<
https://theconversation.com/ancient-poppy-seeds-and-willow-wood-offer-clues-to-the-greenland-ice-sheets-last-meltdown-and-a-glimpse-into-a-warmer-future-233183>
"As we focused our microscope on the soil sample for the first time, bits of
organic material came into view: a tiny poppy seed, the compound eye of an
insect, broken willow twigs and spikemoss spores. Dark-colored spheres produced
by soil fungi dominated our view.
These were unmistakably the remains of an arctic tundra ecosystem – and proof
that Greenland’s entire ice sheet disappeared more recently than people
realize.
These tiny hints of past life came from a most unlikely place – a handful of
soil that had been buried under 2 miles of ice below the summit of the
Greenland ice sheet. Projections of future melting of the ice sheet are
unambiguous: When the ice is gone at the summit, at least 90% of Greenland’s
ice will have melted.
In 1993, drillers at the summit completed the Greenland Ice Sheet Project 2 ice
core, or GISP2, nicknamed the two-mile time machine. The seeds, twigs and
spores we found came from a few inches of soil at the bottom of that core —
soil that had been tucked away dry, untouched for three decades in a windowless
Colorado storage facility.
Our new analysis builds on the work of others who, over the past decade, have
chipped away at the belief that Greenland’s ice sheet was present continuously
since at least 2.6 million years ago when the Pleistocene ice ages began. In
2016, scientists measuring rare isotopes in rock from above and below the GISP2
soil sample used models to suggest that the ice had vanished at least once
within the past 1.1 million years.
Now, by finding well-preserved tundra remains, we have confirmed that
Greenland’s ice sheet had indeed melted before and exposed the land below the
summit long enough for soil to form and for tundra to grow there. That tells us
that the ice sheet is fragile and could melt again."
Via Susan ****
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
