When Scientists Scanned Below The Antarctic Ice, They Found A Secret That Could Change Our Future
Scientists may have discovered the world's largest canyon, buried under a vast Antarctic ice sheet. Antarctica's ice sheet is the largest single mass of ice found anywhere on Earth, but it is full of mysteries.
Half of the Antarctic ice sheet is more than three miles from any bed topography measurement, and major data gaps exist in several parts of this frigid continent. There is now a detailed map of Antarctica's peaks and valleys, with more being discovered every day.
James Cook Was The First To Navigate The Frozen Land
James Cook was the first to navigate the Antarctic, and ever since then, mankind has seemingly been fascinated by the mysteries of Antarctica. Cook was an explorer for the British Royal Navy, and he explored the area.
However, he never actually found the continent, although he was only eighty miles from the coast. More modern technology has helped scientists discover more about Antarctica, but there is still so much left to uncover.
A New Map Of Antarctica
A new map of Antarctica was created by a team of researchers that used physics and modern technology. As a result, it is now officially the most well-mapped-out region in the world.
"It's a bit like being almost blind and putting on glasses for the first time and seeing 20/20." ---- Researcher. As a result of the study, the scientists have some worrying insights into the possible problems from climate change. The results from the study were released in 2019.
Global Temperatures
Antarctica has experienced an air temperature increase of three degrees, which is five times the mean rate of global warming. Because of the temperature change, many glaciers have retreated, with some of the ice shelves collapsing completely.
Scientists are worried about what will happen if the ice sheet melts, so they are gathering all of the information that they can so they can accurately predict the future. Global temperatures continue to rise, therefore, increasing the concern.
Antarctica Is The Least Visited Continent
Antarctica is the world's least-visited and least populated continent. One of the main reasons is that it is hard to get to, but that doesn't stop people from wanting to go there. It is the appeal of the unknown, and roughly ninety percent of tourists to Antarctica come by boat.
About five and a half million square miles are not home to any residents, and only a few tourists and researchers visit every year. Most travelers spend only a few hours on the land before leaving.
Harsh Frozen Tundra
Antarctica is almost entirely covered in ice, and in most places, the ice goes down more than six thousand two hundred feet. The area is harsh and difficult for humans to live in, but there are a few select animals that have made it their homes, such as seals and penguins.
Everything about Antarctica is extreme, with the average temperature around minus seventy degrees Fahrenheit. The coastal winds can reach up to two hundred miles an hour, leading to violent blizzards that usually last a week at a time.
Antarctica Had No Indigenous Population
Antarctica had no indigenous population, and humans didn't even know about the frozen tundra until the 1770s. Scientists and researchers have attempted to uncover some of its secrets, but it is no easy task. Antarctica is isolated from other areas by the distance, climate, and storminess of its seas.
Other than seals and penguins, nothing else can survive full-time on the land. In 1820, the technology and navigation were finally sophisticated enough for humans to sail far enough south to Antarctica.
Under Antarctica
There have been previous airborne surveys over Antarctica that relied mainly on radar and were not able to measure the trough's full depth. "There have been many attempts to sound the bed of Denman, but every time they flew over the canyon, they couldn't see it in the radar data." ----- Mathieu Morlighem.
The researchers used pulses of microwave radiation to see beneath the frozen tundra and build up a picture of what lies beneath. However, it always had its limitations, until now, because the technology has greatly approved.
Limitations
The deepest parts of Antarctica are too deep for radar technology to be able to map the terrain accurately. It's tricky because the microwaves bounce off the walls and trenches and never actually reach the bottom.
"The trough is so entrenched that you get side-echoes from the walls of the valley, and they make it impossible to detect the reflection from the actual bed of the glacier. In fact, the bed of Antarctica is less well-known than the surface of Mars." ----- Dr. Stewart Jamieson.
2019 Study
Understanding how ice flows in Antarctica has become increasingly crucial as the Earth warms. In 2019, a team of researchers from Australia, India, Europe, South Korea, China, and the United States began studying what lies beneath the Antarctic ice.
The study was led by the University of California, and the results were later published. The results were fascinating and also scary, as they showed that there is definitely cause for concern.
BedMachine Antarctica
The BedMachine is a new Antarctic bed topography product that is based on ice thickness data from different research institutes dating back to 1967. It involves nearly a million line miles of radar soundings, and it relies on the fundamental physics-based method of mass conservation.
In addition, it utilizes highly detailed information on the ice flow motion from satellite data that dictates how ice moves. BedMachine Antarctica was a program that was started in order to build the most accurate map to date of the terrain beneath the sheet of ice.
Different Approach
The researchers used the data they had received so far as a starting point in constructing a map of Antarctica. However, they still had a large area of Antarctica that was uncharted. The scientists and researchers decided to use a different approach and used the method known as mass conservation.
They combined satellite measurements that tell us where the ice goes, with the rate of known accumulation and melting at the surface. They calculated the available ice thickness measurements from radars using the principle of mass conservation.
The Principal Of Mass
The mass balance of a glacier is critical to all theories of glacier flow and behavior. It is simply the gain and loss of ice from the glacier system, and a glacier is a product of how much mass it receives and how much it loses by melting.
Mass balance is the 'health of a glacier,' and as glaciers lose more mass than they receive, it will be in negative mass balance. Therefore, the glacier will recede, and if it receives more than it loses, it will advance.
Researchers Find The Answer
Scientists have made numerous scientific discoveries of global significance in Antarctica that have given them much insight. In fact, BedMachine's researchers now have a much better picture of the Antarctic terrain and of what lies beneath the ice.
This is because they followed the principle of mass conservation, and by doing that, they successfully established how much ice is trapped under the continent and what else is down there. It has also helped them understand the effects of global warming.
Filling In The Holes
The researchers used satellite data to determine exactly how the ice was moving across Antarctica. They learned how much frozen matter was entering the continent's valleys and just how quickly it was moving.
The scientists were filling in some of the holes of their knowledge that radar just couldn't penetrate. They are continuing to gather all of the data and information that they can to learn what is happening in the freezing tundra and what can be done about it.
Invaluable Knowledge
Modern technologies such as surface, aerial, and underwater drones have helped and will continue to give scientists invaluable knowledge. The scientists will be able to learn even more now that they have established the volume of ice in Antarctica's valleys.
They determined how deep the features stretched beneath the surface, and they were even able to predict the exact shape and contours of the valley floor. As a result, they are revealing more and more of Antarctica's mysteries.
Detailed Map Of Antarctica
Finally, the research results were made public and released on December 12, 2019. First, it was released in the scientific journal Nature Geoscience; the results showed that the researchers had succeeded in creating the most detailed map of Antarctica.
"If this paper is right, it changes the ball game for sea-level rise in this century." ------ Michael Oppenheimer. The newest map is the most detailed out of all continents.
Record-Breaking Canyon Found
The study and research in 2019 revealed a record-breaking canyon hidden beneath the surface of Antarctica. The canyon is under four kilometers of ice and is the deepest land on Earth. It is located under the Denman Glacier, and the discovery will help forecast future ice loss.
The canyon reaches eleven thousand feet down the sea level, deeper than the Dead Sea, and covered by a thick layer of ice. The images taken have been able to show the mountains and valleys.
Denman Glacier
Denman Glacier sits above the deepest canyon that was discovered in Antarctica. It is seven to ten feet wide and was named for Lord Denman, Governor-General of Australia.
In 2020, it was found that Denman Glacier has retreated significantly and is one of the few ice streams that have been identified as requiring special attention. The findings that Denman is unstable have contributed to a shift in the perception of change in East Antarctica.
The Deepest Point
The exciting thing about the Denman Glacier is that the canyon lies beneath it, underneath all of the ice. Because of the BedMachine project, researchers learned that the valley reaches eleven thousand and five hundred feet below.
In addition, it is the deepest point ever to be discovered on the surface of the Earth. It is an ice-filled canyon under Denman Glacier, and only in the ocean are the valleys deeper. There are land canyons that have taller sides, but their floors are above sea level.
Eight Times Deeper
Before researchers discovered the deep canyon below Denman Glacier, the deepest known point on land was located thousands of miles away on the edge of the Dead Sea. However, it is only one thousand, three hundred and fifty-five feet below sea level.
The new canyon measures about eight times deeper than the canyon in the Dead Sea. Other deep canyons are the Grand Canyon, which is merely eighteen hundred meters deep, and Yarlung Tsangpo Grand Canyon in China.
Deepest Point On Dry Land
Earth's deepest point of the continents has been identified in Queen Mary Land, East Antarctica, the canyon buried under the ice of the Denman Glacier. The glacier is far from the deepest point on Earth as a whole, but on dry land, it is definitely a record holder.
The lowest exposed land on Earth is the Jordan Rift Valley in the Dead Sea. However, the Mariana Trench in the Pacific Ocean is the deepest point on Earth, but it is geologically speaking part of the oceanic crust.
Not A Comparison
Many have compared the canyon beneath Denman Glacier to China's Yarlung Tsangpo Grand Canyon. The Yarlung Tsangpo reaches a depth of almost twenty thousand feet, which makes it a record-breaker.
However, its floor is not below sea level, as where the canyon beneath Denman Glacier is far below sea level. There are canyons that are capable of giving Antarctica's a run for its money, but often the comparison seems unjust.
Massive Achievement
In years past, the radar data just couldn't reach deep enough. However, since having new technology, much has been achieved. "There have been many attempts to sound the bed of Denman, but every time they flew over the canyon, they couldn't see it in the radar data." ------ Researcher.
With new technology, the researchers were able to find that Denman's western flank has retreated almost three miles and that a deep canyon below the glacier may be the cause of the glacier melting faster than it can recover.
Entrenched Trough
The glacier's trough is so entrenched that with the radar, you get side echoes from the valley walls, which makes it impossible to detect the reflection from the actual bed of the glacier. The researchers have now been able to measure the trough's full depth with the BedMachine project.
BedMachine works differently because it combines information about ice flows and seismic activity along with radar to create the most detailed and complete picture of Antarctica's landscape yet.
Earned Its Place In The History Books
The BedMachine project has, without question, earned its place in the history books. The discovery alone is an achievement that may help to pave the way for a deeper understanding of how climate change has and will affect our planet.
Morlighem and his colleagues found the deepest point on the surface of the Earth. The team's results are published today in AGU's journal, Geophysical Research Letters.
Glacial Retreat
Several glaciers have begun to retreat as the Earth's temperatures have increased. Landscapes that slope inland can actually speed up the process and cause rising sea levels. However, certain geographical features can have the opposite effect.
For example, Denman's eastern flank is protected from a retreat by a subglacial ridge. Sadly, its western flank is characterized by a deep and steep trough with a bed slope conclusive to accelerated retreat.
Transantarctic Mountains
The Transantarctic Mountains are a mountain range of uplifted rock that extends across the continent from Cape Adare in Northern Victoria Land to Coats Land.
They divide East and West Antarctica. Several glaciers have formed on the eastern coast of the frozen continent and flow into the Ross Sea. A floating sheet of ice stems their movement, and some researchers have held concern about what might happen if that sheet melts.
Challenging A Preconception
The previous models and maps have had researchers predicting that the ice sheet melting would speed up the rate at which the glaciers feed into the Ross Sea. However, the BedMachine project has revealed the truth, data that could challenge the preconception.
The study discovered that a high ridge runs beneath the ice. BedMachine utilizes highly detailed information on ice flow motion from satellite data that dictates how ice moves.
False Alarm
The researchers have learned that the ridge could slow down the rate at which the Transantarctic Mountain's glaciers drain into the sea. Learning this had made them believe that the melting of the Ross Sea ice shelf might not be quite as catastrophic as they had once feared.
According to Morlighem's notes, the hypothetical scenario of a faster retreat could just be a false alarm. "Using BedMachine to zoom into particular sectors of Antarctica, you find essential details such as bumps and hollows beneath the ice that may accelerate, slow down, or even temporarily stop the retreat of glaciers." ------ Mathieu Morlighem.
East Antarctica Could Be Threatened
It has been thought that East Antarctica is threatened, but they have been able to study Denman closer. They are beginning to see evidence of potential marine ice sheet instability in this region.
The configuration of the steep trough could funnel warm seawater underneath the ice and make for an unstable ice sheet. In addition, the warm water is increasingly being pushed against the Antarctic continent by winds, which are called the westerlies.
Glacier Flowing Into The Amundsen Sea
On the other side of Antarctica, there is a vast glacier that is about the size of the United Kingdom, and it flows into the Amundsen Sea. It is one of the area's fastest-moving ice shelves and travels more than a mile each year.
However, the BedMachine project's data shows that the icy mass could retreat even faster in the future. The model results highlight the importance of damage for ice shelf stability, grounding line retreat, and future sea-level contributions from Antarctica.
Thwaites Glacier
Thwaites Glacier sits on top of a landscape that slopes inland, and its type of terrain typically speeds up the retreat. Thwaites Glacier is sometimes referred to as the Doomsday Glacier and is among the fastest-changing outlet glaciers in Antarctica.
Projecting the future of the Thwaites Glacier and other glaciers remains a major uncertainty for sea-level rise. The glacier has thinned, and its grounding lines have retreated. The ice shelf thinning decreases the effect they exert on the upstream glaciers.
A Cause For Concern
According to the study, there are two ridges in the land surrounding Thwaites Glacier, and they are eighteen to thirty miles away from its current location. Once the retreating ice has passed the point of the two ridges, there could be no chance of stopping it.
Experts have stated that because of the large size of the glacier, this could be a cause for concern. If Thwaites Glacier were to collapse, it would open the door for the rest of the West Antarctic ice sheet to slide into the sea.
Dr. Emma Smith
Dr. Emma Smith worked with Morlighem on conducting research in Antarctica. Dr. Smith's focus was on analyzing 3-D seismic data across the eastern shear margin of Thwaites Glacier.
This was to understand better what is allowing the margin between fast and slow-flowing ice to exist in the area and how it might change with changing environmental conditions. According to Dr. Smith, the process is similar to how a thick liquid moves across a surface.
Just Like Treacle
Dr. Emma Smith explained how the ice in Antarctica behaves. She explained, "Imagine if you poured a bunch of treacle onto a flat surface and watched how it flowed outward.
Then pour the same treacle onto a surface with a lot of lumps and bumps, different slopes and ridges, the way the treacle would spread out would be very different." Thwaites Glacier looks more like a jumble of icebergs that have been joined together, and it is jagged and scarred.
Other Glaciers
The Thwaites Glacier and the Transantarctic Mountains are not the only regions to be exposed by the BedMachine project. The researchers also learned a lot more about the terrain beneath the Recovery Glacier in northwest Antarctica.
The Recovery Glacier is about sixty miles long, and the ice sheet currently sheds about thirty-five billion tons of ice and water every year. There are five large and well-known glaciers in Antarctica, but there are hundreds of other smaller glaciers in the region.
Understanding Better
The team of researchers and scientists will use the information gathered from their study and from BedMachine to update the models and maps of how Antarctica might respond to climate change.
Their hope is that with the updated and more accurate data, they can build a better understanding of how the continent will change as the temperature rises. They will also be able to see if there is anything that can be done about it.
Finding Solutions
This work and research are vital so that we can survive the effects of climate change. Experts have said that in the last eighteen years, as much as three trillion tons of ice has vanished from Antarctica.
If the climate continues to get warmer, more ice will vanish, which will result in the sea levels rising across the world. There is most likely nothing that can be done about this problem, but at least they can understand it better and try to come up with solutions.
Colony-Forming Invertebrates
While the researchers were discovering the canyon miles under the ice, they also discovered sea creatures that included colony-forming invertebrates called bryozoans and serpulid worms. It is thought that the organisms are eating algae carried beneath the ice shelf by currents. They also discovered fragments of dead animals that were up to five thousand eight hundred years old.
"This discovery of so much life living in these extreme conditions is a complete surprise and reminds us how Antarctic marine life is so unique and special. It's amazing that we found evidence of so many animal types; most feed on micro-algae, yet no plants or algae can live in this environment." ------ David Barnes.
The Ross Ice Shelf
The largest ice shelf of Antarctica is the Ross Ice Shelf, as it is more than three hundred and seventy miles long and fifty to one hundred and sixty feet high above the water surface. It is nearly a vertical ice front to the open sea and several hundred meters thick.
About ninety percent of the floating ice is below the water surface. The Ross Ice Shelf has been considered stable, but it is also at risk now and could cause problems because if it melts, it won't be able to slow the flow of glaciers.
Filchner-Ronne Ice Shelf
The Filchner-Ronne Ice Shelf borders the Weddell Sea, and it covers about 430,000 km2. The ice shelf is the second-largest ice shelf in Antarctica, and it grows perpetually due to a flow of inland ice sheets.
If the ocean cavity beneath the large glacier were to become flooded with warm water from the deep ocean, a potentially irreversible threshold in Antarctic ice shelf melting would be crossed. Climate change weakens the circulation beneath the ice shelf, which leads to colder water and reduced melting.
Amery Ice Shelf
The Amery Ice Shelf is located at the head of Prydz Bay between the Lars Christenson Coast and Ingrid Christensen Coast. The ice shelf was named for William Bankes Amery.
Scientists are concerned about the Amery Ice Shelf because there have been enormous cracks forming for over a decade at a rate of three to five meters a day. There has been melting and freezing under the ice shelf, and ice shelves are sensitive to changes in air and ocean temperatures or circulation near Antarctica.
Alfred Wegener Institute
The Alfred Wegener Institute has a station called Neumayer Station III on the Ekstrom Ice Shelf in Antarctica. It is where researchers can live and work year-round as the station is built on a platform above the snow-covered surface.
The station's external hull hides a total of one hundred containers, which consist of living and sleeping quarters, kitchen, hospital, radio room, mess hall, and sanitary facilities. Up to fifty people live and work at the station during the summer, and in the winter, only a few people remain. The researchers work in the facility, where there are observatories for geophysics, hydroacoustic, and meteorological research stations.
Subglacial Lake
There have been three hundred and seventy-nine subglacial lakes identified beneath the Antarctic continent. The lakes are interconnected, and water flows from one lake to another.
Some of the lakes have been isolated from the outside world for up to thirty-five million years. They can cause changes in ice flow by draining quickly and lubricating the ice-bed interface, which allows ice streams to flow even more rapidly.
Princess Elizabeth Antarctica
Princess Elizabeth Antarctica is a section of Antarctica that is the first-ever 'zero emission' station. The station has scientists from around the world that are conducting research on Antarctica's environment.
They integrate passive building technologies, renewable wind and solar energy, and water treatment facilities. The largest research station in Antarctica is McMurdo Station, and all of these research stations have a mission to learn more about Antarctica.
The Denman Trough
Denman Glacier flows over, the recently discovered, deepest land canyon on Earth, and the glacier's edge continues to retreat farther down the slope. It will eventually turn the Denman trough into a giant bowl of meltwater with nowhere else to go.
"Because of the shape of the ground beneath Denman's western side, there is potential for rapid and irreversible retreat, and that means substantial increases in global sea levels in the future." ------ Virginia Brancato.
Grounding Line Is Key
The Grounding Line is the point where glaciers and ice shelves start to float. It is extremely important where the line is located because the mass loss from Antarctica is strongly linked to changes in the ice shelves and their grounding lines.
Changes in the line can result in drastic and rapid changes in glacier and ice shelf behavior. They are more of a zone, which is the region where ice transitions from a grounded ice sheet to a freely floating ice shelf.
Pine Island
Pine Island is a glacier, large ice stream, and is the fastest melting glacier in Antarctica. It is responsible for roughly twenty-five percent of Antarctica's ice loss, and the area drained by Pine Island Glacier comprises about ten percent of the West Antarctic Ice Sheet.
An iceberg that was twice the size of Washington, D.C., broke off from the glacier in 2020, and the glacier's ice velocity has accelerated to over thirty-three feet per day.
Predictions For The Future
Researchers have been able to learn a vast amount about the terrain beneath the glaciers in Antarctica, which is all thanks to BedMachine. The bed is crisscrossed by trenches that are hundreds of feet deeper than previously believed.
Because the researchers now have a much clearer picture of what lies beneath Antarctica, and with all of the knowledge they now have, they are more able to improve the predictions for the future.