Frost Spikes 5: view from the side

[rjlittlefield]

Some of you know that I am fascinated by the frost spikes that form on oil-treated wood of my deck. (See previous posts: 1, 2, 3, 4.)

There was a particularly good crop of them this morning.

The set shown above was on a railing, nicely posed for shooting in profile.

Field width about 3 inches. Field depth about 5 inches, stack of 17 frames.

--Rik

Technical: Canon 300D, Sigma 105 mm f/2.8 macro lens at 1:4, f/11 nominal, 1/25 second, ISO 100, tripod mount, stacked by focus ring.

[Aynia]

Wow. These are amazing.

I'm too new to know you were into frosty spikes.

You are very lucky to get them...

[P_T]

What the heck?!?

How big are those spikes? seems very sharp, would they cut your hand?

[rjlittlefield]

P_T, they're typically around 10 mm in length, and very fragile -- no danger at all. See HERE for images with some scale references in them.

Aynia, I agree -- they are amazing, and I am lucky to have them.

It's still a mystery to me exactly what causes these to form. I have noticed them only on this one type of wood, and only for the last few years. I suppose that they are started by some surface structure that is peculiar to the wood and the oil that it is treated with, and then the crystals just keep extending along their axes. But the details, the details???

--Rik

[JW]

Rik

Are you still getting these?

Similar examples are not uncommon in the mineral and materials science world. They usually grow from the base, as material is rejected from the matrix, older material is pushed upwards, forming spikes, curly-cue's, columns, etc... I imagine that water in the wood freezes and expands, and so is forced outward at specific points (pores?) in the wood, and so forming spikes.

[rjlittlefield]

Are you still getting these?

I vaguely recall that I got a few last winter. It's too warm still this year to have had any chance.

Similar examples are not uncommon in the mineral and materials science world. They usually grow from the base, as material is rejected from the matrix, older material is pushed upwards, forming spikes, curly-cue's, columns, etc... I imagine that water in the wood freezes and expands, and so is forced outward at specific points (pores?) in the wood, and so forming spikes.

Having read some around Linden.g's travails and the background science of trying to grow snowflakes, I'm inclined to think that these form like frost, by direct crystalization from vapor. There's clearly something special about the wood to get them started, but I don't think the water is actually coming from the wood in the sense of growing at the base and pushing the spike outwards. These things are perfectly straight, spiky, clean, and much larger than pores in the wood. (See the other threads linked from the first post here.) It's very different from the "extruded" appearance of some other ice that I know was formed in the way you're describing.

I guess catching a time lapse of them growing would tell for sure. Maybe if they start forming regularly this winter I'll give that a shot.

--Rik

[JW]

Rik

Beating a dead horse, I googled "ice spikes" and of course Wikipedia has an entry - http://en.wikipedia.org/wiki/Ice_spike

Looks like a wicking phenomenon. Time lapse would be interesting, and maybe a new feature for ZS?

Jeff

[rjlittlefield]

Just because a horse is lying down doesn't mean it's dead.

I'm familiar with that entry, and I don't think it applies to the formations in my photos. Again, take a close look at the details. The ejection/freezing forms shown at http://en.wikipedia.org/wiki/Ice_spike are like the rouste ice at http://www.photomacrography.net/forum/v ... php?t=5771 -- roughly linear and standing up in the middle of nowhere, but with a smooth amorphous structure. Contrast that with the crystal forms shown by Linden.g at http://www.photomacrography.net/forum/v ... 865#102865.

--Rik

[desert bluegrass]

It may be akin to the formation of crystals in a solution where the solution cools (in this case the solution is air saturated with water). Take the simple experiment of alum dissolved in hot water. As the solution cools, alum crystals will form around a wick and separate from the water. The air there in Washington state is probably laden with lots of moisture. As the ice crystals begin to form, the moisture begins to form around the initial formation and that is how the crystals begin to grow outward.

I don't know about the exact chemistry explanation but I've watched this happen in my native Virginia Allegheny mountains. Especially when it's foggy and cold as the morning approaches.

Someone else take over here.
Charlton

[JW]

Rik

Its interesting, hopefully they will form again, I think a cross-section through one would be very revealing in terms of the formation mechanism, especially if they turn out to have a central hollow core. Below-freezing imaging may present a photomicrography challange to boot!

regards, Jeff

[BugEZ]

It goes back a ways, but my undergraduate major was meteorology. I took a class in cloud physics and learned that the shape and growth characteristics of ice crystals was highly dependant upon the temperature of formation and the relative humidity when they form. In this instance, in Eastern Washington in the winter months, I am sure they form by direct sublimation from vapor, close to the ground, probably on a clear still night when radiative cooling supercools (cools the layer beyond the saturation point) the air layer closest to the ground. Low relative humidity and a cool local temperature (perhaps 15-20 deg F) would favor the formation of needle like crystals.

Other temperature/humidity combinations would favor flat crystals. My professor contended that if you look at snow flakes, you can tell what the temperature/humidity history of the flake was as it fell through the cloud toward the earth adding needles and plates.

The draft and military service redirected my career away from meteorology toward engineering, but I still enjoy looking at snow flakes.

For more info by folks that actually know something (rather than dimly recollect it) I suggest checking the link below. The morphology diagram is quite helpful.

http://www.its.caltech.edu/~atomic/snow ... primer.htm

Keith

[DQE]

Excerpt:


For more info by folks that actually know something (rather than dimly recollect it) I suggest checking the link below. The morphology diagram is quite helpful.

http://www.its.caltech.edu/~atomic/snow ... primer.htm

=====================

Thanks for this link to the CalTech site. I had forgotten about the site and CalTech's specialization in the physics of ice and snow.

This lengthy review article (PDF) is linked there, too, and I also found it to be helpful:

https://www.its.caltech.edu/~atomic/pub ... _4_R03.pdf

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Rik's photos are as interesting as they are beautiful, IMO. I eagerly look forward to a full explanation and some time-lapse movies!!! (insert friendly grins here)