regularly sculpting the mid-ocean ridge, the biggest mountain range on Earth. More than 60,000 kilometers in length it stretches right around the globe. Iceland is part of this mountain range. In the north of the island biologist Uli Kunz is on his way to Stryton, a so-called white smoker, a hydrothermal spring on the seabed. Normally such vents only occur in the depths of the ocean but on Iceland they can be found as little as 15 meters from the surface. Thus a totally separate ecosystem has evolved. The vents are a window on the Earth's interior. Minerals and hot water bubble up. Down here things are still the way they must have been billions of years ago. Scientists suspect that at one time hydrothermal springs gave rise to life itself. Conditions were ideal. There was water and energy. In the cracks and crevices of the vents the building blocks of life were able to come together. At some time or other the first cell drifted out into the sea. In the course of three billion years it resulted in the enormous diversity which surrounds us today. Species emerge and become extinct and even today no life can exist without water. But why is there water on Earth at all? Astronomers suspect that water was brought to the Earth billions of years ago by meteorites. Our planet is struck regularly by meteorites even today. Most of the impacts go unnoticed. Others hit the headlines. In 2013 a projectile from outer space exploded in the Urals in Russia. In 2016 researchers discovered a 30-ton meteorite in Argentina. And in Michigan in 2018 the sky was lit by a ball of fire caused by a meteorite. But some of these meteorites have quite a bit of water. You know to the tune of 20 percent of the mass of the rock is made up of water with clays and hydrated minerals. And this material was certainly transported to the early Earth several billion years ago and could have contributed a significant fraction of the Earth's water that we have today. In the early days of our solar system countless lumps of rock sailed through space. The young Earth too was exposed to a veritable bombardment. Astrobiologist Daniel Glavin believes that fragments of meteorites contain messages from the early days of our solar system. He breaks down cosmic rock into its components. Is it possible that not only water but also the building blocks of life came to us from Meteorites are actually very complex. They really hold in all the secrets from the early solar system. Where the water came from. Where the organic compounds came from. This meteorite I'm holding here in the test tube has over a hundred different amino acids. A hundred. Life is made up of 20. These are very chemically complex samples which makes it so exciting. It's actually the reason I love my job so much. Clear indications that water came to us from outer space but not solid proof. That's what NASA now hopes to provide. In September 2016 a rocket launched the sampling spacecraft OSIRIS-REx. Its destination the asteroid Bennu. A lump of rock measuring 500 meters across. OSIRIS-REx's task is to take samples on Bennu. The asteroid is also interesting for another reason. Its orbit will take Bennu dangerously close to the earth but not for more than a hundred years. The capsule with the samples from Bennu is scheduled to return to earth in 2023. This is a very ancient asteroid. Four and a half billion years old. A frozen time capsule. A fossil from the early solar system. And what I'm hoping to find out is when we have these samples back on earth is to understand for example how much water is in this asteroid. How much asteroids like Bennu could have contributed to the oceans that we have on our earth today. And also whether or not there are any building blocks of life. I'm really excited about looking for those types of organic compounds in these materials. But why is water only found on the earth? After all such projectiles also hit other planets. But mercury for instance is located too close to the sun. So any water evaporates at its equator. Conditions on earth though are ideal. Further out in space too on mars the chances of water existing in liquid form seem good. Three billion years ago there were torrential rivers here. From the volcanic region in the south they flowed into a vast ocean in the north. Over millions of years however most of the water evaporated. Today mars is barren and empty. On the earth however life exploded. Around 10 million species live in the world's oceans alone. Hidden in the depths are countless organisms we know hardly anything about. In the ocean some things are different. Sounds for instance play a special role underwater. Sound is as important for dolphins and other marine creatures as light is for man. But for some time now there has been interference. Countless drilling rigs, ships, sonar equipment and military exercises produce a deafening noise around the clock. Only a few regions in the world are spared at least to some degree. Like the Cook Islands in the south pacific. It's here that the significance of sounds underwater can be studied best. Nan Hauser is a whale researcher. For 30 years now she's been observing whales off the coast of Rarotonga and studying the behavior and communication patterns of these marine mammals. Humpback whales. Every year the period from July to September is whale season in the south pacific. The animals spend several months in the warm water mating and rearing their young. During this time humpback whales don't feed. They live solely from their fat reserves. Using a hydrophone, an underwater microphone, Nan can even detect whales a considerable distance away. We got a singer! Male humpback whales sometimes sing for hours on end. I can hear. Scientists still have only a partial understanding of whale songs. Good morning. The songs are made up of several verses and each whale population sings a slightly different melody. This enables researchers to determine which region a whale comes from. It seems however that the different songs are mixed. In Rarotonga, Nan records new songs time and again. We have recorded whales that are teaching other whales the song which is fascinating and sometimes we'll have a song and we think that's the song for the Cook Islands for the season and then another whale will come in and it will sing another song. A totally different song and then a few days later the whales here will have incorporated a phrase of that song into their song. During the whale season Nan spends many hours each day on the water. Nevertheless, as a rule, only brief observations from the boat are possible. Diving into their habitat is far more rewarding, but it has to be done without breathing equipment because the noise would irritate the animals. The whales tolerate free divers near them. This makes unique observations possible, but only for a short time. On average humpback whales spend 20 minutes in the depths, impossible for a diver without oxygen tank. Consequently, marine biologists are also dependent on indirect clues for their research. For instance, as the animals surge through the water, flaps of skin are left behind. For Nan Hauser, such scraps are a source of important information. They are a kind of whale fingerprint. We look at the genetics and we can tell whether it's a male or female, the species, what clade it's from. We're trying to figure out how to use the end of the DNA strand, the telomeres, to age the animal. We look at blue carbons, stable isotopes, microbiology, everything just from a little piece of skin. Pretty cool. After the mating season, the whales set off on their great journey to the Antarctic. Like the water itself, marine organisms are also constantly in motion. Some migrate of their own accord, others are carried by the current. Krill. In the Antarctic, these tiny crustaceans form gigantic shoals, and they attract humpback whales. Every year, the whales travel more than 10,000 kilometers to and fro between their winter and summer quarters. The big ocean currents distribute warmth, food and energy, and thus control all life in the seas. At the equator, the sun heats up the ocean. The warm water drifts to the poles, where it cools and sinks into the depths. It flows back as a deep current, and the cycle can begin again. Wherever the ocean currents transport nutrients to the surface, life concentrates. This movement is driven by salt and temperature differences. We're talking about a global conveyor belt, but we still don't know precisely how it functions, or how, for example, it reacts to changes in the water temperature. Now, an international research team plans to solve the riddle. With aircraft, airships and numerous research vessels, they are staging a very special search. Today, they are focusing on an area of the Baltic Sea, southwest of the Danish island of Bornholm. From the air, the researchers can scan the surface of the water, because what they are looking for is transient. The emphasis is not on the major ocean currents, but on small eddies. They were only discovered a few years ago, and scientists suspect that they play a major role with regard to main coherences in the ocean. Expedition leader Burkhard Baschek wants to determine the connection between small eddies and major currents. We've worked for years to put us in a position where today we can go out and survey eddies. We've invested so much effort and are really excited. Naturally, we'll try to get the very best results. We've prepared everything as best we could, so we're absolutely delighted. Satellite pictures have helped us gain a better understanding of our blue planet. The major ocean currents are also clearly visible from space. For a long time, though, small eddies could not be detected. It's only now, by combining various technologies, that researchers have managed to study these currents more closely. And they are astonished at how often small eddies occur in the ocean. Oceanic eddies range in diameter from 100 meters to three or four kilometers, so they're relatively small in comparison with the other ocean currents. And they're found worldwide. Their special feature is that they're short-lived. Some exist for as little as 12 hours. They rotate very quickly and dissipate just as fast, so we have to be quick to measure them. First of all, in the early morning, the motor glider surveys the research zone in the Baltic. Its task is to locate eddies. The airship also scans the surface with special cameras. Burkhardt-Baschek coordinates the search. The airship has one decisive advantage for the researchers. If something interesting has been discovered, it can park for hours over the water and enable the surface to be surveyed in detail. Cardinal, here's the airship. We've found an eddy. The decisive signal. Baschek gives the coordinates through to the research ships. The structure in the water can even be seen with the naked eye. A distinct front runs right across the surface. So where does this structure come from? The crew on board the research vessel are lowering the troll, as it's known, into the water. The device is packed with sensors, which provide data on the density and the oxygen content of the water. In the water, the troll bobs up and down. Since the eddy is constantly changing and moving, the measuring equipment also has to be mobile. The data are transmitted immediately to the airship, where a thermal image shows what's happening in the water. The current transports cold water from below up to the surface. Enormous energies are at play here. The great thing is that for the first time ever we were able to observe an eddy from its formation to its dissipation. So today we've achieved a totally new level of data accuracy. The eddies are of decisive importance to life in the ocean, because along with the cold water, nutrients are brought up from the depths. Comprising a broad range of tiny algae, unicellular creatures and bacteria, they're a launch pad for life. Major ocean currents and small eddies are a heat pump for our planet, and they also influence conditions on land. It's thanks to the Gulf Stream that lush forests grow in our latitudes. Deciduous forests need a moderate climate and water. All trees have the same problem. Even if they are standing in water, the water still has to be transported from the roots up to the leaves. With a beech tree, that can mean a good 40 meters. It all begins in the ground. If the roots are drier than the surrounding earth, water penetrates automatically. Water and nutrients are taken into the interior of the tree via countless thin root hairs. It's at this point already that some pollutants are broken down. The water then diffuses further into the tree's xylem condits. It's then transported up in these highly specialized pipelines. Beech trees achieve a speed of up to 6 meters an hour. The water is sucked up by capillary action, because in narrow tubes, liquids rise automatically. But that is still not enough to transport water to the treetop. This takes place by means of transpiration pull. Every molecule that escapes into the air draws a new molecule from the soil. In this way, there is a constant flow of water through every tree. A highly effective pump, the forest creates its own moist climate. Here, one in every three raindrops becomes drinking water. But most of the water rises up again via the trees, evaporates and forms clouds. They look as light as a feather. But fair weather clouds, known as cumulus, can easily be one cubic kilometer in size and weigh thousands of tons, as much as five houses. The more water a cloud contains, the heavier it gets, until eventually rain falls. The volume of precipitation on Earth is distributed most unevenly, and determines whether a region enjoys abundant growth or suffers from drought. The clouds contain only a fraction of our freshwater reserves. But what determines whether clouds simply dissipate, or rain actually falls? Eberhard Burdenschatz wants to find out. He has devoted his entire life as a researcher to clouds. In order to study them, he pays regular visits to Germany's highest mountain, the Zugspitze. Located at an altitude of 2,600 meters, the Schneefernerhaus, a former hotel, is Germany's highest research station. It's an ideal place for cloud research. I simply want to understand exactly how rain is formed. We all know that rain does fall, and we also know a great deal about it. But can we really predict from the dynamics when it will rain? How a cloud develops? Basic questions present themselves. Can I improve weather forecasting? Can I say when it will rain? Can I produce a weather report that is reliable for longer periods, not just for a day, but also for a week? Can I forecast the climate? The two researchers are on the lookout for clouds. What they are interested in takes place constantly in every cloud, invisible, however, to the human eye. Tiny droplets of water are driven to and fro. They evaporate, collide, and sometimes grow to form raindrops. For that to happen, droplets need to collide. Droplets have to find one another. That's a nice way of putting it. So droplets have to find one another, not just two, but millions of them, in order to form one raindrop. That is how rain forms. The researchers will observe this process. They want to see how raindrops form in a cloud. So far, no one has managed that. What they plan is only possible with the help of state-of-the-art technology. But the clouds also have to play along. In the late evening, the conditions are ideal. Okay, we'll run the motors now. Okay, I'm ready. Releasing in three, two, one. A powerful laser makes the tiny droplets visible. The equipment functions like a gigantic flash gun. Evaluation is still underway, but the data will probably provide the answer to one of the greatest mysteries of cloud research. And done. Someone who understands how rain forms could, in a subsequent step, try to influence the weather. The country which gets the first cloud has the first claim on it. Just imagine if we were able to make our clouds produce rain or not, because that's just as important. Let's say that our farmers want to bring in the harvest, so all the clouds are sent to Poland, causing massive downpours there. And that's what scares me. The idea of us focusing not on water on the ground, but on watering clouds. And water is mankind's most precious good. Water is the elixir of life. Without water in its liquid form, life as we know it would be inconceivable. We drink it, and it serves as a habitat. Around half of all species of fish live in fresh water. We are all more than familiar with the properties of water. Yet H2O often behaves differently from any other substance. For example, when it freezes. When a lake freezes over, the ice floats on the surface. So we have the solid form of water on top and the liquid form underneath. The reason why ice is lighter than water is because water has its maximum density as a liquid. That is a curious property, but it explains why life is able to exist under the ice. The layer of ice acts as an insulation and prevents the water beneath it from freezing. In Lake Baikal, even a species of seal is able to survive under the ice. It's the only seal that occurs solely in fresh water. Beneath the ice life continues, even though in winter Lake Baikal is frozen for months on end. Scientists have been studying the characteristics of water for centuries, and they're surprised time and time again. Probably the most mysterious water in the world lies hidden in South Africa. The Moab Kotsong mine is one of the biggest in the country. It has served as a source of uranium and gold for more than a hundred years. Outdated and modern technology often collide. Accidents occur here time and again. It's not gold that Errol Kaysen and his team are interested in. They are looking for water. Water that is millions, perhaps even billions of years old. This is the fastest and longest mine lift in the world. The final station is more than three kilometers underground. The deeper the men go, the hotter it gets. The mine cage hurtles down at a speed of almost 70 kilometers an hour. We're hoping that we'll find some water down there. They're getting pretty close to the fracture zone now, so this is now the best chance that we'll actually find water in that cavity down there. But we still have about 20 meters left to do before we actually hit where the fracture was with the previous holes. So anything can happen. If it weren't for gold mining, the researchers would never have been able to explore this extreme and inhospitable region. Spreading out far below the surface here is virtually a medium-sized town. The researchers travel on by mine train. The drilling site has been carefully chosen because only a few years ago the earth shook here. The scientists want to drill precisely into the fault zone. They suspect that somehow there is a link between the earthquake, water and microbes that live underground. Rock this old is only found in a few places on earth and hardly anywhere is it accessible to scientists. The ore mined here formed deep in the bowels of the earth nearly three billion years ago. Can life really exist under such conditions? Traces of water are at least a crucial prerequisite. We're drilling four kilometers below surface and from a microbiology standpoint this has also not been done a lot in the past. So as we're going deeper and deeper under the surface the water becomes hotter, water becomes older and any microorganisms that we might find might be more unique, more novel or anything that we haven't seen before. Cooling water is escaping everywhere. It's essential to make sure it doesn't contaminate the samples. If the scientists' calculations are correct they are very close to the fault which caused the earthquake. This is something they've worked towards for many months. One core drill after another is removed from the rock. If the samples really do contain life it must be able to cope with the most extreme conditions. Heat and radiation, immense pressure and eternal darkness, no oxygen and virtually no nutrients. But life finds the most astonishing solutions. Some of the microorganisms down here in the subsurface might take even a thousand years to go from one cell to two cells and this is only one of the ways that they have managed to survive down here. Back in the laboratory biologist Errol Kaysen gets straight down to work. He has specialised in finding creatures in the most impossible places. He expects to discover microbes which are minute unicellular organisms. But he finds something far bigger. Remarkable worms around half a millimetre in size, huge in comparison to protozoa. It's living, it's breeding. How amazing it is that life can actually occur and survive in really weird circumstances. That has definitely changed my perspective regarding what is possible and what we've previously thought is impossible. It would apparently appear that nothing is impossible when life is concerned. Organisms which inhabit the depths live in slow motion but all around them evolution continued. For a long time life only existed in water but at some point it took its first step onto land. The Tiktaalik was a fish that walked on fins. That was nearly 400 million years ago but since then life has conquered every corner of the globe. Whether we're talking about tropical rainforests or inhospitable deserts, the sole prerequisite for life is the presence of water. There is life in the eternal ice of the Antarctic just as there is in the polar regions of the north. A large proportion of the earth's freshwater reserves are frozen solid at the poles. Scientists at the Polish research station on Spitzbergen are studying the Arctic. Global warming is having a particular impact on this region. When the men are out and about they always carry a gun. Not because of the Arctic foxes but on account of the polar bears whose trails lead right past their station. The landscape here is amazing. The northern lights are visible right through to spring. The scientists are preparing for a very special expedition. They are going to descend into a glacier and examine its heart, so to speak, from the inside. It's very important to understand how the water behaves inside the glacier because this affects all the dynamics of the glacier and up to now it's a kind of black magic box and we only have theories about what is going on inside and the only way to verify the theory and to really know actually really what's going on inside is to go inside this cave system. The men set off in the early morning. Their destination, the Hanspring glacier, is only about two kilometres away. The landscape of snow and ice they travel through consists of frozen fresh water. But when the ice masses here melt they flow into the ocean and cause the sea level to rise. Consequently, the cycle of salt water and seawater is extremely coherent. Last autumn, Leo Decaux marked the entrance to the glacier with a metal pole. Since then, a lot of new snow has fallen. Even so, beneath it there must be a way in. So the men have to dig. Success! The team have found the glacial mill or moulin, a natural entrance to the glacier. The men descend metre by metre. Little by little, the shaft has been carved out of the ice by meltwater and rock. The ice crystals consist of H2O, frozen water molecules, and yet each crystal is unique because the structural possibilities for its composition are infinite. The men are well secured. It can mean the difference between life and death. Especially here, in the upper region of the glacier, where the ice is younger and contains lots of air. The team now abseil for a good 70 metres. At regular intervals, Leo installs a sensor in the ice to record the pressure and temperature, as well as the movement of the glacier. The measuring devices will remain here for the next few months. Leo will not be able to return and evaluate the results until next autumn. Do you hear that? Just be quiet for a second. Listen. Yeah, that's water. This is the water, yeah. That's beautiful. If it were a little later in the year, the men could be surprised at any time in these passages by a river of meltwater. In summer, water surges into the depths here. It's only in spring and autumn that the researchers are able to advance so far into the glacier. The weather conditions are right and the ice has the right solidity. The men have finally reached the base of the glacier. They've been on the go now for a good six hours. Towering up all around them are millions of tonnes of ice. In several stages, they've covered a difference in height of over 200 metres. The glacier doesn't lie on the bedrock. Between the glacier sole and the rock is a narrow passage. In some places, it's big enough to walk in. In others, it's only a few centimetres high. The ice might look stable, but the glacier is constantly moving. Actually, the fact that we have this water flowing that you can hear right now, it's just coming and lubricates this interface between the bottom of the glacier and the rock, which is like very hard to move on it. But it's actually on the water, so it's very easy to slide. And the more water you will have at this interface, ice and rocks, the fastest the glacier will go. From the outside, the glacier looks like a compact ice mass. But in reality, it's permeated by holes and channels. The meltwater cuts tunnels in the ice. In summer in particular, water plunges into the depths through these moulins, as they are known. The water collects at the base and the whole glacier slides towards the sea, as if it were on a film of lubricant. On the coast, huge ice masses then shear off and cause the sea level to rise. Leo wants to measure this glacial movement with his sensors, exactly where it takes place. So far, scientists know astonishingly little about processes deep in the interior of a glacier. Hot steam and ice are a dangerous mix. But Leo wants to fix his sensor as securely as possible. It's the only way of ensuring he'll be able to find it again in several months' time. The data will enable him to determine how much water has flowed through in the summer months. Piece by piece, the researchers are putting a picture together, which they hope will answer important questions. How quickly are the glaciers melting? And what consequences will this have for the entire ecosystem in the Arctic? The glacier extends as far as the coast. Here, it's only a few meters thick. A strenuous and dangerous expedition has come to an end. It will take years to evaluate the findings. Glaciers, oceans, rivers and clouds are all part of the eternal water cycle. And all life depends on water.