Oldest water on earth, in a Canadian mine (2021)
macleans.ca
macleans.ca
Sadly none of these questions are addressed in the article.
> We might know water as H2O, forgetting everything that’s dissolved in it. For example, a small vial of the Kidd mine water transferred in 2020 to Ingenium—a Crown corporation that runs the Canada Science and Technology Museum in Ottawa—features sediment at the bottom. That’s iron oxide, which precipitated from the water after exposure to oxygen from the air.
A lot of it may be, but some of it isn't.
You can buy quartz, for example that contain water or petroleum sloshing around inside [1] although some think the water could seep in and out over time.
But quartz with fluid inclusions (small bubbles containing water) are completely sealed and have the same composition as they were up to 3 billion years ago. "the fluid in the inclusion is an actual sample of fluid in which the mineral was growing" [2]
Groundwater "age" is typically considered in terms of residence time, that is the period of time between entering the subsurface and exiting at some discharge location. These analyses are often based upon the hydrogeochemistry and the decay rate of known isotopes, hence the mass spectrometer.
Shallow, unconfined aquifers often contain "young" groundwater, on the order of decades or centuries. For example snow melts on a mountain, downhill into a flatter coarse grained area where it enters the groundwater system. The groundwater then moves downdip along the bedrock contour through and into the deeper alluvial basin, eventually naturally discharging into a river or is pumped out at a well.
It would be interesting to read their paper to understand how they (i.e. what isotope) can date back to 1.6 billion years.
https://books.gw-project.org/groundwater-in-our-water-cycle/...
Referring back to your original question, it would be fascinating to find out what percentage of the water molecules in circulation on Earth today date back to the time when water first condensed out of the atmosphere (IIRC ~ 4 billion years ago) - but I'm not sure if that's possible.
Trying to remember school chemistry lessons, when they explained pH, ... I think H2O is in equilibrium with H+ and OH-, perhaps with 1 in 10^7 of the molecules being disassociated at any time (hence pH 7), so a particular H2O molecule doesn't survive for very long. Minutes? Hours? Not years, I think.
ETA: (Unfortunately, it's paywalled at a high price, which I didn't realized when I originally posted this. Apologies).
As a bonus it will leave you thirsty, which will encourage you to open another bottle...
This song haunted me back when I was a kid and learned about the water cycle.
A lake can be a lake but that doesn't mean the water is the same water.
In any solution, the bonds of water molecules are being continuously rearranged. The odds that any of the water molecules leaving such a solution have any of the atoms they started with are infinitesimal.
For the most part, we live in a giant soup of chemistry on this planet. Everything changes all the time, nothing is forever.
Anyway my point is if 1e-7 of the water you drink technically is not a water molecule at that instant, you can draw graphs of how much of the water you drink has been ionized at some point in the past, which requires a lot more motivation to determine the kinetics than I'm capable of.
So, no, essentially none of the water you drink was recently "pee water" or whatever. Yes technically the individual hydrogen and oxygen atoms have quite an extensive ownership history, but the average "age" of an individual water molecule as three atoms with polar covalent non-ionized bonds is surprisingly low in your average glass of tap water. A decent shoulder shrugging "meh" estimate is figure the water molecules in your average pH 7 tap water are about half a day old. Its a lot more than a couple hours and a lot less than a couple months, that's for sure.
The "age" of water in the linked article is how long that bucket was isolated and sealed off from the general ecosystem which conceptually is a different kettle of fish. Or kettle of dissolved isotopes in this case.
I think the title here is failing to be an accurate description, unless I missed something in science class.
My atoms are 13 billion years old or whatever it is. I guess you, me, and water are all the same age. After we die and desiccate our water will be joined to other fremen. Wait..
The 7 in pH 7 meaning neutral comes from 1 in 1e7 molecules of water having broken apart and ionized at any given instant. Like the Taylor Swift song says, they're never ever getting back together. Ever. So the average lifespan of a rando H-O-H thrupple in plain old tap water is about half a day. So by the definition of "hydrogen atom with UUID X" in a monogamous bond with "oxy atom with UUID Y" in a monogamous bond with "another hydrogen atom with UUID Z" that relationship on average lasts about half a day before getting stirred up into a new relationship. In that sense, most water is less than a day old.
The article is defining age of water as in how long it was sealed off from the rest of the ecosystem. In that sense I have a bottle of Crown Royale containing about 60% water in my basement that's been sealed off from the environment, theoretically, for 18 years before it hit the liquor store shelf, or so the marketing claims. Actually a little longer now that it's chilling in my basement. These folks found some water that's been sealed off for a billion years.
So there's decent arguments for both that "a bucket has been sealed for a billion years" vs "this particular organization of atoms has existed substantially less than one day"
That is like a scifi movie. Weird place.
The zinc electrolyzing pool is ... invigorating to walk near.