Scientists drilled deeper than ever beneath the West Antarctic Ice Sheet and found sediment and marine remains showing the area was once open ocean. The 23-million-year record offers key clues about past melting, helping researchers better predict how quickly the ice sheet could retreat and affect future global sea levels.​Scientists drilled deeper than ever beneath the West Antarctic Ice Sheet and found sediment and marine remains showing the area was once open ocean. The 23-million-year record offers key clues about past melting, helping researchers better predict how quickly the ice sheet could retreat and affect future global sea levels.  ​ science