Posted on 12/14/2023 6:04:58 PM PST by DoodleBob
The longest core of rock ever extracted from beneath Greenland’s thick ice could hold clues about how quickly the island’s frozen covering will melt as the planet warms.
Preliminary analysis of the rock and associated sediment suggests that, at some time in the past three million years or so, the material in this core was exposed to air. That means that the ice atop it had melted away, at least temporarily.
The work adds to a small but growing cadre of studies that use Greenland’s bedrock to illuminate how unstable the overlying ice has been in the past
…
Using the latest equipment, the US$7-million GreenDrill project succeeded this year. It drilled through 509 metres of ice at a site called Prudhoe Dome, and pulled up 7.4 metres of frozen sediment and rock.
To understand whether ice covered a particular location in the past, researchers look for radioactive isotopes that are produced in rock when it is exposed to air and cosmic rays, the high-energy particles from space that constantly bombard Earth. The GreenDrill team’s preliminary analysis suggests that the core, especially the portion that is sediment, contains high levels of beryllium-10, which is one of the key isotopes used to study bedrock exposure, Balter-Kennedy reported at the meeting. …
The amount of beryllium-10 corresponds to around 40,000 years of exposure to air, Balter-Kennedy says. That exposure could have been a single, continuous event, or, more likely, multiple episodes spread over the past few million years. The researchers’ calculations suggest that, if the Prudhoe Dome site was indeed ice-free, whether for short periods of time or a long one, then Greenland must have melted enough to contribute between 19 and 73 centimetres of global sea-level rise.
(Excerpt) Read more at nature.com ...
But wouldn’t plate tectonics play a role in this? Greenland is up by the Arctic Circle today, but through continental drift, wouldn’t Greenland have been somewhere else millions of years ago? Someplace warmer?
Glacier Girl is a P-38 Lightning fighter. Lost in weather, the pilot belly landed on the Greenland glacier in 1942. Fifty years later it was recovered under 300 feet of ice. It was brought to the surface and restored.
It didn’t -sink- in the ice. It sat on the surface, and the glacier grew 300 feet deeper since 1942.
Global warming and melting ice caps indeed.
And it all melted long before the advent of cars...planes....electricity...etc.
Not in just 3 million years.
What did they find?
Let me guess, a half can of Coke and a whole Big Mac burger.
Both items still safe enough to eat!
Native Americans didn’t swim here.
They walked over the Eurasian-North American land bridge.
When you read Geology you discover this planets climate has been all over the place prior to people!
Ice melts and freezes, who knew?
Reunite Pangea!
Yes, but that takes a lot longer.
Continental drift is very slow to affect this.
I should say water freezes and melts and re freezes, who knew?
So drilled down 509 meters to pull up 7.4 meters to find that some melted before. I think the question is not some melted but how did over 500 meters of ice form on top?
This is 40,000 years. Not 40 million. Greenland has not moved so far due to drift in that time.
I would bet at the MOST it was about 12000 years ago. Something BIG happened back then.
Those pesky dinosaurs drove too many SUVs back in the day, and caused the first melt. Bad dinosaurs!
Maybe that’s why they called it “Greenland”. Ya think?
If dinosaurs were driving SUVs. What were they using as fuel? Since greenerfers believe dinosaurs are fossil fuel.
What was before dinosaurs?
Strange thoughts floating around my brain
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