Photography Contest V, Winner


Our congratulations to Alexander Bartolot, the winner of the latest Panda’s Thumb photography contest with his fascinating photograph “Methane ice bubbles in clear lake ice.” Mr. Bartolot’s photograph garnered 21 out of 44 votes. “Mt. Saint Helens crater,” by James Kocher, was second with 7 votes. We will award Mr. Bartolot a copy of Mark Perakh’s book Unintelligent Design.


Congrats, that was an awesome picture!

Congrats Alexander!

Would anyone like to suggest how the bubbles were formed in the ice? Also, why we assume that the gas is methane?

Matt Young said:

Would anyone like to suggest how the bubbles were formed in the ice? Also, why we assume that the gas is methane?

Interesting question. Here is a guess.

Methane is a greenhouse gas. If a bubble rises from the bottom of a lake and encounters clear ice, it is trapped at the bottom of the ice where it absorbs infrared radiation and warms just enough to penetrate into the ice.

Water expands at 4 degrees Celsius; therefore it floats because it is less dense than the warmer water below. So as water continues to freeze and become a solid at the top, the methane can penetrate more easily at the bottom of the forming ice, and as it rises through the ice toward the surface, the trapped methane now loses its heat faster than it absorbs it; the penetration into the ice stops.

If the ice continues to form, the bubble is trapped within the ice as other bubbles are trapped below it. The next day, those bubbles also absorb IR and penetrate into the new ice below those earlier bubbles.

My guess was this: Methane bubbles are discharged from the lake bottom by rotting vegetation. The lake froze over and some bubbles rose to the top, hit the ice, and flattened out. The lake froze deeper and indeed froze around the bubbles and trapped them. Then more bubbles rose to the top, flattened, and were trapped. Then more. And more. I will be very surprised if the methane penetrates the ice, greenhouse gas or no.

The bubbles are stacked vertically because methane is emitted from pinholes in the mud; you can often see bubbles rising from the same place in a quiet lake. In the winter the rate of production of the methane is reduced, so there is plenty of time for the ice to freeze before the next bubble is emitted.

I will also guess that the vertical needles are air that has come out of solution.

Are the bubbles actually flattened; or is an appearance of flattening being produced by the refractive index of the ice and the angle from which this photo was taken?

My suspicion is that if the bubbles are able to absorb IR and become even a few hundredths of a degree warmer than the surrounding water as it is freezing, it will penetrate enough to secure its position as the water freezes. The bonding of the water molecules will be delayed along the surface of the bubble.

That is merely speculation, of course; I hadn’t thought about this issue until you asked the question.

One could experiment with different gases bubbled up under freezing water by replicating in the lab the conditions in which the bubbles in this photo were formed. One would also need replicated a “sun” above the freezing water to see what effect it has.

I don’t know if anyone has done such an experiment; but this could make a good science project for a high school student or college freshman.

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This page contains a single entry by Matt Young published on August 7, 2013 7:55 PM.

Upcoming Public Skeptalk! was the previous entry in this blog.

Y and mtDNA are not Adam and Eve: Part 2 - What it means to be the Most Recent Common Ancestor? is the next entry in this blog.

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