By Amit Malewar 2 Dec, 2024
Collected at: https://www.techexplorist.com/nasa-unexpectedly-discovered-city-greenland-ice-sheet/93814/
In April 2024, NASA scientist Chad Greene and a team of engineers flew over the Greenland Ice Sheet, using radar to study the ice beneath. While flying east of Pituffik Space Base, Greene captured a photo of the ice sheet’s surface, and the radar unexpectedly detected something buried beneath the ice.
It turned out to be Camp Century, a Cold War-era U.S. military base built in 1959. The base, which consisted of tunnels carved into the ice, was abandoned in 1967. Over the years, snow and ice have buried it, leaving its structures more than 30 meters (100 feet) below the surface.
Radar works by emitting radio waves and measuring the time it takes for them to return, allowing scientists to map ice surfaces, internal layers, and bedrock. Previous airborne surveys of Camp Century used conventional ground-penetrating radar, which provided a 2D profile of the ice, revealing signs of the base as a blip in the ice layers.
In contrast, the April 2024 flights used NASA’s UAVSAR radar system, which is mounted on the aircraft and captures both downward and sideward views, creating more detailed, dimensional maps of the area.
Greene, a cryospheric scientist at JPL, said, “In the new data, individual structures in the secret city are visible in a way that they’ve never been seen before.”
By comparing the new radar map of Camp Century with historical layout maps, scientists observed that the parallel structures in the radar images align with the tunnels built to house the base’s facilities. However, the added dimensionality of the radar images makes interpretation more complex. For instance, a long line “above” the base represents the ice bed over a mile below the surface. This line appears above the base because the radar return reflects part of the distant ice bed, not the depth of Camp Century itself.
Scientists have previously used conventional radar maps to estimate Camp Century’s depth, helping assess when the melting and thinning of the ice sheet might re-expose the base and any remaining waste. The new UAVSAR image of Camp Century is still being evaluated for its scientific value, though it was captured by chance. Greene and Gardner, who were testing the UAVSAR’s capabilities for mapping ice layers and the ice-bed interface, did not aim to capture the base.
The primary goal was to enhance ice sheet mapping, which will help scientists measure ice thickness in Antarctica and other regions, improving future sea level rise predictions. Detailed knowledge of ice thickness is crucial for understanding how ice sheets will react to climate change and for projecting sea level rise. The test flights that captured the image will support future mapping efforts in Greenland, Antarctica, and beyond.
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