Ice melting so faster: At first the images are cloudy.
The sediments pass quickly in front of the camera while Icefin , a bright yellow underwater robot operated by remote control, moves slowly under the ice.
Then the water begins to clear up.
Icefin is under almost 600 meters of ice, facing one of the fastest changing glaciers in the world.
Suddenly a shadow appears on him, a cliff of dirty ice.
It is a unique vision: the first image of a border that is changing our world.
Icefin arrived at the site where the warm waters of the ocean meet an ice wall at the front of the majestic Antarctic or Thwaites glacier , the point where this vast body of ice begins to melt.
“Judgment Day” Glacier
Glaciologists describe the Thwaites as the “most important” and “most dangerous” glacier in the world . They also tell him the “Judgment Day” glacier .
It is located in the Antarctic sector that is not claimed by any country, and flows into the Amundsen Sea , about 30 kilometers east of Mount Murphy , in the land of Marie Byrd .
It is giant, almost the size of the United Kingdom, and is already responsible for 4% of the global rise in sea level , a huge figure for a single glacier.
But satellite data shows that it is melting faster and faster .
The Thwaites contain enough water to increase the level of the world’s seas by more than half a meter.
And Thwaites is located as a cornerstone right in the center of the West Antarctic ice sheet, a vast mass of ice that contains more than three potential meters of additional sea level rise.
And so, until this year, no one has attempted a large-scale scientific research on the glacier.
The Icefin team, along with 40 other scientists, are part of the Thwaites Glacier International Collaboration , a joint effort by the United Kingdom and the United States for five years and $ 50 million to understand why it is changing so quickly.
It is the largest and most complex scientific field project in the history of Antarctica.
When I was invited to report on the team’s work, I was certainly surprised at how little is known about such an important glacier.
When I got there I discovered why.
Snow on the Antarctic program airfield ice rink delayed my flight from New Zealand to McMurdo , the main US research base in Antarctica.
This was the first of a complete catalog of delays and alterations.
It takes weeks for scientific teams to reach their research fields.
Why is Thwaites important?
Western Antarctica is the most stormy part of the most stormy continent in the world.
And the Thwaites glacier is remote even by Antarctic standards, more than 1,600 km from the nearest research base.
But understanding what is happening here is essential so that scientists can accurately predict future increases in sea level.
Ice in Antarctica contains 90% of the world’s fresh water , and 80% of that ice is in the eastern part of the continent.
The ice in eastern Antarctica is very thick, with an average thickness of 1.6 km, but it rests on high ground and only looks a little towards the sea.
Western Antarctica, however, is very different. It is smaller – although still huge – and is much more vulnerable to change.
Unlike the east, the western part does not rest on high ground. In fact, virtually all of its base is well below sea level.
If it weren’t for ice, it would be a deep ocean with a few islands.
I had been in Antarctica for five weeks when I was finally able to board the twin-engine aircraft of the British Antarctic Survey (BAS) that would take me to the glacier.
I camped with the team in what is known as the base zone.
The camps are on the ice located at the point where the glacier meets the ocean water and the team has the most ambitious task of all.
They need to drill almost 800 meters of ice right at the point where the glacier is afloat.
They will use the hole to access the sea water that is melting the glacier to discover where it comes from and why it is attacking it so vigorously.
He doesn’t have much time.
There are only a few weeks left in the Antarctic summer before the weather really gets worse.
Dr. Kiya Riverman , a glaciologist at the University of Oregon (USA), drills with an ice drill and places small explosive charges.
The rest of us make holes in the ice for the geophones, the electronic ears that will hear the echo of the explosions that bounce from the foundations through layers of water and ice.
Thwaites rests on the seabed
The reason why scientists are so worried about the Thwaites is the downward tilt of the underwater bed .
This means that the glacier becomes increasingly thick as you travel inland.
At its deepest point the base of the glacier is more than 1.6 km below sea level and there is another 1.6 km of ice on it.
What seems to be happening is that the hot water of the deep ocean is flowing towards the coast and under the ice facade, melting the glacier.
As the glacier recedes, more ice is exposed.
It’s a bit like cutting slices of the edge of a piece of cheese.
The surface area of each one becomes larger and larger, providing more and more ice for the water to melt.
And that is not the only effect.
Gravity makes ice flat. As the glacier’s facade melts, the weight of the vast reservoir of ice behind it moves forward.
What he wants is to “crush,” Riverman explains. The higher the ice cliff, the greater the “crushing” that the glacier wants to make.
Thus, the more the glacier melts, the more likely the ice in it will flow faster.
“The fear is that these processes will accelerate,” he says. “It’s a vicious circle, a circle that feeds back.”
Being able to carry out research at this scale in such an extreme environment does not only require transporting a few scientists to a remote location.
Tons of specialized equipment and tens of thousands of liters of fuel are needed, in addition to tents and other supplies and food.
I camped on the ice for a month, some of the scientists will be there much longer, two months or more.
It took more than a dozen flights from the Hercules cargo aircraft fleet of the US program to take scientists to the main project site, in the middle of the West Antarctic ice sheet .
Later smaller airplanes transported people and supplies to the camps, hundreds of kilometers from the glacier.
The distances in this place are so great that another camp needs to be established halfway between the glacier so that the planes can refuel.
The contribution of the BAS was an epic journey on land that transported hundreds of tons of fuel and cargo.
Two icebreaker ships docked at the shore of the Antarctic Peninsula last summer.
With a team of drivers of special vehicles for snow they moved more than 1,600 km through the ice sheet on one of the most inhospitable terrain and weather on Earth.
Ice drilling – Ice melting so faster
The scientists at the base zone camp plan to use hot water to drill the hole in the ice.
They need 10,000 liters of water, which means that you have to melt 10 tons of snow.
“It will be the southernmost jacuzzi in the world,” jokes Paul Anker , the BAS drilling engineer.
The principle is simple: you heat the water with boilers just below the boiling point and then spray it on the ice, melting it.
Drilling a 30 cm hole along 800 meters of ice in one of the most remote glaciers in the world is not easy.
The ice is at -25 ° C so the hole is likely to freeze fast and the whole process will depend on the weather.
The storms of Antarctica can be very intense. It is not unusual to have hurricane winds in addition to extremely low temperatures.
The one that touched us was relatively moderate for Antarctica but we still spent three days with winds with speeds of up to 75 km per hour.
That meant stopping work.
Scientists say the glacier is melting so fast due to a complex interaction of weather, temperatures and ocean currents.
The key is hot seawater , which originates from the other side of the world.
As the Gulf Stream cools between Greenland and Iceland, the water dissipates. This water is salty, which makes it relatively heavy, but has a degree or two above the freezing point.
This heavy salt water is transported by a deep ocean current, called the thermohaline circulation of the Atlantic , to the south.
This is then part of the Antarctic circumpolar current that flows under a much colder layer of water.
The surface water in Antarctica is very cold, just above -2 ° C, the freezing point of salt water.
Circumpolar water travels around the continent but with increasing frequency it has been accumulating on the western Antarctic border.
And this is where our climate change comes into action.
Scientists say the Pacific Ocean is warming and wind patterns are changing on the coast of western Antarctica, allowing hot, deep water to accumulate on the continental shelf.
“Antarctic circumpolar deep water is only a few degrees hotter than the water above it, a degree or two above 0 ° C, but that is hot enough to turn on this glacier,” says David Holland , oceanographer at the University of New York and one of the leading scientists in the base camp.
I was leaving Antarctica at the end of December but a call came from the US program telling us that we could not delay flights and we should leave the camp in an hour or two.
And with the delays the drilling could begin until January 7.
It was very frustrating to have to leave before the hole was finished, considering all the time it took us to get there.
We say goodbye and board the plane.Ice melting so faster.
The plane flies over the camp and into the ocean in the north.
As we fly over the facade of the glacier I realize how fragile it is.
No doubt there are epic forces working here, slowly shattering and devastating the ice.
In some places, the great ice sheet has broken completely, collapsing in a jumble of massive icebergs that float chaotically.
Elsewhere there are ice cliffs, some of which rise almost a kilometer from the seabed.
The facade of the glacier is almost 160 km and is collapsing towards the sea at a rate of 3 km per year.
The scale is impressive and explains why Thwaites is already such an important component of the global increase in sea level, but I am amazed to discover that there is another process that can accelerate its retreat even further.
Melt rates increase – Ice melting so faster
Most glaciers that flow into the sea have what is known as an “ice bomb.”
Marine water is salty and dense which makes it heavy. Melted water is sweet and therefore relatively light.
As the glacier melts, fresh water tends to flow upward, attracting warmer salt water.
When the sea water is cold this process is very slow, the ice pump often melts only a dozen centimeters a year, balanced by the new ice that is created with the falling snow.
But hot water transforms the process, scientists say.
Evidence from other glaciers shows that if you increase the amount of hot water that is reaching the glacier, the ice pump works faster.
“It can ignite glaciers,” increasing melt rates up to a hundred times, “says Professor Holland.
For scientists it has been a successful season.
They confirmed that the deep circumpolar hot water is entering under the glacier and collected a huge amount of data.
Icefin, the underwater robot, managed to perform five missions, taking several measurements in the water under the glacier and recording extraordinary images.Ice melting so faster.
It will take years to process all the information that the team has gathered and incorporate the findings into the models that are used to project the future rise in sea level.
The Thwaites will not disappear overnight, but scientists say it will take decades, possibly more than a century.
But we must not be complacent.
A meter of rise in sea level may not sound much, but this has a huge effect on the severity of the storms, says Professor David Vaughan , director of the BAS .
An increase in sea level of 50 cm would mean that the storm that used to occur every thousand years will now occur every 100 years.
If the increase is one meter, the millennium storm will occur every decade.
“This should not surprise us,” says Professor Vaughan.
The increasing levels of carbon dioxide are exerting much more heat in the atmosphere and the oceans.
Heat is energy and energy drives climate and ocean currents.
If you increase the amount of energy in the system, he says, inevitably the big global processes will change.
“They already have that in the Arctic,” says Professor Vaughan. “What we are seeing here in Antarctica is just another huge system responding in its own way.”
Sources La nacion
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