Researchers have discovered massive blocks of ice which are as wide as Manhattan and as tall as city skyscrapers at the very bottom of the ice sheet in Greenland.
Apparently water beneath the ice sheets refreezes and warps the surrounding ice upwards.
Robin Bell, a geophysicist at Columbia University's Lamont-Doherty Earth Observatory said that the refreezing process uplifts, distorts and warms the ice above, making it softer and easier to flow.
The researchers have revealed that Greenland's glaciers appear to be moving more rapidly toward the sea as climate warms but it remains unclear how the refreeze process will influence this trend.
The study is published in Nature Geoscience.