Ice crystals in glaciers tend to align as the ice flows, creating directional properties that affect how radio waves travel through the ice. Here, we use NASA's Operation Ice Bridge (OIB) radar data to measure this effect (“anisotropy”) in Antarctica and Greenland. Although OIB data were not collected with the goal of measuring anisotropy, locations where radar profiles intersect measure the same ice from two directions, and can be used to infer crystal alignment, even when the survey orientation is unfavorable. Our results show this method is more widely applicable than previously recognized, and highlight key regions of interest which should inform future radar data collection.
