Multidecadal observations of the Antarctic ice sheet from restored analog radar records. ...

• Main Authors: Schroeder, Dustin M, Dowdeswell, Julian A, Siegert, Martin J, Bingham, Robert G, Chu, Winnie, MacKie, Emma J, Siegfried, Matthew R, Vega, Katherine I, Emmons, John R, Winstein, Keith
• Format: Article in Journal/Newspaper
• Language: English
• Published: Proceedings of the National Academy of Sciences 2019
• Subjects: Antarctica; archival data; glaciology; radio echo sounding; remote sensing; Antarctic; The Antarctic; Thwaites Glacier; West Antarctica; Antarc*; Ice Sheet; Ice Shelf
• Online Access: https://dx.doi.org/10.17863/cam.43762; https://www.repository.cam.ac.uk/handle/1810/296719

Airborne radar sounding can measure conditions within and beneath polar ice sheets. In Antarctica, most digital radar-sounding data have been collected in the last 2 decades, limiting our ability to understand processes that govern longer-term ice-sheet behavior. Here, we demonstrate how analog radar data collected over 40 y ago in Antarctica can be combined with modern records to quantify multidecadal changes. Specifically, we digitize over 400,000 line kilometers of exploratory Antarctic radar data originally recorded on 35-mm optical film between 1971 and 1979. We leverage the increased geometric and radiometric resolution of our digitization process to show how these data can be used to identify and investigate hydrologic, geologic, and topographic features beneath and within the ice sheet. To highlight their scientific potential, we compare the digitized data with contemporary radar measurements to reveal that the remnant eastern ice shelf of Thwaites Glacier in West Antarctica had thinned between 10 ...