It has been hypothesized that complex englacial structures identified within the East Antarctic and Greenland ice sheets are generated by (i) water freezing to the ice sheet base and evolving under ice flow. (ii) deformation of ice of varying rheology. or (iii) entrainment of basal material. Using ice-penetrating radar. https://www.roneverhart.com/Western-Digital-Ultrastar-DC-HC530-WUH721414ALE6L1-0F31170-14TB-7-2K-RPM-SATA-6Gb-s-512e-SED-3-5in-Hard-Drive/