[Rockhounds] The Arctic Ocean Was Once Filled With Fresh Water, New Research Suggests

[Kreigh Tomaszewski]

Stunning new evidence suggests the Arctic Ocean was covered by a thick
layer of ice and filled with fresh water on at least two occasions during
the past 150,000 years. The observation could finally explain strange and
dramatic climate anomalies associated with these glacial periods.

With all the human-induced melting that’s going on these days, it’s hard to
imagine our world slathered in ice. But such was the case during recent
glacial periods, when significant portions of North America, northern
Europe, Greenland, and parts of the Bering Sea were dominated by massive
ice sheets. With much of Earth’s water tied up in this ice, and with sea
levels dramatically lower than they are today, something very strange
happened, for which we have no modern analogues.

New evidence <https://www.nature.com/articles/s41586-021-03186-y> presented
today in Nature proposes an incredible explanation for the surprising lack
of thorium-230—an isotope that accumulates on the seafloor of salty
oceans—in marine deposits pulled from the sedimentary layers of our
northernmost oceans. This is a potential sign that the Arctic Ocean, cut
off from the rest of the planet’s oceans, featured a basin filled with
fresh water and capped with a 3,000-foot (900-meter) layer of ice.

https://gizmodo.com/the-arctic-ocean-was-once-filled-with-fresh-water-new-1846188557