_We expected to find meltwater coming from the ice stream above, a fast-moving channel of ice that flows from the center of the ice sheet toward the ocean. What we didn't expect, but we found in this thick layer of sediments, was a huge amount of groundwater—including saltwater from the ocean._

Scientists discover a vast, salty groundwater system under the Antarctica ice sheet https://phys.org/news/2022-05-scientists-vast-salty-groundwater-antarctica.html