Iceberg

nivrip

nivrip

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This came from a Rig Manager
for Global Marine Drilling
in St. Johns , Newfoundland ..
They actually have to divert the path
of these things away from the rig
by towing them with ships!

Anyway, in this particular case
the water was calm and
the sun was almost directly overhead
so that the diver was able to get into the water
and take this picture.
They estimated the weight at 300,000,000 tons.


attachment.php


Fantastic. :eek:

It would have been nice to have something alongside it to get a true idea of its size. But, you can't have everything. :)
 

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  • Iceberg.webp
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Don't they say that only 10% of an iceberg is above water?
That's why they are so dangerous you only think it's a small bit of ice!

Good find Niv.:thumb:
 
Assumptions:


ρ(ice) = 1000 kg/m³ (it is a tad less, but let's keep things simple)
→ ”volume equals mass”, i.e. V(ice) = 300,000,000 m³.


Camera: 24 x 36 SLR with 35 mm lens, water ”magnifies”, so we assume its ”underwater angle of view” to be that of a 50 mm lens ”in air”, i.e. 27° horizontally (the photo is ”portrait”, not ”landscape”).


We assume the iceberg to be an ellipsoid. We calculate two cases: a) oblate spheroid where a = 1.36 ∙ b, b = c, and b) tri-axial ellipsoid where a = 1.36 ∙b, c = 10 ∙ b.


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Formulas:


<1> V(sphere) = 4/3 ∙ π ∙ r³
<2> V(ellipsoid) = 4/3 ∙ π ∙ a ∙ b ∙ c — (a, b and c are semi-principal axes)
<3> a² + b² = c² — (by perfessor Pythagoras)




Rough (literally) science:


First, let's calculate the radius of a sphere, V = 300,000,000 m³.
<1>: r = 400 m


a) An oblate sphreroid ( a = 1.36 ∙ b, b = c) with the same volume <1>, <2>:
a = 500 m
b = c = 350 m
→ max width = 700 m, max height = 1000 m, height of ”the surfaced part” is 20 % of total height, i.e. 200 m. So... compared with some buildings in London:


Iceberg.jpg



But. There is no such thing as sea water allowing for a mile of visibility — not even for a hundred yards, actually. And, assuming camera & lense & iceberg width [plus some marine scenery for composition] as per above, the photo appears to be taken from a distance of 1700 m from the iceberg <3>.


But it is still a pretty picture. What? Case b), then? OK... if we assume we're watching ”the short end”, and ”the long end” is ten times longer, we get:
a = 240 m
b = 175 m
c = 1750 m
→ the surfaced height would ”only” be 100 m, and our imaginary diver with the camera would be — again, ”only” — 800-900 m away from the iceberg.






Perfessor Urmas, retarded scuba diver & aficionado of all things on the rocks
 
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I was wondering when someone would bring the maths in to it, pity the Professor cant spell!!!
 
feckit said:
... pity the Professor cant spell!!!
Click to expand...

That is indeed a pity; a wee pity, though... compared with the major pity: the perfessor can't speak... um... write, actually... English.


:fool:
 
:eek:Gorr blimey all that calculations and maths made me feel quite unwell and faint and had to take to my bed:lol:
 
Did you never see any whilst conquering the Empire on behalf of us all during you time in the RM Commandos?
Or did you only get to go to sunny places & jungles!
 
Wow Perfessor, I'm really impressed by the maths. :)

But here's a quote for all of you (and this includes me) who find maths not too easy.


"Do not worry about your difficulties in mathematics, I assure you that mine are greater."

And who said that?

Albert Einstein. :D
 
feckit said:
I was wondering when someone would bring the maths in to it, pity the Professor cant spell!!!
Click to expand...

In your above statement the word you've spelt 'cant' should be spelt 'can't' with an apostrophe between the n and the t to take the place of the letter 'o'. The word 'cant', in the English language, has several meanings the most common of which is 'inclination from a vertical or horizontal plane; slope; slant' but it definitely does not mean 'can not' or even cannot'.

People who live in glass houses... ;)

As for the iceberg, never mind the maths, it's just big, innit? :)
 
"Did you never see any whilst conquering the Empire on behalf of us all during you time in the RM Commandos?
Or did you only get to go to sunny places & jungles!"

Did a bit of snow warfare in Norway it was bloody cold and white and kept falling off the skis, in fact very exhausting:cry:, phew!!!



​
 
After a long time I felt dizzy going through a thread. Phew!

I have looked at the picture again and again and have my doubts that it is a straight image taken by a camera in a single shot, I think it was done in photoshop.
 
Quadophile said:
I have looked at the picture again and again and have my doubts that it is a straight image taken by a camera in a single shot, I think it was done in photoshop.
Click to expand...

I wondered the same thing... Theres too much light on the underside, looks almost like its been lit up from below.


EDIT: Busted.

http://www.hoax-slayer.com/iceberg-photo-hoax.shtml


An article about the image on the Diane Farris Gallery website notes:

The picture was not taken by an oil drilling worker and is not a simple, single photograph created by underwater photographer Ralph Clevenger, who had written:

"I created the image as a way of illustrating the concept of what you get is not necessarily what you see. As a professional photographer, I knew that I couldn't get an actual shot of an iceberg the way I envisioned it, so I created the final image by compositing several images I had taken. The two halves of the iceberg are 2 separate shots, one taken in Alaska and one taken in Antarctica (neither is underwater). The only underwater part is the background taken off the coast of California. The sky is the last component. It took a lot of research on lighting and scale to get the berg to look real."
Click to expand...
 
V_R said:
I wondered the same thing... Theres too much light on the underside, looks almost like its been lit up from below.


EDIT: Busted.

http://www.hoax-slayer.com/iceberg-photo-hoax.shtml
Click to expand...

Drat. I thought I already busted it :fool: :

But. There is no such thing as sea water allowing for a mile of visibility — not even for a hundred yards, actually. And, assuming camera & lense & iceberg width [plus some marine scenery for composition] as per above, the photo appears to be taken from a distance of 1700 m from the iceberg <3>.
Click to expand...
I used to dive quite a lot in my misspent youth, and... if a diver can see 50 metres/yards — and by "seeing" I mean the most rudimentary kind of seeing — s/he'd be in ecstasy. Here is a diving video shot in the Maldives — as good as it gets, visibility wise:


Beautiful, non? But pay attention to all things further off (10-20 metres/yards — underwater photography is "wide angle lens stuff"): everything is "blurred".

In fact, whatever there may be 50 metres/yards off, you can't see at all. It just "fades into blue". And, ambient light (sun)... here's how it goes — in CLEAR water:

Fig5.jpg


So... enter Baron Münchhausen: "I took a pretty darn fine picture of a mammoth of an iceberg... that critter was 700 meters wide and 1,000 meters high... heck, I had to swim one mile away so that it would fit into a picture".

50 m vs. 1 mile... again, orders of magnitude. Lies, big lies and whoppers. "I walked 1,000 miles yesterday."
 
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