Is A Monster Ice Shelf About to Collapse . . . Again??
Know thy ice shelf (before it’s gone forever).
One of the largest ice shelves in the world just gave birth to one of the largest icebergs in history. And it could trigger a catastrophic collapse of the entire shelf — the disappearance of which could amplify global sea level rise.
But this isn’t the first ice shelf collapse to happen — and it won’t be the last.
Like any good Norwegian, Carl Anton Larsen didn’t go anywhere without his skis. In 1893, he was in Antarctica — a place only a handful of people had ever been.
And no one had ever skied.
So when he encountered a massive wall of ice never before seen by human eyes, he had no choice but to ski upon it. Little did he know that everything he saw from horizon to horizon would one day bear his name.
The Larsen Ice Shelf.
An ice shelf is a floating sheet of ice permanently affixed to a landmass. They only exist in areas of the world where it is cold enough to support them, like the arctic, Greenland, Russia, and Antarctica.
There used to be several Larsen Ice shelves. Each one designated with a letter, from A to F. But A, B, and C were by far the largest. They congealed around the Antarctic Peninsula, occupying its entire length for thousands of years.
But in recent decades, these ice shelves have been disappearing.
Larsen A disappeared in 1995. It lay right on the tip of the peninsula — positioned only a little over 600 miles from the foot of South America. Larsen A was subject to warmer waters than its siblings. For thousands of years, it waxed and waned until it completely disintegrated.
Never to return.
But It’s disappearance wasn’t as shocking as the collapse of its sibling, Larsen B, 7 years later.
Larsen B had been stable for at least 10,000 years. Longer than recorded civilization. If you’re a young Earth creationist, this makes Larsen B older than the entire universe.
And in 2002 it took only 3 weeks for Larsen B — an ice shelf the size of Rhode Island whose existence predates the written word — to vanish from the face of the Earth.
Now, very little of Larsen B remains. What does remain is expected to be completely gone within the decade.
The Larsen C ice shelf is even larger and older. It has inhabited the antarctic coastline for longer than anatomically modern humans have existed. Over 100,000 years.
And this illustrates how the ice that Carl Anton Larsen skied across is substantially different than any ice he faced in Norway or most ice you have experienced in your lifetime.
Most ice that you encounter is fleeting.
It comes and goes. It’s seasonal. Hardly lasts for more than a couple months at most before it melts away.
The ice in the Larsen B and C is old. Prehistoric even.
Because of its great age and stability, the Larsen ice shelf is more akin to a geologic feature than a bunch of frozen water. Thus, it’s breakup is like the Grand Canyon suddenly crumbling and disappearing forever.
In 2015, a rift appeared in the Larsen C ice shelf.
Over the next several months, the crack grew at an astounded 33 feet per day, reaching over 120 miles in length. On July 12 2017 it finally broke off from the ice shelf entirely, creating a trillion ton iceberg larger than the state of Delaware.
Larsen C is itself the size of Scotland. But the immense size of this calving event points to an increasingly unstable shelf — which could lead to its rapid disintegration — like its sibling, Larsen B.
Because the ice shelf is floating on the ocean, Larsen C is already displacing an amount of water equal to its volume. So it’s melting wouldn’t raise sea levels directly. But it has acted as a catch for glaciers on the mainland of Antarctica.
Losing Larsen C means losing the dam that has been holding back these melting glaciers.
We’ve already seen this happening where Larsen A and B used to be. The glaciers they used to shore up have rapidly thinned, much of them running directly into the ocean.
If Larsen C disappeared, one of the world’s largest collection of glaciers would pour directly into the ocean, raising sea level by as much as 4 inches.
This might not sound like much but it’d only take a sea level rise of a foot to begin the inundation of low-lying cities like Miami and New Orleans.
But the Larsen Ice shelf isn’t the only ice shelf in danger.
The Wilkins Ice Shelf on the southwest side of the Antarctic Peninsula began disintegrating in 2008. In 2009, the last remnants of the shelf disappeared.
The Ross Ice Shelf is the world’s largest ice shelf. Located on the southern side of the continent, it covers an area of sea the size of Spain — almost 7 times as large as Larsen C.
Researchers have kept a close eye on it for years now. If the Antarctic sea warms by just a few degrees, the Ross Ice Shelf could experience a breakup like Larsen — just as rapid but much greater in scale. Because it is currently holding back enough glaciers to cause a 5m or 16 foot sea level rise.
That would be enough to flood almost every coastal city in the entire world.
Ice shelves make up over 10% of Antarctica’s total area.
Much of what we know of Antarctica is ice shelf. If all the ice shelves disappeared, it’d be like the United States losing an area of land larger than the state of Texas. The very geography and ecology of Antarctica would be irreparably altered — as would the entire world.
And all of this is because of global warming.
Due to the increase of CO2 in the atmosphere.
Caused by human activity.
And the Antarctic Peninsula — where the Larsen Ice Shelf currently resides — is one of the fastest warming areas on the planet.
When the Larsen ice shelf will completely disappear is unknown. All we can do is give our best estimates and projections using the evidence available and historical precedent. Because the greatest danger we face isn’t the loss of this ancient ice, it’s an unprecedented future that leaves us all on unstable footing.
It’s been a little over a century since Carl Anton Larsen became the first person to see the Larsen ice shelf. Now it’s only a matter of time before someone becomes the last.
Watch the video: https://youtu.be/5auaw_r5Jz0