Nature World: Beneath the barren whiteness of Greenland, there lies a mysterious frozen underworld, which through its melting and refreezing process, may be speeding its ice flow to the sea.
Using ice-penetrating radar, researchers have discovered ragged blocks of ice as tall as city skyscrapers and as wide as the island of Manhattan at the very bottom of the ice sheet.
Scientists said the findings, published in the journal Nature Geoscience, could deepen their understanding of how the ice sheets of Greenland...