@mike_malaska@deepspace.social
2026-03-11 01:35 UTC
...it turns out even more CaCO3 dissolves than you'd expect.
At some point in the deep ocean, it is so cold and so high pressure, that CaCO3 will dissolve, in tropical waters that is about 4 km down, in polar waters about 1 km down.
But in practice, it seems that more and faster and shallower calcium dissolution is happening than you'd expect.
But....why???
And it turns out, like all fun geology, it's pretty much driven by BIOLOGY. Specifically, little microbes.
Replies (1)
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@mike_malaska@deepspace.social 2026-03-11 01:39
As particle rich calcite laden "snow" comes down from the upper ocean, there are little microbes riding on it. The authors did experiments that shows that those microbes are metabolizing, making locally high (at microbe scale) CO2 concentrations, little acidic waters, maybe some other chemical byproducts that help Ca solubility too. That helps local dissolution which dissolves the calcite that can then LIGHTENS the particles so they fall slower.