# New Mapping Technique Reveals Hidden Valleys Under Greenland's Ice

NASA-led study uncovers vast subglacial valley network reshaping Greenland's geologic understanding.

- **Source:** [NASA](https://www.nasa.gov)
- **Published:** 2026-09-28
- **Topic:** [Data & AI](https://brifing.si/c/data-ai)
- **Original article:** <https://science.nasa.gov/earth/earth-observatory/uncovering-the-valleys-hidden-below-greenlands-ice/>
- **On Brifing:** https://brifing.si/s/d93dbf61-671d-4d79-9dc9-eed6bf86655f

## Revolutionary bedrock mapping

NASA scientists developed Ice Flow Perturbation Analysis to map Greenland's hidden bedrock with unprecedented detail. The technique detects subtle surface deformations caused by underlying topography, revealing 1,943 subglacial valleys - a third newly discovered. This advancement significantly improves upon the existing BedMachine Greenland dataset, particularly in tracking valley extensions hundreds of kilometers further inland than previously known.

## Ancient valley networks

The newly mapped valleys predate Greenland's ice sheet, offering clues to the island's geologic history. Many originate in southern and eastern highlands where the ice sheet first formed. A hidden mountain range with interconnected valleys was discovered near eastern highlands, potentially surviving since the Pliocene epoch. These findings challenge previous assumptions about Greenland's geological stability and formation timeline.

## Puzzling tectonic patterns

West-central Greenland reveals long, straight valleys consistently aligned southwest-northeast, suggesting unexpected tectonic influences. This orientation contradicts Greenland's typical classification as a rigid tectonic block. The wide branching angles of these valleys indicate they were carved not just by surface water but by an extensive groundwater network eroding rock before glaciation, adding complexity to formation theories.

## Ice flow dynamics

Valleys significantly influence current ice sheet behavior, creating a feedback loop where ice flow concentrates in valleys, forming faster-moving glaciers. This process deepens valleys further, particularly evident along western Greenland. The landscape resembles Yosemite's glacial formations, with coastal areas mirroring features like El Capitan. Understanding this dynamic helps predict future ice sheet changes as climate warms.

## Mapping methodology

The technique analyzes minute surface deformations in satellite data where ice flows over buried topography. Researchers manually interpreted these signatures to reconstruct the hidden landscape. This approach provides higher resolution than previous methods, enabling discovery of previously unknown features and more accurate tracking of known valley extensions beneath the massive ice sheet.

## Future ice sheet behavior

As Greenland's ice sheet retreats due to climate change, scientists predict ice flow will increasingly concentrate in existing valleys. The new topographic data allows better long-term projections of ice sheet evolution beyond the next decade. This understanding is crucial for predicting sea level rise and other climate impacts from Greenland's melting ice.

## Geologic implications

The valley network reveals Greenland's landscape was shaped by complex pre-glacial processes, including significant groundwater erosion. The southwest-northeast valley alignment suggests previously unrecognized tectonic influences on the island's formation. These findings require reevaluation of Greenland's geologic history and its relationship to surrounding tectonic plates.

## Scientific significance

This research fundamentally changes our understanding of Greenland's subglacial landscape and its evolution. By combining advanced remote sensing with geological interpretation, scientists have uncovered a more dynamic pre-glacial history than previously assumed. The findings will inform both climate models predicting ice sheet behavior and geological studies of Arctic region formation.

## Sources covering this story

- https://science.nasa.gov/earth/earth-observatory/uncovering-the-valleys-hidden-below-greenlands-ice/ — 

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_Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._