NASA · Monday, September 28, 2026
NASA map finds nearly 2,000 valleys under Greenland’s ice
The File desk · Sep 28, 2026, 10:19 AM UTC
Status
Confirmed (NASA Earth Observatory Image of the Day, Sept. 28, 2026)
NASA’s Earth Observatory made its September 28 Image of the Day a new map of bedrock under the Greenland Ice Sheet. Using Ice Flow Perturbation Analysis — reading faint bumps and dips on the surface as ice flows over buried terrain — researchers manually mapped 1,943 subglacial valleys; about one third are newly identified. About half of the valleys already in BedMachine Greenland, mostly near the ice edge, are now shown to run farther inland, in some cases by hundreds of kilometers. The NASA-led paper is in Geophysical Research Letters (Chartrand et al., 2026; DOI 10.1029/2026GL122028).
NASA’s Earth Observatory made its September 28 Image of the Day a new map of the rock under the Greenland Ice Sheet.
The ice sheet covers 1.7 million square kilometers (656,000 square miles) and measures more than 3 kilometers (1.9 miles) at its thickest point.
The method is called Ice Flow Perturbation Analysis. As ice moves over a valley or a ridge, the buried shape leaves a faint mark on the surface. Satellites map those bumps and dips, and researchers read the land underneath.
Using that technique, researchers manually mapped 1,943 subglacial valleys. About a third of them are newly identified.
About half of the valleys already in BedMachine Greenland, mostly near the ice edge, now run farther inland than that map showed. In some cases the extra reach is hundreds of kilometers.
The page says many of the valleys in the west-central region are long, straight, and lined up from southwest to northeast. Joe MacGregor, a NASA cryospheric scientist and a co-author, said of that orientation, “That’s a riddle to us.”
The NASA-led paper is in Geophysical Research Letters. The citation on the page is Chartrand, A. M., et al. (2026), A Vast Valley Network Beneath the Greenland Ice Sheet, volume 53, number 13, e2026GL122028. The identifier is 10.1029/2026GL122028.
This desk did not open the journal’s own page.
What is still unknown or disputed
- Journal HTML not separately opened this cut; sea-level projection numbers beyond the Earth Observatory text were not independently verified.
Primary sources
Every claim in this story is drawn from the documents below. If a fetch failed, that is recorded on the card.
Source 1
Uncovering the Valleys Hidden Below Greenland’s Ice
NASA Science / Earth Observatory · September 28, 2026
Using the technique, researchers manually mapped 1,943 subglacial valleys beneath the Greenland Ice Sheet, about a third of which are newly identified. Citation: Chartrand, A. M., et al. (2026) A Vast Valley Network Beneath the Greenland Ice Sheet. Geophysical Research Letters, 53 (13), e2026GL122028.
https://science.nasa.gov/earth/earth-observatory/uncovering-the-valleys-hidden-below-greenlands-ice/