The Arctic Ocean was covered by a shelf ice and filled with freshwater
awi.de
awi.de
> Here we provide evidence for at least two episodes during which the Arctic Ocean and the adjacent Nordic seas were not only covered by an extensive ice shelf, but also filled entirely with fresh water, causing a widespread absence of thorium-230 in marine sediments. We propose that these Arctic freshwater intervals occurred 70,000–62,000 years before present and approximately 150,000–131,000 years before present, corresponding to portions of marine isotope stages 4 and 6.
> A freshwater mass of this size—stored in oceans, rather than land—suggests that a revision of sea-level reconstructions based on freshwater-sensitive stable oxygen isotopes may be required, and that large masses of fresh water could be delivered to the north Atlantic Ocean on very short timescales.
When had most of the salt dissolved into the sea?
I left out lots of stuff, like chemical weathering, thermohaline circulation, glacial damming, and Milankovich cycles which probably explain a lot more... but I’m a climatologist not a geologist so there’s a whole lot more about the chemistry I don’t understand.
Hazen's mineral evolution story was made into a NOVA. Some years back, before the NOVA, it had anecdotally been used down to high-school, but he didn't know of any attempts at middle or primary school. But it seems the usual science education dynamic is no one trying, or doing a miserable job of it, rather than hitting a rigid accessibility envelope.
The cluefulness cost space can be surprisingly shaped. Teach a 5-year old that sunlight is white, and so is the Sun, and after that second bit, they're already less confused there than most first-tier astronomy and physical sciences graduate students. I suggest we've little idea yet how early much of science might be taught, because we've been half-assing it.
And pedagogy.
This might be misread as a primordial origin event. Ocean chlorine and sodium residence times are under 100 Myr. So an ongoing process, with rocks dissolving, and excess precipitating.
We get the word salary from salt too
"The Old English ending -wic ... means farm, as in Keswick (cheese farm), or Goswick (goose farm) ... but it might denote a periodic, opportunistic beach market ... for example Lundenwic (London), Gypeswic (Ipswitch) and so on."
Essentially the salt is part of the process where we have fresh water on land, running toward the ocean carrying nutrients/minerals (including salt) into the ocean.
Put that on auto for a few million years and you have the current ocean.
Bilions of tourists urinating in the water.