Scientists learn to better understand the movement of Greenland, as it was slowly pushed over the hotspot that is now located under neighboring Iceland. Nothing stands still over geologic time, and even the biggest land masses are constantly being reshaped by Earth.
Credit: Goddard Space Flight Center and Dan Gallagher, Jefferson Beck, Ernie Wright
Credit: Goddard Space Flight Center and Dan Gallagher, Jefferson Beck, Ernie Wright
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TechTranscript
00:01We tend to think of Earth's landmasses as being fixed in place,
00:04but in reality they are attached to moving tectonic plates
00:07that constantly jostle for position and slide over the more viscous mantle beneath.
00:12Case in point, Iceland.
00:15Volcanic eruptions are common on this young landmass,
00:18driven by the two tectonic plates that divide it,
00:20and by its location above a hotspot,
00:23an upwelling of magma that protrudes from deep in the mantle up to the crust.
00:27This hotspot fuels Iceland's eruptions today,
00:31but millions of years ago it was situated beneath neighboring Greenland.
00:35Now, a NASA scientist and her colleagues
00:38have used anomalies in Greenland's crustal magnetic field
00:41to derive its geothermal heat flux.
00:44The researchers also analyzed gravity data and other geophysical information
00:49to effectively peer beneath Greenland's kilometers thick ice sheet
00:53and into the crust itself.
00:55What they found was a thermal track in Greenland's bedrock
00:58that records the motions of a continent over geologic time.
01:02Greenland is part of the North American tectonic plate.
01:05For tens of millions of years,
01:07the plate's movement pushed Greenland over the hotspot.
01:10When the hotspot emerged at the Denmark Strait,
01:13it began raising the seafloor to form Iceland.
01:16Today, a channel of warm bedrock marks the ancient path of the hotspot,
01:20a reminder that nothing stands still over geologic time
01:24and that even the largest land masses
01:26are constantly being reshaped by our dynamic planet.
01:29And the Antarctic planet.
01:30The End