How much do we know about Stonehenge? Less than we think. And what has Stonehenge got to do with the Ice Age? More than we might think. This blog is mostly devoted to the problems of where the Stonehenge bluestones came from, and how they got from their source areas to the monument. Now and then I will muse on related Stonehenge topics which have an Ice Age dimension...
Pages
▼
Tuesday, 13 November 2012
Snow tunnel, Kamchatka, Russia
This is an amazing photo of a snow tunnel in Kamchatka, Russia. I can't find out much about this, although I do know that it was taken in an area where there are thick seasonal snowbanks and where meltwater tunnels run beneath them. There is a chance that the meltwater streams might incorporate water from hot springs, because this is a volcanic area. If the water is warm or even tepid, that would obviously enhance its ability to run down to ground level and maintain quite large tunnels.
I'm pretty certain that this is snow rather than glacier ice. The contact between the snow and the underlying boulders does not look like a glacial contact. Note the old water-line, created at a time when the water level in the tunnel was much higher.
Truly beautiful picture Brian.
ReplyDeleteBrian,
ReplyDeleteAmazing photo! Makes my “smart ice theory” pale in comparison!
Kostas
Brian,
ReplyDeleteI am very intrigued by this snow-tunnel photo. I keep looking and looking at it with awe.
Several features I find especially beautiful. The near honeycomb ceiling pattern and the neat piles of round pebbles and stones along each side.
Any idea how these come about? I can understand the piles of rocks and pebbles along the side, as we can see this along many rivers. But what about the ceiling pattern? Perhaps reflecting the gaseous evaporation plumes of the meltwater flow caught in self-created pockets? Just guessing!
Kostas
Yes, it is amazing. As far as the stones are concerned, they are quite well rounded, but not as rounded as you might expect in a fluvioglacial environment -- that means moderate amounts of meltwater, and not flowing at high velocity with a high degree of turbulence. So that is in tune with snowmelt flowing intermittently beneath seasonal snowbanks -- maybe tunnels develop in different positions each year......
ReplyDeleteThe "scalloped" effect on the walls and roof of the tunnel is typical -- you find it in snow tunnels and ice tunnels, and maybe it has something to do with water turbulence.
Brian,
ReplyDeleteThe surface of water is flat. Yet the snow tunnel is tubular. With very 'scalloped' texture on the ceiling.
Turbulence? Perhaps indirectly. But not through contact. The only explanation seems to me to be the heat radiance upward from the surface of water.
Am I correct in thinking so? Or mistaken as usual!
Kostas
The scallops are formed by turbulent flow. A similar effect occurs in cave passages. It is possible to deduce the former velocity of the water from the size of the scallops and the water flow direction from their asymetry.
ReplyDeleteThank you, Anon. Sounds reasonable to me -- turbulent flow of water, or air, or both? You sometimes get scalloping like this on the surface of snowpatches out in the open air too. The contrast with that subglacial tunnel is very striking -- which is why I speculated on a tunnel being completely filled with water flowing under high pressure, and with a spiralling motion -- like the inside of a gun barrel.
ReplyDeleteVery interesting, Anon!
ReplyDeleteAny references where such mathematical relationships are derived? Or at least described? Interested to know the underlying principles for such derivations. Or are these equations empirical. If so, based on what experimental evidence?
But wont the water flow (with linear velocity) smooth out the contact surface? Unless we have here 'standing waves' of turbulence scalloping the contact surface, as I think Brian is suggesting.
Kostas