I What caused this unique ice formation near freezing temperatures?

[Iain]

this ice formation occurred with temperature hovering near zero C. It looks like something that was made in a mould! I suspect that a combination of winds and pressures caused by growing ice crystals in the plastic bucket tilted some crystals which continued to grow.
I

 

[Bystander]

Thank you for sharing that.

 

[rootone]

Two days ago I experienced an interesting ice formation on a local footbridge. (Temperature also about exactly 0C)
Black ice, completely invisible, but as I started the descending side of the bridge my feet just flew away from the rest of me and I was flat on my back.
Still am a bit sore now.

 

[OmCheeto]

Ice spikes! [caltech]

We discussed them about 3 years ago: Weired Ice Cube - How'd it happen? [PF]
And there are probably more.

 

[Iain]

Ice spikes! [caltech]

We discussed them about 3 years ago: Weired Ice Cube - How'd it happen? [PF]
And there are probably more.

Yes I checked out some of the posts. Thanks for the information.
Interestingly, the phenomenon appears fairly often here in Brish Columbia- we live on the east coast of Vancouver Island so it can be quite wet all winter, but we don't usually see low temperatures. Certainly the first time I have seen this happen.

 

[OmCheeto]

Yes I checked out some of the posts. Thanks for the information.
Interestingly, the phenomenon appears fairly often here in Brish Columbia- we live on the east coast of Vancouver Island so it can be quite wet all winter, but we don't usually see low temperatures. Certainly the first time I have seen this happen.

I live about 250 miles south of you, and do not recall seeing one of these until about 2 years ago.
I've been living here for 56 years, so that's a long time not to have noticed something like that.

In a thread predating my presence here at the forum, Strange Ice cube behavior, two members at similar latitudes(40°-48°) also were not familiar with the process.
A third, in Toronto, was able to identify the phenomenon.

Here's a picture of mine, taken January of 2014.

I was very proud of it.

 

[Iain]

I live about 250 miles south of you, and do not recall seeing one of these until about 2 years ago.
I've been living here for 56 years, so that's a long time not to have noticed something like that.

In a thread predating my presence here at the forum, Strange Ice cube behavior, two members at similar latitudes(40°-48°) also were not familiar with the process.
A third, in Toronto, was able to identify the phenomenon.

Here's a picture of mine, taken January of 2014.

I was very proud of it.

That is a neat shot! Unless you see one in person, I gather some people will declare the phenomenon to be impossible.
Some food for thought going on here. While I haven't been able to get a measurement on the angles, I found that in the case I photographed, there were two related objects: one was a triangular stalagmite shape, the other larger object is a hollow triangular "vase" shape. The angles of the triangles seem to be very similar whether a solid or vase-like structure. I also note that the structures appear to have a distinctive lean, again apparently the same whether solid or hollow.
Whilst researching ice, I read that ice takes on cubic or trapezoidal crystal forms. I wonder now if there is some relationship whereby the typical hexagonal shape adopted by ice crystals in the air-i.e. snowflakes and the trapezoidal form we see influence each other. The triangles are suggestive!

 

[DaveC426913]

https://en.wikipedia.org/wiki/Ice_spike

They are caused when water is forced up through a small hole or crack in the ice. The water wets the edges of the hole, then freezes, building up layer by layer.

 

[OmCheeto]

That is a neat shot! Unless you see one in person, I gather some people will declare the phenomenon to be impossible.
Some food for thought going on here. While I haven't been able to get a measurement on the angles, I found that in the case I photographed, there were two related objects: one was a triangular stalagmite shape, the other larger object is a hollow triangular "vase" shape. The angles of the triangles seem to be very similar whether a solid or vase-like structure. I also note that the structures appear to have a distinctive lean, again apparently the same whether solid or hollow.
Whilst researching ice, I read that ice takes on cubic or trapezoidal crystal forms. I wonder now if there is some relationship whereby the typical hexagonal shape adopted by ice crystals in the air-i.e. snowflakes and the trapezoidal form we see influence each other. The triangles are suggestive!

I have no idea how those other shapes form, and wiki's "Mechanism of formation" explanation is a bit too long and story-problem-ish for me to follow. ps. Hey! I've been to Nanaimo! Can't remember a thing about it. That was back in 1983, a few days after the queen visited Victoria. I got to see the queen!

 

[A.T.]