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December 21, 2021

 


There is nothing but darkness deep beneath the ice of Antarctica's Ekström Ice Shelf.

According to a new article by academics from the UK and Germany, full darkness and a functioning ecosystem have persisted for thousands of years.

"This discovery of so much life flourishing in such harsh conditions is a complete surprise and serves as a reminder of how rare and precious Antarctic marine life is," says lead author and British Antarctic Survey marine biologist David Barnes.

"It's incredible that we found evidence of so many different animal species, the majority of which feed on microalgae (phytoplankton), despite the fact that no plants or algae can survive in this environment. So, how do these animals survive and thrive in this environment?"

Back in 2018, the researchers used hot water to drill two boreholes on the comparatively modest Ekström Ice Shelf in East Antarctica. The first hole stretched down 192 metres (630 feet) of ice until it reached 58 metres of liquid water, while the second hole covered 190 metres of ice with 110 metres of water beneath it.



They discovered life in that dark, cold, and food-scarce environment beneath the ice, and plenty of it. The researchers discovered 77 species of bryozoans from 49 distinct genera, including Melicerita obliqua, a sabre-shaped worm, and Paralaeospira sicula, a serpulid worm.

All of these animals are suspension feeders, meaning they sit in one spot and pluck organic materials from the water as it flows around them with their feathery tentacles, implying that some form of food supply, such as sunlight-dependent algae, must be getting in under the ice sheet.

Given that the nearest open water source is 9.6 kilometres (6 miles) distant, this is somewhat remarkable. On larger ice sheets like the Ross and McMurdo Ice Shelves, earlier study has discovered life much further inland.

"Life has been observed even 700 km from ice shelf borders despite perpetual darkness for at least thousands of years," the researchers wrote in their report.

"The diversity and quantity of life beneath ice shelves was assumed to be in short supply. Even for open-marine Antarctic continental shelf samples, the biodiversity we discovered at both borehole sites would be considerable."

Fragments of four Cellarinella species even revealed development increments, comparable to tree rings, which the researchers noticed were similar to other sized growth increments seen in samples from around Antarctica.



The researchers didn't simply seek for today's filter feeders deep beneath the ice; they also looked for long-dead bits and carbon-dated them to figure out how old they were.

"Another surprise was learning how long people had lived here. The carbon dating of these bottom animals' dead fragments ranged from current to 5,800 years "Gerhard Kuhn, a geologist at the Alfred Wegener Institute for Polar and Marine Research, is one of the researchers.

"Despite living 3-9 kilometres from the nearest open water, an oasis of life may have flourished under the ice sheet for approximately 6,000 years. Only samples taken from the seabed beneath the floating ice shelf will reveal information about the ice shelf's past."

This raises another issue: how did these dark ecosystems survive past glacial cycles when most of the Antarctic shelf was covered in grounded ice (ice that reaches all the way to the sea floor)?

According to the new findings, the organisms resided in small, un-grounded areas, whereas open areas of water surrounded by sea ice would have allowed phytoplankton to bloom and then be consumed by critters living far beneath the ice. The plankton would have been pushed beneath the ice by the water's flow, where it would have been within reach of the hungry critters below.

Unfortunately, despite these ecosystems' unusually long lives thus far, the researchers are concerned about their future.

"In most areas, it may be cold, dark, and food-scarce," the team writes, "yet the least disturbed habitat on Earth could be the first habitat to become extinct if sub-ice shelf conditions disappear owing to global warming."


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October 14, 2019

Ninety-nine per cent of all freshwater ice on Earth is sitting on top of Greenland and Antarctica, and
each year, a little more of it melts into the ocean.
Normally, it would take hundreds to thousands of years for it all to melt away. But what if something
happened that caused a massive global melt overnight?
As we slept, sea levels would rise by a whopping 66 meters. Coastal cities like New York, Shanghai,
and London would drown in the apocalyptic mass flood, forcing up to 40 percent of the world's population
out of their homes.
While all this chaos ensues above-ground, something equally sinister is happening below. All that rising
saltwater will infiltrate
groundwater reserves farther inland, forcing its way into nearby freshwater aquifers.
You know, the ones that supply our drinking water, irrigation systems, and power-plant cooling systems?
All those aquifers would be destroyed. Not good.
On top of that, the ice on Greenland and Antarctica is made of freshwater, so when it melts, that's about
69 percent of the world's freshwater supply that's going straight into the oceans. This will wreak
havoc on our ocean currents and weather patterns.
Take the Gulf Stream, for example. It's a strong ocean current that brings warm air to northern Europe
and relies on dense, salty water from the Arctic in order to function. But a flood of freshwater would
dilute the current and could weaken or even stop it altogether.
Without that warm air, temperatures in northern Europe would plummet, and that could spawn a
mini ice age, according to some experts.
That's not even the worst of it. Take a look at what will happen when that last 1 percent of freshwater
ice that's not part of Greenland or Antarctica thaws. Some of that 1 percent is sitting in glaciers farther
inland.
The Himalayan glaciers specifically pose one of the largest threats because of what's trapped inside:
toxic chemicals like dichlorodiphenyltrichloroethane, or DDT. Scientists discovered that glaciers
like this can store these chemicals for decades. But as they thaw, those glaciers release the chemicals
into rivers, lakes, and groundwater reserves, poisoning each one as they go.
The rest of that 1 percent is hanging out underground, mostly in the Arctic tundra, as something
called permafrost. Permafrost is organic matter that's been frozen in the ground for two-plus years.
Now, one of the most immediate problems with thawing permafrost would be mercury poisoning.
That's right: There are an estimated 15 million gallons of mercury stored up in the Arctic permafrost.
That's almost equal to the amount of mercury everywhere else on Earth.
On top of that, the organic matter in permafrost is a tasty meal for microorganisms. After they digest it
all, they fart out two of the most potent greenhouse gases out there, carbon dioxide and methane.
Scientists estimate this could double the current levels of greenhouse gases in the atmosphere, and
potentially cause global temperatures to rise by 3.5 degrees Celsius compared to today.
That might not sound like much, but say goodbye to that mini European ice age, and even rivers
and lakes around the world. They'd evaporate from the higher temperatures and cause mass droughts
and desert-like climates. And all that extra water vapour in the atmosphere would fuel more frequent
and stronger storms, floods, and hurricanes.
So all of that newly established coastline on the eastern US would be one of the last places you'd want
to live. Instead, there would be mass migrations to Canada, Alaska, the Arctic, and even what's left
of the Antarctic.
And you're right, this is probably never going to happen. After all, there's enough ice right now to cover
the entire continent of North America in a sheet a mile thick.
So the next time you hear about record-breaking heat or ultra-powerful hurricanes, at least you know
that it could be worse. But scientists estimate that if we don't take action and global temperatures
increase by just 1 degree Celsius, the effects of climate change we already see today will be irreversible.
So yes, it could be worse, and it will be if we're not careful.
This is a transcript of the embedded video.

This article was originally published by Business Insider.
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August 24, 2016
massive_crack_threatening_to_cause_an_entire_Antarctic_ continent
An iceberg the size of Delaware is about to break free.
Scientists have been monitoring a fracture in one of the world’s biggest ice shelves, and report that in the last five months alone, it’s grown an extra 22 kilometres (13.67 miles) in length, and now stretches for a total of 130 km (80 miles).
It’s now only a matter of time before a massive chunk of this Antarctic ice shelf - known as Larsen C - breaks free, and then we’ll have the third largest loss of Antarctic ice in recorded history on our hands.
Located on the coast of the Antarctic Peninsula, the Larsen ice shelf is split up into three smaller ice shelves - Larsen A, B, and C. Larsen A and B have already experienced massive declines over the past two decades, and now Larsen C, the biggest of them all, is in a world of trouble itself.
Researchers from Project MIDAS, a British Antarctic Survey that involves teams from several UK universities, report that around 12 percent of the entire Larsen C ice shelf is expected to break off, leaving the exposed ice front at its most retreated position ever.
"Computer modelling suggests that the remaining ice could become unstable, and that Larsen C may follow the example of its neighbour Larsen B, which disintegrated in 2002 following a similar rift-induced calving event," they report in a blog post.
What’s left of the Larsen B ice shelf is widely considered to be on borrowed time, having lost a chunk of ice the size of Rhode Island back in 2002. Remember this?
It now covers an area of 1,600 square kilometres (625 square miles), and is expected to disintegrate by the end of the decade. That’s pretty devastating, when you consider that Larsen B has been stable for at least the past 12,000 years.
The Larsen A ice shelf disintegrated in January 1995, and now Larsen C looks like it’s on its way out too.
Just to give you an idea of how much ice we’re talking about here, Larsen C covers around 55,000 square km (21,235 square miles). That’s 10 times the size of Larsen B, and about half the size of Iceland.
Last year, the MIDAS team published a study in the journal Cryosphere describing how Larsen C is currently melting from the surface and the base, and now its gigantic fracture is cracking at a rate no one could have predicted.
Once the outer edge breaks free, researchers are predicting an iceberg measuring about 6,000 square kilometres (2,316 square miles) - close to the size of Delaware - will fall off into the ocean.
"If this will calve off in the next, say two or three years, the calving front will be retreated very far back, further than we’ve seen it since we were able to monitor this," one of the team, Daniela Jansen from the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research in Germany, told Chris Mooney at The Washington Post.
"And our theory in this paper was basically that the calving front might become unstable. Once the iceberg has calved off completely, there might be a tendency for the ice front to crumble backwards."
Just to add to Larsen C’s woes, a separate study published in Nature Communications in June found that meltponds have been forming on the surface - something that’s just recently been found by the thousands on the Langhovde Glacier in East Antarctica.
This will only serve to accelerate the disintegration process.
If Larsen C did end up losing all its ice, scientists have predicted that this could raise global sea levels by around 10 cm (3.9 inches).
massive_breaks_ice_crack_threatening_to_cause_an_entire_Antarctic_ continent

But let’s not get ahead of ourselves here. As Mooney points out, a large loss of ice from Larsen C won’t necessarily be a terrible thing for the world’s oceans - not immediately, at least.

"A study earlier this year in Nature Climate Change looked at ice shelves around Antarctica to determine how much area they could lose without ceasing to form their crucial function of buttressing glaciers and holding them back, and found that Larsen C actually has a lot of 'passive' ice that it can lose without major consequences," he says.

The MIDAS team isn’t as optimistic, so unfortunately, we’re left to wait and see when this massive chunk will break off, and what the consequences will be for life on Earth. Watch this space.
sciencealert
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July 04, 2016
man-standing-in front-of-ice-mountain-100-years-before-photo

Memories from an ill-fated polar expedition.
Back in 2013, conservationists restoring exploration huts in Antarctica uncovered a box of 100-year-old negatives frozen in a block of ice, which depicted events from one of the most ill-fated polar expeditions ever, the Ross Sea Party.
Despite being frozen for a century, the team was able to restore the 22 pictures, offering a never-before-seen look at the tragic event.  
According to the team - a group of conservationists working with New Zealand’sAntarctic Heritage Trust (NZAHT) - the photos were taken by members of the Ross Sea Party who was working with the famed polar explorer Ernest Shackleton during his mission to cross the continent from 1915 to 1917.
To truly understand just how important these photos are, let’s go over the insane events that befell the Shackleton and his crew as they tried to conquer one of the most inhospitable places on Earth.
The story of Shackleton starts way back in December 1914, when the explorer and his crew set out to march across the Antarctic continent - a task that no one had ever achieved.

The plan was to have one crew, led by Shackleton, enter the continent from South Georgia while the other - the Ross Sea Party - made a supply route from the Australian side of the continent. These two would essentially meet up in the middle, an outcome that didn’t even come close to happening.

Here are the frozen negatives recovered from the Ross Sea Party mission 100 years later (more photos below):


So what went so wrong? After sailing within sight of the Antarctic continent in January 1915, Shackleton’s ship Endurance­  quickly came upon pack ice, slowing it to a crawl. The ship pretty much remained in one spot, drifting only as far as the 77th parallel in Vahsel Bay, over the course of nine months.

In September, the ice got so thick, it caused the ship to 'jump' and move as the pressure grew stronger around it. Shackleton eventually gave the order toabandon Endurance in favour of walking over the now thickened ice sheet.
After just three days on the ice, the crew watched as the ship sink into the murky depths below, prompting them to head towards open water in hopes of rescue. They were only able to travel around 2.4 kilometres (1.5 miles) every day.
Come January 1916, Shackleton and his crew had abandoned the quest to open water and, instead, set up a crude settlement called Patience Camp to hopefully wait out the weather.

They were hit by a blizzard, and in March, with food supplies running out, Shackleton ordered the crew to kill all 69 dogs they had with them, saving the youngest to eat later.
In April, the crew managed to reach Elephant Island in three lifeboats, and eventually landed on the shores of South Georgia a few weeks later.
After a 36-hour trek through glacial ice in South Georgia, Shackleton finally found a whaling community and chartered a ship to Elephant Island to pick up his remaining crew. All in all, the 22-month expedition was a complete failure.
While all of this was going on, the Ross Sea Party was on the other side of Antarctica, setting up supply routes for Shackleton to make his way across. Although, just like Shackleton, their expedition was destroyed by inclement weather and disaster after disaster, leading them to become stranded on the continent as well.

Unlike Shackleton’s main party, the Ross Sea Party did manage to complete their mission in full, even after several members of their crew died and their ship sank. The saddest part of their side of the story is that they did it all in vain, because Shackleton never even came close the supply lines they left.
The pictures below are from the Ross Sea Party side of the operation, and they were found in the hut of Captain Robert Falcon Scott - a previous explorer who sheltered there around 1902.
These are some of the only pictures that have been found that showcase what things were like for those in the Ross Sea Party, making them extremely valuable to historians.

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July 02, 2016
earth-outer-layer-or-atmosphere-above-antarctica-is-healing-by-itself
Scientists have found evidence that the hole in the ozone layer over Antarctica is finally beginning to heal. If progress continues, it should be closed permanently by 2050.
The news comes almost 30 years since the world worked together to phase out ozone-depleting chemicals, so we're allowed to give ourselves a little pat on the back. "We can now be confident that the things we’ve done have put the planet on a path to heal," said lead researcher Susan Solomon from MIT.
In the '80s and '90s, the hole in the ozone layer was the environmental threat that everyone was worried about. After decades of pumpingchlorofluorocarbons (CFCs) into the atmosphere - through dry cleaning, aerosols, and old refrigerators - scientists found that the ozone over Antarctica had become seriously thin.
That's not great, seeing as the ozone layer is the shield that absorbs much of the Sun's harmful UV rays before they reach Earth.
To combat the problem, most countries on the planet signed the Montreal Protocol in 1987, which was a global treaty that governed the gradual phase-out of CFCs and other ozone-damaging chemicals.
And now researchers using new longitudinal measurements have shown that the hole is finally starting to heal, and has shrunk by 4 million square kilometres since its peak in 2000. That's roughly half the size of the mainland US.
It did expand to a record size in 2015 due to the eruption of the Chilean volcano, Calbuco, but if environmental progress continues, the hole should be fully closed by mid-century.
"Which is pretty good for us, isn’t it?" said Solomon. "Aren’t we amazing humans, that we did something that created a situation that we decided collectively, as a world, 'Let’s get rid of these molecules'? We got rid of them, and now we’re seeing the planet respond."
Since scientists first started noticing that the ozone hole was getting bigger inthe mid-1980s, they've been monitoring ozone levels every year in October, when moves out of its long winter months and gets sunnier - because chlorine only eats away at ozone when light and cold winds are present.
But the ozone hole starts opening up in August, and Solomon and her team thought they might get more accurate measurements if they tested levels in September, when the temperatures are still cold.
The team was able to show that as chlorine levels in the atmosphere decreased, the rate at which the ozone hole opens up has slowed.
"I think people, myself included, had been too focused on October, because that’s when the ozone hole is enormous, in its full glory," said Solomon. "But October is also subject to the slings and arrows of other things that vary, like slight changes in meteorology. September is a better time to look because chlorine chemistry is firmly in control of the rate at which the hole forms at that time of year. that point hasn’t really been made strongly in the past."
In addition to monitoring the September ozone levels from 2000 to 2015, the team measured the amount of sulphur dioxide emitted by volcanoes each year, which can add to ozone deterioration. They also compared their results with model simulations that predict ozone levels based on the amount of chlorine in the atmosphere each year.
They found that not only did their observations show that the hole was shrinking, it also matched the model's predictions, suggesting that more than half of the change had been driven by the decreasing chlorine in the atmosphere.
"It showed we can actually see a chemical fingerprint, which is sensitive to the levels of chlorine, finally emerging as a sign of recovery," said one of the researchers, Diane Ivy.
The research, which has been published in Science, also shows that we can actually fix some of the damage we've done to the environment when we work together.

"This is a reminder that when the world gets together, we really can solve environmental problems," Solomon told Gizmodo. "I think we should all congratulate ourselves on a job well done."
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