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Ice climbing on an ice berg as it rolls over

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If you know anything about icebergs you'll know how unstable they are. Well Mike Horn and Fred Roux went for an ice climb and certainly got more than they bargained for! 

 https://www.instagram.com/p/CFMVvtQhLZj/

In reply to purplemonkeyelephant:

That looks far too cold for my liking! :D

In reply to purplemonkeyelephant:

What I can't work out is:  if most of an iceberg is underwater, thus acting as a mega sized keel, how would that happen?  Whats the physics?

Impressive stuff though !

1
In reply to purplemonkeyelephant:

That looks exciting!

In reply to mick taylor:

I'm not sure, but I'd guess older icebergs in cold climates probably get eaten away by seawater until their centre of gravity is almost in line with the water level. 

https://www.youtube.com/watch?v=0kBjb1yfabI& this is another good iceberg climbing video, certainly put me off ever having a go!

 Rob Parsons 18 Sep 2020
In reply to mick taylor:

> What I can't work out is:  if most of an iceberg is underwater, thus acting as a mega sized keel, how would that happen?  Whats the physics?

It must depend on the detailed geometry. But if, for example, you picture an iceberg in the shape of a sphere, or a cylinder, then, in spite of the fact that most of the mass is underwater, the entire object is still free to rotate.

Post edited at 14:26
 gooberman-hill 18 Sep 2020
In reply to Carless:

Exciting - in a "time to change my trousers" fashion!

In reply to purplemonkeyelephant:

And Rob:

Aye, sounds about right.  So the sensible thing to do would be to have 4 climbers, simu-climbing at the 4 'corners'.

That's us three plus another - anyone up for it?

In reply to mick taylor:

I'm not sure if my travel insurance would cover it. 

 nniff 18 Sep 2020
In reply to purplemonkeyelephant:

For those of an acquisitive nature, I know where you can find four leashless tools.....

 elsewhere 18 Sep 2020
In reply to nniff:

I guess with iceberg climbing leashless is essential.

 DerwentDiluted 18 Sep 2020
In reply to purplemonkeyelephant:

Why, watching that, did I have in my head   in a broad Scottish accent...

"Contender, yuu will go on ma first whustle,

Gladiator, yuu will go on ma secund whustle" ?

In reply to mick taylor:

Keels are heavy, icebergs are buoyant. Because a small part of the 'berg is above the water line, the centre of buoyancy is below the centre of gravity. Then the stability depends on the geometry of the volumes of the berg above and below the waterline.

 Rob Parsons 18 Sep 2020
In reply to DerwentDiluted:

> Why, watching that, did I have in my head   in a broad Scottish accent...

> "Contender, yuu will go on ma first whustle,

> Gladiator, yuu will go on ma secund whustle" ?


SET the pendulum!

 deepsoup 18 Sep 2020
In reply to purplemonkeyelephant:

> I'm not sure, but I'd guess older icebergs in cold climates probably get eaten away by seawater until their centre of gravity is almost in line with the water level.

An iceberg is probably about 90% as dense as cold sea water, hence why 90% of it is generally below the surface.  (Because sea water adding up to 90% of the volume of the iceberg weighs the same.)

So for a uniform shape, you'd expect the centre of gravity of the thing to remain at the same level relative to the water level as it melts.  A big rectangular slab might sink as it melts from below, whereas a sphere or a cylinder would tend to roll over.  With an irregular shape I guess it'll be a combination of the two.  And I guess there will be times as the shape changes that it becomes very unstable causing it to roll quite suddenly, for the taller and more pointy ones particularly.

Have you ever seen the pub 'game' where you try to balance a coin on a lemon floating in a pint pot of water?  (It's sometimes offered as a kind of competition to encourage people to drop a quid in a charity box: if the lemon rolls over and your coin falls into the water you've lost it, if it doesn't you win the pot.)  Like an iceberg the lemon is only just less dense than the water so the centre of gravity is well below the surface, but the lemon *always* rolls over.

 deepsoup 18 Sep 2020
In reply to elsewhere:

> I guess with iceberg climbing leashless is essential.

I noticed in purplemonkeyelephant's video that the climbers are each carrying a few ice screws and some quickdraws (and, come to think of it, wearing a harness to hang them off).  Surely you'd have to be absolutely insane to place any gear wouldn't you?  Well, even more insane.

 Grahame N 18 Sep 2020
In reply to purplemonkeyelephant:

I like the Instagram comment -

"if you think this is dangerous by climbing standards you aint seen nothing .... this is just the tip of the iceberg"!

In reply to Rob Parsons:

> But if, for example, you picture an iceberg in the shape of a sphere, or a cylinder

Like a treadmill, you say...? Now, imagine you put a jet plane on it...

 Luke90 18 Sep 2020
In reply to purplemonkeyelephant:

Love the ambition of the very brief attempt to try to outpace the roll by climbing! Would have been incredible if they'd pulled it off, like one of those conveyor climbing machines that have started appearing at Awesome Walls.

 Lankyman 18 Sep 2020
In reply to purplemonkeyelephant:

> https://www.youtube.com/watch?v=0kBjb1yfabI& this is another good iceberg climbing video, certainly put me off ever having a go!

If you put those two guys' names together you can get an anagram of 'daft w*nkers'.

 BuzyG 19 Sep 2020
In reply to purplemonkeyelephant:

I"d be interested to know if they tried another berg after that one.  

 Red Rover 20 Sep 2020
In reply to purplemonkeyelephant:

It's an ice climbing version of this

https://www.youtube.com/watch?v=jVyhr7bEJ9E&

In reply to purplemonkeyelephant:

Wonder if cold sea water is any good for washing soiled pants. 

 BuzyG 21 Sep 2020
In reply to Misha:

A good question.  Clearly the reason they escaped from under it was by using jet propulsion.

 waitout 22 Sep 2020
In reply to purplemonkeyelephant:

By Mike Horn standards, a fairly tame morning really.

 ColdWill 22 Sep 2020
In reply to deepsoup:

lucky the belayer hadn't put a screw in, you know to stop them falling in if they slipped..

 Cbee20191 22 Sep 2020
In reply to purplemonkeyelephant:

I love the reaction of the bloke thinking "meh no big deal, ill just keep climbing it as it rotates". 


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