New Evidence From Beneath The 'Doomsday' Glacier

#doomsday #glacier #breakthrough

Chapters
0:00 The Doomsday Glacier
0:55 The History Of The Twaites Glacier
2:12 Why Is Thwaites So Dangerous?
4:33 Ad Read
5:35 How Bad is The Doomsday Glacier?
8:20 What We Discovered Below The Doomsday Glacier
13:22 What Do We Do About Thwaites?

A few people have asked so I've added the info below. Some of these are affiliate links. If you make a purchase it doesn't cost you anything extra, but a percentage of the sale will help support this channel.

[DrBenMiles]

Really wishThwaites would 'chill' out - th-waite for us to get our act together - and stop having such a 'melt-down' 🧊🧊🧊

[dperreno]

I thought the thumbnail was of the latest super-deep foam mattress! I can't be the only one...

[bretolpp]

I was in Antartica during '78-'82. I talked to a graduate student who had said his grant was being denied because his research found reduction of ozone layer. This has always been an ironic memory from my time in Antartica.

[gordontingle]

So the people who just found out they were wrong about how the glacier is behaving are now convinced they know how to save the glacier they don’t understand. Using geoengineering to do something never done before with unforeseen consequences to the same thing they already don’t understand. I get skeptical when I say it out loud like that.

[RetiredEE]

If we nuke the Thwaites Glacier first, the ocean can't melt it. 🙂

[matttrevers]

Hi Ben

Thanks for the great video. I'm a glaciologist and I want to just make a couple of comments here.

Firstly, a part of the reason for the potentially rapid retreat of marine-based glaciers on retrograde bedrock slopes is a process known as Marine Ice Sheet Instability (MISI). This process is part of the internal dynamics of the flowing ice. The rate of ice discharge across the grounding line is strongly related to the thickness of ice at the grounding line, so when the grounding line retreats into deeper water, the thicker ice causes increasing flow rates, driving thinning and further retreat in a positive feedback process. However there are still question marks around MISI including the potential for other processes to constrain the rate of retreat.

Secondly, at about 12:55, you discuss the glacier collapsing within a decade, but this isn't a credible prediction, and no study that I know of has ever suggested this. The article you show mentions the Ice Shelf collapsing within a few years. It's very important to distinguish the ice shelf from the ice sheet or glacier. The ice shelf is the floating ice fringing the ice sheet, discharged from the glacier but still attached to it. In some cases, ice shelves are vital to the stability of the glaciers feeding them. However, the Thwaites Ice Shelf is actually a highly fragmented jumble of partially detached blocks of ice. Recent studies have suggested that the Thwaites Ice Shelf isn't particularly crucial to its stability. It is entirely possible that parts of the shelf could collapse within a decade or so, but it is highly unlikely that the partial or even total collapse of the shelf will have an immediate catastrophic impact on the rest of the glacier. Thwaites will almost certainly still be around 100 years from now, possibly in a significantly diminished state but it will still be recognisably Thwaites.

[marilyntaylor]

"Science is the art of finding things out not the art of having all the answers." I like that you are a realist, not an activist.

[djp]

Antarctica has a "west coast?" I thought it only had a north coast.

[MrGoofy]

To be honest I wasn't too surprised that colder water was on top. After all water has a maximum density at about 4°C.

[humblebumblehomestead]

My home is in the tsunami safe zone at 55’ above sea level so I’m totally fine with it not slowing down and eventually having no neighbors

[dixon_est]

Well, somehow I thought that it is a common knowledge, that below 4°C water becomes less dense until it freezes. As water cools below 4°C, the hydrogen-bond network becomes increasingly rigid, forming structures similar to ice. These structures take up more space, lowering the density.

Seems, that this is a surprise to some scientists.
Hint: this is the reason, why water freezes from the top. Not from the bottom.

[yokothespacewhale]

3:00 thanks for this cuz my brain is like “well if it’s already floating then this means nothing” but that illustration is indeed alarming

[OldScientist]

"Overall, the Antarctic ice shelf area has grown by 5305 km² since 2009, with 18 ice shelves retreating and 16 larger shelves growing in area. Our observations show that Antarctic ice shelves gained 661 Gt of ice mass over the past decade." (Andreasen et al, 2023). It is from a paper entitled "Change in Antarctic Ice Shelf Area from 2009 to 2019". They use MODIS (Moderate Resolution Imaging Spectroradiometer) satellite data to measure the change in ice shelf calving front position and area on 34 ice shelves in Antarctica from 2009 to 2019. Also, as the mass gain (661Gt) was given, you could calculate the volume of the ice gained using the formula: Volume = Mass ÷ Density (assume Density of glacier ice 0.9167 Gt/km³). This would give you (well not you obviously) an Ice Gain Volume ≈721km³. That's how much extra of the lovely white stuff there is around Antarctica. Imagine standing in the centre of this extra ice. It would stretch beyond the horizon in all directions and would be 45 storeys high.

[peq_]

Hey ben, not to say any of what you said was false, but could you start sharing sources and whatnot in the description?

For people wanting to read more about it and such

[andrashajdu]

Hey, the water is the most dense at 4•C, thats another reason why -1 at the top and 0.5 at the bottom. Salinity is a plus.

[salinsoulok]

As a representative of Florida we have come to the conclusion that Miami can sink or swim.

Did not expect this kind of attention to this comment.

[chrismcconnell]

I'm in a really bad mood at the moment, but that bit about the marketing team being off the day they named MATHGZ actually put a smile on my face and made me chuckle.

Thank you. I needed that. 🙂

[TheRealHusk]

I think, hear me out, we should open all our fridges at the same time, freezers too, maybe crank up the AC to max. If we get enough people together, maybe we can return to the ice age.

[Scotch]

Professional Floridian here. We will in fact just evolve. Water does not bother us.

[michaelzumpano]

It’s not a mystery that the water is colder against the melting ice surface than below it. The temperature of the water on the undersurface of the ice shelf is colder because the process of melting ice is endothermic. Ice absorbs 333J/g from its surrounding water when it melts. Melting 200g ice (at 0 Celsius) in 1liter of water at 25C results in a 15.9C reduction in water temp. We could probably tell how quickly the ice is melting just by measuring the temperature differential. This has nothing to do with the fact that the melted ice is fresh water. But the fact that it is fresh causes another phenomenon. Fresh water that forms from melted ice against the shelf, is lighter than salt water so it floats above the salty sea water in the absence of mixing and stays against the undersurface of the shelf for a time. But fresh water is colder yet has a slightly lower viscosity than sea water, so under the influence of gravity it might tend to “slide off” the sea water under the slope of the shelf, like liquid slides off a hillside. So maybe that’s how it makes a down-sloping current against the shelf.