Antarctica melt: a trip to the “glaciers of the afterlife”

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The pictures appear dark at first sight

The sediments pass from in front of the imaging device installed in the wedge, the remotely controlled yellow-colored submarine, which is slowly and cautiously moving forward under the ice.

But the water soon returns to its clarity.

The place where the submarine is operating is located under 600 meters of ice, off one of the world’s most vulnerable glaciers.

Suddenly, a dark shadow looms from the top, which is an icy slope covered in dust.

The scenery does not seem to be of little importance, but it is truly unique in nature. These are the first pictures that capture the borders that were soon changing our world.

The submarine (Aesvin) has reached the point where the warm ocean waters meet the ice wall that represents the outer limit of the mighty Thwits Glacier, the point at which the ice begins to melt.

Image source
British Antarctic Survey

The “afterlife” glacier

Scholars describe the glaciers Thwits as “the most important glacier in the world”, “the most exposed to danger”, and even “the glacier afterlife”.

The size of this glacier is enormous, its area roughly the size of Britain.

This glacier is now responsible for 4 percent of the annual sea level rise, which is a tremendous figure for one glacier, and satellite imagery shows it is melting at an accelerating rate.

The Thwits Glacier contains enough water to raise the sea level by more than half a meter.

The Thwits Glacier is located in the middle of the western ice sheet of Antarctica, and is a huge basin of ice that, when melting, can raise the sea level by another three meters.

However, no one has attempted an extensive scientific survey of this important glacier – until this year.

The ISVIN Submarine Operating Team, together with about 40 scientists, make up The Twits International Glacier Cooperative, A 5-year British-American joint venture with a cost of $ 50 million.

This project represents the largest field scientific program in the history of Antarctica studies – and the most complex.

You may be surprised at the scarcity of available information on this important glacier. I was surprised, personally, when the research team invited me to cover his activities.

But I soon found out why I was trying to get to the place myself.

The flight that was supposed to take me from New Zealand to the McMurdo Research Station, the main American research station in Antarctica, has been delayed due to snowfall on the icy airport runway.

These were the first obstacles and obstacles that faced me on this trip.

And I learned that science teams need weeks to reach only their field locations.

At one stage of the project, the work team nearly canceled the planned research for the whole season because the storms caused the cancellation of all flights between the western continent and the McMurdo station for 17 consecutive days.

Image caption

The writer is in Antarctica

How important are thwits?

The western side of Antarctica is the most difficult part of the world’s most vulnerable continent.

The Thwits Glacier is isolated and remote even by the standards of this remote continent, as it is 1,600 km from the nearest research point.

Only 4 people previously reached the front edge of the glacier, and those were the vanguard of the working group there now.

But it is very important and vital to understand what is happening there so that scientists can predict future sea level rise.

It is worth noting that Antarctica contains 90 percent of the fresh water in the world, and 80 percent of the ice containing this water is located in the eastern part of the continent.

Image caption

Ice of Antarctica

The ice of the eastern part of the continent is distinguished by its thickness, which exceeds an average of 1.6 km, but is located on high ground and only turns very slowly to the sea.

And a part of it is millions of years old.

However, the situation is very different in the western part of the continent, as this part is smaller in size, although vast though, and it is subject to change much more than its eastern reserve.

Unlike the eastern part, the ice of the western part is not found at great heights, but rather does not exceed sea level. Were it not for the presence of ice, the eastern part would have turned into a part of the deep ocean with only isolated islands.

I stayed in the Antarctic Antarctica for 5 weeks before I could get on the small red plane belonging to the British mission to Antarctica that took me to the front face of the glacier.

Where I will join the research team camp in the place known as the “grounding area.”

This camp on the ice is located at the meeting point of the glacier with the ocean water, and the scientists residing there perform the most ambitious missions ever.

The task is to dig into the ice about half a mile deep at the point where the glacier begins to float.

No one has ever done this in a glacier of such magnitude and speed of movement.

The research team will use the hole in the ice to reach the sea water that melts the glacier, in order to find its source and why it attacked the Ice River so severely.

But researchers do not have time.

The frequent delays and obstacles have reduced the time available to them, and there are only a few weeks of the Antarctic summer season before the weather gets very bad.

As the drilling team sets up their equipment, I help them conduct a seismic survey of the land beneath the glacier.

Dr. Kia Riverman, a glacier scholar at the University of Oregon in the United States, is drilling in the snow using a large steel drill and detonating a number of small IEDs.

For the rest of us, we start digging in the ice to install electronic sensors that sense the echo of the explosion coming from the rocky layer at the bottom of the hole that Riverman digs through the layers of water and ice.

Image source
David Vaughan

Image caption

The front face of the Thwits River

Thwaites perch on the sea floor

The main cause of concern for scientists about the Thwits Glacier lies in the Milan seabed that perch on it.

This means that the glacier gets thicker as we get on land.

The base of the glacier lies about one mile below sea level at the deepest point, and there is a full mile of ice above that.

What appears to be happening is that the deep, warm ocean waters run towards the coast and to the front of the glacier and melt.

The more the glacier recedes, the more ice will be exposed to warm water.

The process is somewhat similar to cutting slices from the sharp side of a triangle of cheese.

The surface area of ​​each successive slice is greater than the previous one, which exposes more ice to warm water to melt.

This is not the only effect.

Because of gravity, the ice tends toward flatness, and as the front edge of the glacier melts, the massive reservoir of ice behind it rushes forward.

“He wants the ice to rush out,” said Dr. Riverman, adding that the higher the foot of the ice the higher the glacier tends to rush.

In other words, the more the glacier melts, the faster the ice will burst it.

“The fear is that these processes will accelerate,” said the scientist. “There is a cycle back, or a vicious circle.”

Image caption

Kia Riverman and Lizzy Klein are bored in the ice

Carrying out scientific research projects of this magnitude and in such a difficult environment requires more than just transporting a few scientists to a remote area, but it also requires the transfer of many specialized equipment and tens of thousands of tons of fuel in addition to tents, accommodation and food requirements.

I stayed in the icy environment for one month, but some scientists stay in the camp for two months or more.

The process of transporting scientists and some of the equipment they needed to the main induction camp in the middle of the continent’s ice sheet required more than 12 flights by the Hercules squadron of sled transport planes belonging to the US Antarctic Program.

From the main desertification camp, scientists and equipment are transported on smaller planes to the field camps hundreds of miles inside the glacier towards the sea.

These distances are so great that the project was forced to establish another camp in the middle of the glacier in order to provide the aircraft with the necessary fuel.

The British mission’s contribution was a “epic” land journey that transported hundreds of tons of fuel and equipment.

Two steamboats designed to sail in the waters floating in the ice from the anchorage in the previous polar summer season near an ice slope located at the edge of the Antarctic Peninsula.

From there, a team of drivers driving ice-powered machines transported the material brought by the two ships over a thousand miles above the ice sheet and through one of the most difficult terrain and the most difficult weather conditions on Earth.

It was an arduous journey, with a top speed of only 10 miles per hour.

Image caption

Ships of equipment and supplies

Ice craters

Scientists in the “grounding area” camp intend to use hot water to drill a hole in the ice.

In order to do this, they need 10,000 liters of water – which means they will have to melt 10 tons of ice.

Everyone participates in this process with wiping, and sweeps the ice into rubber containers the size of small swimming pools.

“This will be the most distant jacuzzi basin from the south in the world,” says Paul Anker, one of the engineers working for the British Polar Survey mission.

The rule that the team follows is very simple: they heat the water using boilers to a degree close to the boiling point, then sprinkle it on ice to melt it and dig into it.

Image caption

“The World’s Farthest Jacuzzi!”

But digging a 30-centimeter hole in about half a mile of ice in the front of one of the world’s most remote glaciers is not easy.

The temperature of the ice is about 25 degrees below zero, so the hole can freeze at any time, and the entire process is at the mercy of weather conditions and their fluctuations.

The rubber basin was filled with ice by early January, all equipment was ready, but we received a warning that another storm was about to blow.

Awafs in the Antarctic Antarctica can be very rough, and it is not uncommon for the continent to experience hurricanes and extremely low temperatures.

The gust storm was relatively weak for the Antarctic Antarctica, but nevertheless included winds of 50 mph for three days. Strong winds buried equipment and tents, and forced the team to stop work.

We had nothing to do but sit in the food tent, play gambling and have tea. As for the scientists, they were discussing the causes of the glacier’s decay quickly.

And they say what is going on here is a reflection of the complex interactions between climate, weather and ocean currents.

The most important factor in these reactions is in the warm sea water that runs from the other side of the globe.

As the Gulf Stream warm waters increase gulf stream) Cold between Iceland and Iceland, its waters are bathed.

The water is salty, which makes it relatively heavy, but its temperature is still one or two degrees above the freezing point.

A deep oceanic stream called the “Atlantic Carrier” transports this heavy saltwater to the southern Atlantic Ocean.

Image caption

Ice drilling process

Windy winds

Upon reaching the South Atlantic, it turns into a part of the current surrounding the Antarctic, running at a depth of up to a third of a mile under much colder waters.

It is known that the surface waters surrounding the Antarctic Antarctic continent are very cold, with almost two degrees below zero which is the degree of freezing of salt water.

The deep warm currents revolve around the Antarctic Antarctica, but recently began to approach the icy edge of the western part of the continent.

Here, the equation enters the phenomenon of climate change, as scientists say that the Pacific Ocean is hot, which leads to changing wind paths off the coast of western Antarctica, allowing deep warm water to flow over the continental shelf.

David Holland, an oceanographer at New York University and a senior worker at the “Grounding Zone” camp, says, “The temperature of the deep waters surrounding the pole does not exceed the temperature of the water above it by only one or two degrees above zero, but this difference is enough to set fire to This frozen river. “

Image caption

They dig in the ice

I was due to leave Antarctica by the end of last December, but due to obstructions and delays, the start date for the drilling process was postponed to January 7th.

On the same day, a satellite phone call came from the headquarters of the US Antarctic Antarctic Research Program at McMurdo Station.

We were told that we would not be able to postpone our departure time for any additional time, and that we had to leave on the cargo plane scheduled to arrive at our camp within an hour or about an hour.

It is very frustrating to be forced to leave before finishing the drilling of the ice hole and start using all the scientific equipment, especially if we take into account the difficulties that we incurred in order to get here.

We left our hosts and boarded the plane.

I looked back, and I saw the drilling rig running, and the hot water hose coming down the hole regularly.

The drilling process is almost halfway through.

The plane flew over the camp before heading north toward the ocean.

Scientists had told me that we were camping on a bay of ice surrounded by a horseshoe.

As we left the glacier, I was shocked to see the fragility of the place we were staying in.

Image caption

Tents in the ice

The size of the natural forces acting in this place as they tear and break the ice slowly cannot be ignored.

In some places, the great ice sheet has been completely shattered, and it has turned into pure ice floating in the sea.

Elsewhere, I’ve seen foothills of ice, some as high as a mile or a few miles above the sea floor.

The width of the glacier is about 160 km wide, and it collapses in seawater at a speed of 3 km per year.

This breakdown speed is really impressive, and it is the reason why the Thwits Glacier is a component of such great importance for sea level rise. But I was stunned to discover that another process might increase the speed of the glacier’s decay.

Increased frequency of dissolution

Most of the glaciers that flow into the seas are known to have an “ice pump”.

Sea water is known to be salt and dense, which makes it heavier. The water from melting ice is fresh water and less weight.

When the glacier melts, fresh water tends to climb upward, and warm, heavier seawater is pulled behind.

When the sea water is cold, this process takes place very slowly. The ice pump only melts at a rate of a few tens of centimeters per year, an amount that is easily compensated for by the new snow that is snowfall.

But the presence of warm water completely changes the face of this process, according to scientists.

Evidence from other glaciers indicates that the increase in the amount of warm water that reaches these rivers makes the ice pump run more quickly.

“She can set fire to glaciers, and she can increase the speed of melting these rivers 100 times,” says Holland.

The small plane took us to another camp in the middle of the western ice sheet, but the continuing storm prevented us from returning to McMurdo station for nine days.

Image caption

Hercules transport plane

A number of scholars joined us earlier.

It was a successful season by all accounts.

Scientists have been assured that the warm, deep waters surrounding the pole run under the glacier, and have been able to collect a tremendous amount of information.

The robot submarine was able to carry out five missions, during which it collected information from the waters under the glacier and took stunning pictures.

It will take several years to study this information and use it to accurately predict the future rate of seawater rise.

Sea level rise

The Thwits Glacier will not disappear overnight, as scientists say this process may take many decades or perhaps more than a century.

But that should not make us complacent.

A rise in seawater of one meter may not seem like much, especially if we consider that the tides in some areas may reach 3 or 4 meters every day.

But Professor David Vaughn, director of scientific affairs at the British Mission to Antarctica, says sea level levels have a major impact on flood intensity.

Let’s take a look at London, for example.

Any increase in seawater levels of 50 cm means that the severe storms that have been repeated every thousand years will occur every 100 years.

If the water levels rise by more than one meter, these storms will occur once every ten years.

“When you think about it, we shouldn’t be surprised at all of this,” says Vaughn as we prepare to board the plane that took us to New Zealand and then to Britain.

The increased carbon dioxide emissions pump more and more heat into the atmosphere and oceans.

Heat is energy, which is the energy that manages the climate and ocean currents.

He says if the amount of energy in the climate system increases, then the major global contexts must change.

These changes have already begun in the Arctic, and what we see now in the Antarctic Antarctica is nothing but another system that interacts with the changing factors in its own way.

Image caption

Icy slopes

Research and graphics: Alison Trozdel, Becky Del, Lily Hyun and Irene de la Touret

Photography: Gemma Cox and David Vaughn

Additional research: Professor Andrew Shephard from the University of Leeds



Source link
https://www.bbc.com/arabic/science-and-tech-51286303

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