Gas bubbles from rotting vegetation are the likely cause in this instance. See this article for an explanation:
No Stupid Questions
No such thing. Ask away!
!nostupidquestions is a community dedicated to being helpful and answering each others' questions on various topics.
The rules for posting and commenting, besides the rules defined here for lemmy.world, are as follows:
Rules (interactive)
Rule 1- All posts must be legitimate questions. All post titles must include a question.
All posts must be legitimate questions, and all post titles must include a question. Questions that are joke or trolling questions, memes, song lyrics as title, etc. are not allowed here. See Rule 6 for all exceptions.
Rule 2- Your question subject cannot be illegal or NSFW material.
Your question subject cannot be illegal or NSFW material. You will be warned first, banned second.
Rule 3- Do not seek mental, medical and professional help here.
Do not seek mental, medical and professional help here. Breaking this rule will not get you or your post removed, but it will put you at risk, and possibly in danger.
Rule 4- No self promotion or upvote-farming of any kind.
That's it.
Rule 5- No baiting or sealioning or promoting an agenda.
Questions which, instead of being of an innocuous nature, are specifically intended (based on reports and in the opinion of our crack moderation team) to bait users into ideological wars on charged political topics will be removed and the authors warned - or banned - depending on severity.
Rule 6- Regarding META posts and joke questions.
Provided it is about the community itself, you may post non-question posts using the [META] tag on your post title.
On fridays, you are allowed to post meme and troll questions, on the condition that it's in text format only, and conforms with our other rules. These posts MUST include the [NSQ Friday] tag in their title.
If you post a serious question on friday and are looking only for legitimate answers, then please include the [Serious] tag on your post. Irrelevant replies will then be removed by moderators.
Rule 7- You can't intentionally annoy, mock, or harass other members.
If you intentionally annoy, mock, harass, or discriminate against any individual member, you will be removed.
Likewise, if you are a member, sympathiser or a resemblant of a movement that is known to largely hate, mock, discriminate against, and/or want to take lives of a group of people, and you were provably vocal about your hate, then you will be banned on sight.
Rule 8- All comments should try to stay relevant to their parent content.
Rule 9- Reposts from other platforms are not allowed.
Let everyone have their own content.
Rule 10- Majority of bots aren't allowed to participate here.
Credits
Our breathtaking icon was bestowed upon us by @Cevilia!
The greatest banner of all time: by @TheOneWithTheHair!
Looks like the same thing, good explanation.
There are species of seals who actively keep holes open in the ice to use as breathing holes, allowing them to hunt fish even in frozen-over bodies of water.
They're all ocean-dwelling species in the arctic or antarctic oceans, so this isn't the answer to your specific question, but I just think they're neat.
Before reading the "so this isn't the answer to your specific question, but I just think they're neat." My mind went:
A seal? At this time of year? At this time of day? In this part of the country? Localized entirely within their pond?
Yes!
May I see it?
No.
Seymour the lake is on fire!
Seymour's alive! Alive alive alive!
No, Mother, it’s just the Northern Lights
fish farts
Some of these fish are not looking very healthy
Too many carbs in their diet
Too many carps, you say?
Where I grew up has too many carps.
Their slogan is "Where the ducks walk in the fish."
I shit you not, people line up to throw them stale bread.
The Spillway in Linesville, PA.
I'll get back to you with some readings
I'm not a hydrologist, but I suspect it's due to areas of upwelling warmer water. Alternatively, the ice could have formed, but these spots are where the surface was too unstable to permit that (wind?)
Yep, this is it. The ice is thinner in those areas, allowing more heat from the water to reach the surface
That, or some very adventurous ice fishermen were out already. people who ice fish are a strange lot. In the nearest hole, you can see in the center where it was drilled down. They could be trying a new pond looking for where the fish are laying.
(I wouldn't trust the ice this early in the year with my worst enemy- mostly because they could probably break out on the way back up. shhhh)
Ice doesn't form with even thickness naturally, when it warms back up outside, the thinner parts melt faster, and it kind of snowballs due to currents created and stuff like that. So even if the thin areas didn't start out that much thinner, they end up melting way faster anyway.
GOT DAMN LOCH NESS MONSTA I TOLD YOU I AIN'T GOT NO TREE FIDDY
My best hyptothesis is that in the center of each of those disks a hole may have been or still is through which pond water is wicking upwards and melting the snow in a circular fashion before freezing and coming to a halt. Hence the almost perfect circular shape and the weird lighter color in the center ... notice the crack in the center of the disk in the foreground?
Fish ghosts.
Throws dart...
.
Geothermal vents, or radioactive rocks.
The one time when "swamp gas" is the answer, and you miss it. For shame...
Where the fish peed.
That's where decomposing bodies in barrels are releasing gas bubbles as the corpse decomposes. Both because the bubbles are warmer from decomposition and because they disturb the surface of the water, ice formation is disrupted in "warmer below freezing" temperatures.
Source: I'm just winging it bro.
My hypothesis:
So, basic principles out of the way first, dark absorbs more sun, white reflects it. As the snow melts and reveals the darker colored water beneath, this will begin a runaway feedback loop that will slowly melt more and more ice. Assuming it's not too cold out, anyway.
Since this is actually a runaway feedback loop that is going to eventually melt the whole surface of this body of water, we just need to get it started, and everywhere it starts, it'll spread from. All we need, is something that darkens the surface of the snow.
In the case of that center circle, it's hard to make out, but I think I see a stick jutting out in the exact center. A brown stick, no less.
Having been around melting ice a lot I think this is closer to the right answer. Also decomposing things give off heat. Any vegetation that is decomposing will accelerate ice melting.
most likely due to varying depth. More shallow will stay warmer I believe because the earth holds temperature longer.
Source: I have a ground source heat pump, which is equivalent to saying I stayed at a holiday inn last night. But it might still be true.
Some stormwater management ponds have aeration systems.
Swirls in the water?
Bird? Snowball? Looks more "soggy" than melted, necessarily.
It is a neat effect. Have you tried making your own melt circle?
Now i want to know the answer 😫
Just in case you are interested, here is a similar phenomenon - photographed on the moat of Leeds Castle in Kent, UK - back in Jan 2010